---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Thu 05/08/08: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:31 AM - sniffle valve in RV 7A (James H Nelson) 2. 06:55 AM - alternative fuel (glen matejcek) 3. 07:48 AM - Re: sniffle valve in RV 7A (David Cudney) 4. 09:15 AM - Re: sniffle valve in RV 7A (SteinAir, Inc.) 5. 01:13 PM - Re: Alodining Prior to Fuel Tank Sealing was Fw: Re: Pro seal remover? (jan) 6. 01:48 PM - Re: Alodining Prior to Fuel Tank Sealing was Fw: Re: Pro seal remover? (Dean Pichon) 7. 02:09 PM - Re: Alodining Prior to Fuel Tank Sealing was Fw: Re: Pro seal remover? (jan) 8. 06:01 PM - Re: Alodining Prior to Fuel Tank Sealing was Fw: Re: Pro seal remover? (scott bilinski) 9. 06:59 PM - Re: sniffle valve in RV 7A (David Cudney) 10. 07:38 PM - Re: sniffle valve in RV 7A (Fiveonepw@aol.com) 11. 08:19 PM - Re: sniffle valve in RV 7A (Fiveonepw@aol.com) 12. 10:23 PM - Aviation Emissions (DEAN PSIROPOULOS) ________________________________ Message 1 _____________________________________ Time: 06:31:18 AM PST US Subject: RV-List: sniffle valve in RV 7A From: James H Nelson I guess I am missing something. With fuel injection, you will not have fuel "dripping" down into the air box. The sniffle valve is necessary with a carburator style fuel system. With that system you can cause raw fuel to exceed the ability of the engine to ingest it. Especially if you have an accelertor pump on the carb. That will possibly let fuel run back into the air filter box. Am I in error? I have AFP system and it has the fuel purge system which will take off all fuel pressure in the shut down phase. During a starting phase the fuel is placed just in front of the intake valve and "should" all be ingested. Jim Nelson IO-360 ________________________________ Message 2 _____________________________________ Time: 06:55:29 AM PST US From: "glen matejcek" Subject: RV-List: alternative fuel Hi All- I tried to send this yesterday, but somehow pooched it. Looks like this could have some serious potential, and be a wonderful thing for us. http://www.insideindianabusiness.com/newsitem.asp?id=29204 glen matejcek aerobubba@earthlink.net ________________________________ Message 3 _____________________________________ Time: 07:48:16 AM PST US From: David Cudney Subject: Re: RV-List: sniffle valve in RV 7A On an IO 360 with horizontal induction mounted forward of a cold air sump, small amounts of gas can pool in the sump after shutdown. A sniffle valve is used to drain these few drops. On May 8, 2008, at 6:25 AM, James H Nelson wrote: > > I guess I am missing something. With fuel injection, you will not > have > fuel "dripping" down into the air box. The sniffle valve is necessary > with a carburator style fuel system. With that system you can cause > raw > fuel to exceed the ability of the engine to ingest it. Especially > if you > have an accelertor pump on the carb. That will possibly let fuel run > back > into the air filter box. Am I in error? I have AFP system and it has > the fuel purge system which will take off all fuel pressure in the > shut > down phase. During a starting phase the fuel is placed just in > front of > the intake valve and "should" all be ingested. > > Jim Nelson > IO-360 > > ________________________________ Message 4 _____________________________________ Time: 09:15:19 AM PST US From: "SteinAir, Inc." Subject: RE: RV-List: sniffle valve in RV 7A Actually you can and will sometimes have fuel drain back down the intake tubes with an injected system. Prime it for a few seconds too long and it'll start dribbling, and sometimes on shutdown you can get a wee bit as well. It's standard practice to at least put a "weep hole" in the FAB or somewhere at the low point to make sure fuel doesn't pool where you don't want it. My 2 cents as usual. Cheers, Stein >-----Original Message----- >From: owner-rv-list-server@matronics.com >[mailto:owner-rv-list-server@matronics.com]On Behalf Of James H Nelson >Sent: Thursday, May 08, 2008 8:26 AM >To: rv-list@matronics.com >Subject: RV-List: sniffle valve in RV 7A > > > >I guess I am missing something. With fuel injection, you will not have >fuel "dripping" down into the air box. The sniffle valve is necessary >with a carburator style fuel system. With that system you can cause raw >fuel to exceed the ability of the engine to ingest it. Especially if you >have an accelertor pump on the carb. That will possibly let fuel run back >into the air filter box. Am I in error? I have AFP system and it has >the fuel purge system which will take off all fuel pressure in the shut >down phase. During a starting phase the fuel is placed just in front of >the intake valve and "should" all be ingested. > >Jim Nelson >IO-360 > > ________________________________ Message 5 _____________________________________ Time: 01:13:02 PM PST US From: jan Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? Thanks Charles ... Jan -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Charles Kuss Sent: 07 May 2008 22:37 Subject: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Proseal remover? I am resending this with the subject line changed to aid in easier searching of the archieves. Charlie Kuss --- On Wed, 5/7/08, Charles Kuss wrote: > From: Charles Kuss > Subject: RE: RV-List: Proseal remover? > To: rv-list@matronics.com > Date: Wednesday, May 7, 2008, 5:35 PM > Jan, > The difference between "clear" and > "gold" Alodine (or Iridite) is only cosmetic. > They add a dye to the "gold" to aid you in > knowing when the chromic conversion process has completed. > I just did a quick search regarding the application of > Pro-Seal or Chem Seal (as supplied by Vans) > Here is what I found. > > http://www.aviationproductsinc.com/Publications/TDS_PDF/TDS_CS3204.pdf > > http://corporateportal.ppg.com/NR/rdonlyres/22FFA52B-AC2C-4D75-AE20-08E03ACF 8EB8/0/asaguide.pdf > > Both simply stress that the surface be clean. > > I only know of several sets of fuel tanks which were built > locally, which were Alodined prior to sealing. No one has > had any sealing problems so far. > > Charlie Kuss > > > > > --- On Wed, 5/7/08, jan > wrote: > > > From: jan > > Subject: RE: RV-List: Proseal remover? > > To: rv-list@matronics.com > > Date: Wednesday, May 7, 2008, 1:22 PM > > Hi Richard, (nothing wrong with perfection .. :-) > ...) > > & Charles > > > > > > > > Is the reason for using clear and gold Alodine purely > > esthetic or is there a > > technical (chemical) reason why they are use on > different > > parts of the > > aircraft (at Boeing) ? I have used the > "gold" > > Alodine quite a lot - prior to > > painting ... on several parts of the RV I am building. > > Especially the spar. > > > > > > > > >From a adhesion point - paint does stick very well > to a > > Alodined surface - > > Does the maker of ProSeal have any official policy on > using > > Alodine prior to > > application of its product? > > > > > > > > Do you know "how many / how widely" the > practice > > of alodining the inside of > > the tanks are ?? > > > > > > > > Jan > > > > > > > > > > > > > > > > > > > > _____ > > > > From: owner-rv-list-server@matronics.com > > [mailto:owner-rv-list-server@matronics.com] On Behalf > Of > > RICHARD MILLER > > Sent: 07 May 2008 00:22 > > To: rv-list@matronics.com > > Subject: Re: RV-List: Proseal remover? > > > > > > > > hi guys > > > > > > > > jan i was taught to be a litle anal retentive and > by > > the way had to > > follow boeing spec's so everything gets alodined. > clear > > for skins and gold > > for every thing else. besides i like the color. and > water > > from bad fuel is > > bad for alum tanks. > > > > > > > > larry if they don't leak now why play with it. but > when > > they start to leak > > change them out when you pull the tank. it should only > take > > about an hour > > per tank. > > > > > > > > about fuel filters, airflow performance has a filter > prior > > to the twin pump > > setup it will stop any thing big enough to damage the > > pumps, but, big but, > > do you want to risk your bird on one fuel filter. > install > > one filter per > > tank prior to the selector valve. and sleep better at > > night. remember the > > airflow system much more pressure then a carb. i have > never > > like the one > > filter idea in certified aircraft. maybe i should > apply for > > an stc for two. > > airflow fuel filters are an annual replacement item, > > don't cheat > > > > Larry Bowen wrote: > > > > FYI, I used domed nut plates on my RV-8 tanks....and > had to > > cut a couple of > > them off because they interfered with the fuel > pick-up. > > Sometimes > > second-guessing uncle Van doesn't pay off.... > > > > -- > > Larry Bowen > > Larry@BowenAero.com > > http://BowenAero.com > > > > On Tue, May 6, 2008 at 2:14 PM, jan > > > > wrote: > > > > Hi Richard, > > > > > > > > I will be doing my hand build tanks later on this > summer. I > > have read your > > article with great interest. First ... I have bought > the > > domed nut plates... > > they are used on commercial planes from what I > understand > > ... and should > > make a perfect seal with a "O" ring .. Then > cover > > the nut plate after > > fitting with pro-seal as a extra safeguard against > leaks. > > > > > > > > Do you recommend alodining the tank skin and the ribs > ?? > > That is a new one > > to me ... I thought cleaning with Aluprep ...rinse > with > > water ... and scuff > > the seams is fine ?? > > > > > > > > Appreciate you comments on this > > > > > > > > Best regards > > > > > > > > Jan > > > > > > > > > > _____ > > > > > > From: owner-rv-list-server@matronics.com > > > > [mailto:owner-rv-list-server@matronics.com > > ] On > > Behalf Of RICHARD MILLER > > Sent: 06 May 2008 14:54 > > To: rv-list@matronics.com > > > > Subject: Re: RV-List: Proseal remover? > > > > > > > > Since we seem to have so many complaints about fuel > leaks, > > lets cover fuel > > tank 101. > > > > > > > > static loads on a fuel tank are less then .5 psi. duct > tape > > can hold .5 psi. > > dynamic loads are variable due to high g loading and > can > > reach 4 > > > > psi, with tank destruction emanate. the problem with > > checking tanks is the > > static pressure loading is applied to all surfaces and > they > > need to be > > stressed to handle that load. most are not ie, the > caps. > > > > > > > > next problem is the inherent movement of the structure > as > > it flexes. tearing > > the sealant bonds. > > > > > > > > so lets assume that you built it close to right and > now > > want to test it. > > water, fuel, any material with the exception of the > > original sealant will > > contaminate the joint during testing. so how do we > remove > > the contaminates? > > we don't contaminate in the first place. the > sealants > > we are using are > > sensitive to contaminates so air or better nitrogen is > the > > testing medium of > > choice. > > > > > > > > after inspecting aircraft with properly applied > pro-seal > > that had over > > twenty years in service, the stuff sticks. sloshing > does > > not work and will > > result in a crash, the unfortunate part of this is > that the > > pilot is always > > the first person at the crash site.. fire and medic > support > > might take a > > little longer arriving. do not slosh tanks > > > > > > > > types of leaks. > > > > > > > > seam leaks, very rare, normally caused by poor > > construction, or extreme g > > loading. > > > > > > > > fastener leaks, more common also caused by high g > loading > > and flexing of the > > structure, compounded but poor sealing practices. all > tank > > fasteners are to > > be installed wet. and then sealed on the inside. > > > > > > > > access plate/fitting leaks, most common. cause > improperly > > applied sealant, > > wrong nut plates , they should be all domed and > sealed. too > > long of screw > > that goes through the nut plate dome. bad gaskets, > failed > > orings. rotation > > of a fitting after sealant has dried. always use two > > wrenches when removing > > lines. > > > > > > > > the primary problem with tank repair is the lack of > > structural integrity of > > this tank. riveted tanks and the repair tricks where > > designed around the > > larger transport type aircraft. pro-seal sticks well > and > > can be a problem to > > break the seams apart without disturbing/destroying > the > > structure. > > > > > > > > the best way that i have found to stop small leaks at > > fasteners and seams is > > to apply a heavy vacuum to the outside of the tank at > the > > effected area to > > draw any remaining fuel out and and suck the sealant > in to > > the void. > > additional rivets added along seam lines while still > wet > > helps to. > > > > > > > > sealant application tricks. > > > > > > > > clean /clean /clean. pro-seal dose not like oil and > most > > primers but loves a > > good cleaned alodined surface. > > > > > > > > mechanical grip/ light scuff on a flaying surface > helps > > with adhesion > > > > > > > > tape applied along side the joints to assist with > clean up > > > > > > > > gloves, this stuff does not like to come off and mek > is bad > > for you > > > > > > > > proper fit of parts, don't expect pro-seal to fill > > gaps. > > > > > > > > don't use to much. or you will get a wavy > structure. > > > > > > > > use type a for seams it helps with waves and type b > for > > fillets and fastener > > sealing > > > > > > > > don't exceed the pot life > > > > > > > > mix it right and use the correct proportions a good > scale > > really helps. > > > > > > > > use the longest pot life you can, i have found that > 1/2 > > stuff to be almost > > useless for most jobs. > > > > > > > > the proper place for sealant is on the inside of the > tank > > not globed on the > > outside beside it looks ugly. > > > > > > > > tips of opening seams > > > > > > > > sharpend putty knives are great but be sure to round > the > > corners to help > > prevent gouges. take your time here. gentle is better. > > > > > > > > removal of sealant > > > > > > > > scotch bright disks work great. wear a mask. and > realodine > > after done. > > > > > > > > tank testing, quick easy and cheap > > > > > > > > connect air/nitrogen supply to vent > > > > connect clear hose to drain about ten feet worth > > > > loop hose to floor and fill with water until you have > a > > loop with three feet > > high on both sides > > > > add nitrogen until the water is four feet higher on > one > > side then the other. > > you now have 2 psi in the tank. care should be taken > here, > > fill slowly. > > > > spray the seams with soapy water and look for bubbles. > use > > hand soap or > > aircraft soap, some soaps are bad for alum. > > > > > > > > how to find that damn mystery leak i have tried > everything > > else. > > > > sometimes really small leaks are the worse to find, > but one > > way to track > > them down is to apply dye-pen developer to the outside > of > > the tank it will > > show up any tiny leaks. over a couple of days. > > > > > > > > and this ends fuel tank 101 hope it helps. > > > > > > > > > > > > rick miller > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > Be a better friend, newshound, and > > > > > > > > http://www.matronics.com/contribution > > > > > > > > > t="_blank">http://www.matronics.com/Navigator?RV-List > > > > a>http://forums.matronics.com > > > > > > > > > > > > > > > > > > _____ > > > > > > > > Be a better friend, newshound, and > > > > > > > > > > > > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ________________________________ Message 6 _____________________________________ Time: 01:48:48 PM PST US From: Dean Pichon Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? Alodining is the recommended surface prep prior to applying polysulfide to an aluminum surface. If you visit the PPG website (http://corporateportal.ppg.com/NA/Aerospace/Sealants/Sealants_Products/Fue lTank_StdTech.htm) you will find that the highest strength (polysulfide) bonds are those made to alodined surfaces. Within the aerospace industry, alodine (a.k.a. Chemf ilm or Irridite or chromate conversion coating)is the the accepted best sur face treatment for polysulfide sealing. Regards, > From: jan@claver.demon.co.uk> To: rv-list@matronics.com> Subject: RE: Alo dining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover?> D jan@claver.demon.co.uk>> > Thanks Charles ...> > Jan> > -----Original Messa ge-----> From: owner-rv-list-server@matronics.com> [mailto:owner-rv-list-se rver@matronics.com] On Behalf Of Charles Kuss> Sent: 07 May 2008 22:37> To: rv-list@matronics.com> Subject: Alodining Prior to Fuel Tank Sealing was F Kuss > > I am resending this with the subject line cha nged to aid in easier searching> of the archieves.> Charlie Kuss> > > > --- On Wed, 5/7/08, Charles Kuss wrote:> > > From: Charle s Kuss > > Subject: RE: RV-List: Proseal remover?> > To : rv-list@matronics.com> > Date: Wednesday, May 7, 2008, 5:35 PM> > Jan,> > The difference between "clear" and> > "gold" Alodine (or Iridite) is only cosmetic.> > They add a dye to the "gold" to aid you in> > knowing when the chromic conversion process has completed.> > I just did a quick search reg arding the application of> > Pro-Seal or Chem Seal (as supplied by Vans)> > Here is what I found.> > > > http://www.aviationproductsinc.com/Publicatio ns/TDS_PDF/TDS_CS3204.pdf> > > >> http://corporateportal.ppg.com/NR/rdonlyr es/22FFA52B-AC2C-4D75-AE20-08E03ACF> 8EB8/0/asaguide.pdf> > > > Both simply stress that the surface be clean.> > > > I only know of several sets of fu el tanks which were built> > locally, which were Alodined prior to sealing. No one has> > had any sealing problems so far.> > > > Charlie Kuss> > > > > > > > > > --- On Wed, 5/7/08, jan > > wrote:> > > > > From: jan > > > Subject: RE: RV-List: Proseal remover?> > > To: rv-list@matronics.com> > > Date: Wednesday, May 7, 2008, 1:22 PM> > > Hi Richard, (nothing wrong with perfection .. :-)> > ...)> > > & Charles> > > > > > > > > > > > Is the reason for using clear and gold Al odine purely> > > esthetic or is there a> > > technical (chemical) reason w hy they are use on> > different> > > parts of the> > > aircraft (at Boeing) ? I have used the> > "gold"> > > Alodine quite a lot - prior to> > > paint ing ... on several parts of the RV I am building.> > > Especially the spar. > > > > > > > > > > > > >From a adhesion point - paint does stick very well > > to a> > > Alodined surface -> > > Does the maker of ProSeal have any of ficial policy on> > using> > > Alodine prior to> > > application of its pro duct?> > > > > > > > > > > > Do you know "how many / how widely" the> > pra ctice> > > of alodining the inside of> > > the tanks are ??> > > > > > > > > > > > Jan > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ___ __ > > > > > > From: owner-rv-list-server@matronics.com> > > [mailto:owner- rv-list-server@matronics.com] On Behalf> > Of> > > RICHARD MILLER> > > Sent : 07 May 2008 00:22> > > To: rv-list@matronics.com> > > Subject: Re: RV-Lis t: Proseal remover?> > > > > > > > > > > > hi guys> > > > > > > > > > > > j an i was taught to be a litle anal retentive and> > by> > > the way had to> > > follow boeing spec's so everything gets alodined.> > clear> > > for sk ins and gold> > > for every thing else. besides i like the color. and> > wa ter> > > from bad fuel is> > > bad for alum tanks.> > > > > > > > > > > > l arry if they don't leak now why play with it. but> > when> > > they start t o leak> > > change them out when you pull the tank. it should only> > take> > > about an hour> > > per tank.> > > > > > > > > > > > about fuel filters , airflow performance has a filter> > prior> > > to the twin pump> > > setu p it will stop any thing big enough to damage the> > > pumps, but, big but, > > > do you want to risk your bird on one fuel filter.> > install> > > one filter per> > > tank prior to the selector valve. and sleep better at> > > night. remember the> > > airflow system much more pressure then a carb. i have> > never> > > like the one> > > filter idea in certified aircraft. may be i should> > apply for> > > an stc for two.> > > airflow fuel filters are an annual replacement item,> > > don't cheat> > > > > > Larry Bowen wrote:> > > > > > FYI, I used domed nut plates on my RV-8 t anks....and> > had to> > > cut a couple of> > > them off because they inter fered with the fuel> > pick-up. > > > Sometimes> > > second-guessing uncle Van doesn't pay off....> > > > > > -- > > > Larry Bowen> > > Larry@BowenAer o.com> > > http://BowenAero.com > > > > > > On Tue, May 6, 2008 at 2:14 PM, jan> > > > > > wrote:> > > > > > Hi Richard,> > > > > > > > > > > > I will be doing my hand build tanks later on this> > summer. I> > > have re ad your> > > article with great interest. First ... I have bought> > the> > > domed nut plates...> > > they are used on commercial planes from what I> > understand> > > ... and should> > > make a perfect seal with a "O" ring .. Then> > cover> > > the nut plate after> > > fitting with pro-seal as a e xtra safeguard against> > leaks.> > > > > > > > > > > > Do you recommend al odining the tank skin and the ribs> > ??> > > That is a new one> > > to me ... I thought cleaning with Aluprep ...rinse> > with> > > water ... and scu ff> > > the seams is fine ??> > > > > > > > > > > > Appreciate you comments on this> > > > > > > > > > > > Best regards> > > > > > > > > > > > Jan> > > > > > > > > > > > > > > _____ > > > > > > > > > From: owner-rv-list-serve r@matronics.com> > > > > > [mail to:owner-rv-list-server@matronics.com> > > ] On> > > Behalf Of RICHARD MILLER> > > Sent: 06 May 2008 14:54 > > > To: rv-list@matronics.com> > > > > > S ubject: Re: RV-List: Proseal remover?> > > > > > > > > > > > Since we seem to have so many complaints about fuel> > leaks,> > > lets cover fuel> > > t ank 101.> > > > > > > > > > > > static loads on a fuel tank are less then . 5 psi. duct> > tape> > > can hold .5 psi.> > > dynamic loads are variable d ue to high g loading and> > can> > > reach 4> > > > > > psi, with tank dest ruction emanate. the problem with> > > checking tanks is the> > > static pr essure loading is applied to all surfaces and> > they> > > need to be> > > stressed to handle that load. most are not ie, the> > caps.> > > > > > > > > > > > next problem is the inherent movement of the structure> > as> > > i t flexes. tearing> > > the sealant bonds.> > > > > > > > > > > > so lets as sume that you built it close to right and> > now> > > want to test it.> > > water, fuel, any material with the exception of the> > > original sealant will> > > contaminate the joint during testing. so how do we> > remove> > > the contaminates?> > > we don't contaminate in the first place. the> > sea lants> > > we are using are> > > sensitive to contaminates so air or better nitrogen is> > the> > > testing medium of> > > choice. > > > > > > > > > > > > after inspecting aircraft with properly applied> > pro-seal> > > that had over> > > twenty years in service, the stuff sticks. sloshing> > does> > > not work and will> > > result in a crash, the unfortunate part of this is> > that the> > > pilot is always> > > the first person at the crash site .. fire and medic> > support> > > might take a> > > little longer arriving. do not slosh tanks> > > > > > > > > > > > types of leaks.> > > > > > > > > > > > seam leaks, very rare, normally caused by poor> > > construction, or extreme g> > > loading.> > > > > > > > > > > > fastener leaks, more common also caused by high g> > loading> > > and flexing of the> > > structure, c ompounded but poor sealing practices. all> > tank> > > fasteners are to> > > be installed wet. and then sealed on the inside.> > > > > > > > > > > > a ccess plate/fitting leaks, most common. cause> > improperly> > > applied se alant,> > > wrong nut plates , they should be all domed and> > sealed. too> > > long of screw> > > that goes through the nut plate dome. bad gaskets,> > failed> > > orings. rotation> > > of a fitting after sealant has dried. always use two> > > wrenches when removing> > > lines.> > > > > > > > > > > > the primary problem with tank repair is the lack of> > > structural inte grity of> > > this tank. riveted tanks and the repair tricks where> > > des igned around the> > > larger transport type aircraft. pro-seal sticks well> > and> > > can be a problem to> > > break the seams apart without disturbi ng/destroying> > the> > > structure.> > > > > > > > > > > > the best way th at i have found to stop small leaks at> > > fasteners and seams is> > > to apply a heavy vacuum to the outside of the tank at> > the> > > effected are a to> > > draw any remaining fuel out and and suck the sealant> > in to> > > the void.> > > additional rivets added along seam lines while still> > we t> > > helps to. > > > > > > > > > > > > sealant application tricks.> > > > > > > > > > > > clean /clean /clean. pro-seal dose not like oil and> > mos t> > > primers but loves a> > > good cleaned alodined surface. > > > > > > > > > > > > mechanical grip/ light scuff on a flaying surface> > helps> > > with adhesion> > > > > > > > > > > > tape applied along side the joints to assist with> > clean up> > > > > > > > > > > > gloves, this stuff does not like to come off and mek> > is bad> > > for you> > > > > > > > > > > > pro per fit of parts, don't expect pro-seal to fill> > > gaps.> > > > > > > > > > > > don't use to much. or you will get a wavy> > structure. > > > > > > > > > > > > use type a for seams it helps with waves and type b> > for> > > fillets and fastener> > > sealing> > > > > > > > > > > > don't exceed the pot life > > > > > > > > > > > > mix it right and use the correct proportio ns a good> > scale> > > really helps.> > > > > > > > > > > > use the longes t pot life you can, i have found that> > 1/2> > > stuff to be almost> > > u seless for most jobs.> > > > > > > > > > > > the proper place for sealant i s on the inside of the> > tank> > > not globed on the> > > outside beside i t looks ugly.> > > > > > > > > > > > tips of opening seams> > > > > > > > > > > > sharpend putty knives are great but be sure to round> > the> > > cor ners to help> > > prevent gouges. take your time here. gentle is better.> > > > > > > > > > > > removal of sealant > > > > > > > > > > > > scotch brig ht disks work great. wear a mask. and> > realodine> > > after done.> > > > > > > > > > > > tank testing, quick easy and cheap> > > > > > > > > > > > c onnect air/nitrogen supply to vent > > > > > > connect clear hose to drain about ten feet worth> > > > > > loop hose to floor and fill with water unti l you have> > a> > > loop with three feet> > > high on both sides > > > > > > add nitrogen until the water is four feet higher on> > one> > > side the n the other.> > > you now have 2 psi in the tank. care should be taken> > h ere,> > > fill slowly.> > > > > > spray the seams with soapy water and look for bubbles.> > use> > > hand soap or> > > aircraft soap, some soaps are b ad for alum.> > > > > > > > > > > > how to find that damn mystery leak i ha ve tried> > everything> > > else.> > > > > > sometimes really small leaks a re the worse to find,> > but one> > > way to track> > > them down is to app ly dye-pen developer to the outside> > of> > > the tank it will> > > show u p any tiny leaks. over a couple of days.> > > > > > > > > > > > and this en ds fuel tank 101 hope it helps.> > > > > > > > > > > > > > > > > > rick mil ler> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > > > > Be a better friend, newshound, and > > > > > > > > > > > > http://www.matronics.com/contribution> > > > > > > > > > > >> > t="_blank">http ://www.matronics.com/Navigator?RV-List> > > > > > a>http://forums.matronics.com> > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > > > > > > > Be a better friend, newshound, and > > > > > > > > > > > > > > > > > > > > Be a better friend, newshound, and > > know-it-all w ith Yahoo! Mobile. Try it now. > > http://mobile.yahoo.com/;_ylt=Ahu06i62 sR8HDtDypao8Wcj9tAcJ> > > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now.> http://mobile.yahoo.com/;_ylt=Ahu06i62sR ========> > > _________________________________________________________________ Get Free (PRODUCT) RED=99 Emoticons, Winks and Display Pics. http://joinred.spaces.live.com?ocid=TXT_HMTG_prodredemoticons_052008 ________________________________ Message 7 _____________________________________ Time: 02:09:49 PM PST US From: jan Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? Thanks guys.... Very interesting reading .... Jan _____ From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Dean Pichon Sent: 08 May 2008 21:44 Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? Alodining is the recommended surface prep prior to applying polysulfide to an aluminum surface. If you visit the PPG website (http://corporateportal.ppg.com/NA/Aerospace/Sealants/Sealants_Products/Fuel Tank_StdTech.htm ) you will find that the highest strength (polysulfide) bonds are those made to alodined surfaces. Within the aerospace industry, alodine (a.k.a. Chemfilm or Irridite or chromate conversion coating)is the the accepted best surface treatment for polysulfide sealing. Regards, > From: jan@claver.demon.co.uk > To: rv-list@matronics.com > Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? > Date: Thu, 8 May 2008 20:27:05 +0100 > > > Thanks Charles ... > > Jan > > -----Original Message----- > From: owner-rv-list-server@matronics.com > [mailto:owner-rv-list-server@matronics.com] On Behalf Of Charles Kuss > Sent: 07 May 2008 22:37 > To: rv-list@matronics.com > Subject: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Proseal > remover? > > > I am resending this with the subject line changed to aid in easier searching > of the archieves. > Charlie Kuss > > > > --- On Wed, 5/7/08, Charles Kuss wrote: > > > From: Charles Kuss > > Subject: RE: RV-List: Proseal remover? > > To: rv-list@matronics.com > > Date: Wednesday, May 7, 2008, 5:35 PM > > Jan, > > The difference between "clear" and > > "gold" Alodine (or Iridite) is only cosmetic. > > They add a dye to the "gold" to aid you in > > knowing when the chromic conversion process has completed. > > I just did a quick search regarding the application of > > Pro-Seal or Chem Seal (as supplied by Vans) > > Here is what I found. > > > > http://www.aviationproductsinc.com/Publications/TDS_PDF/TDS_CS3204.pdf > > > > > http://corporateportal.ppg.com/NR/rdonlyres/22FFA52B-AC2C-4D75-AE20-08E03ACF > 8EB8/0/asaguide.pdf > > > > Both simply stress that the surface be clean. > > > > I only know of several sets of fuel tanks which were built > > locally, which were Alodined prior to sealing. No one has > > had any sealing problems so far. > > > > Charlie Kuss > > > > > > > > > > --- On Wed, 5/7/08, jan > > wrote: > > > > > From: jan > > > Subject: RE: RV-List: Proseal remover? > > > To: rv-list@matronics.com > > > Date: Wednesday, May 7, 2008, 1:22 PM > > > Hi Richard, (nothing wrong with perfection .. :-) > > ...) > > > & Charles > > > > > > > > > > > > Is the reason for using clear and gold Alodine purely > > > esthetic or is there a > > > technical (chemical) reason why they are use on > > different > > > parts of the > > > aircraft (at Boeing) ? I have used the > > "gold" > > > Alodine quite a lot - prior to > > > painting ... on several parts of the RV I am building. > > > Especially the spar. > > > > > > > > > > > > >From a adhesion point - paint does stick very well > > to a > > > Alodined surface - > > > Does the maker of ProSeal have any official policy on > > using > > > Alodine prior to > > > application of its product? > > > > > > > > > > > > Do you know "how many / how widely" the > > practice > > > of alodining the inside of > > > the tanks are ?? > > > > > > > > > > > > Jan > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > From: owner-rv-list-server@matronics.com > > > [mailto:owner-rv-list-server@matronics.com] On Behalf > > Of > > > RICHARD MILLER > > > Sent: 07 May 2008 00:22 > > > To: rv-list@matronics.com > > > Subject: Re: RV-List: Proseal remover? > > > > > > > > > > > > hi guys > > > > > > > > > > > > jan i was taught to be a litle anal retentive and > > by > > > the way had to > > > follow boeing spec's so everything gets alodined. > > clear > > > for skins and gold > > > for every thing else. besides i like the color. and > > water > > > from bad fuel is > > > bad for alum tanks. > > > > > > > > > > > > larry if they don't leak now why play with it. but > > when > > > they start to leak > > > change them out when you pull the tank. it should only > > take > > > about an hour > > > per tank. > > > > > > > > > > > > about fuel filters, airflow performance has a filter > > prior > > > to the twin pump > > > setup it will stop any thing big enough to damage the > > > pumps, but, big but, > > > do you want to risk your bird on one fuel filter. > > install > > > one filter per > > > tank prior to the selector valve. and sleep better at > > > night. remember the > > > airflow system much more pressure then a carb. i have > > never > > > like the one > > > filter idea in certified aircraft. maybe i should > > apply for > > > an stc for two. > > > airflow fuel filters are an annual replacement item, > > > don't cheat > > > > > > Larry Bowen wrote: > > > > > > FYI, I used domed nut plates on my RV-8 tanks....and > > had to > > > cut a couple of > > > them off because they interfered with the fuel > > pick-up. > > > Sometimes > > > second-guessing uncle Van doesn't pay off.... > > > > > > -- > > > Larry Bowen > > > Larry@BowenAero.com > > > http://BowenAero.com > > > > > > On Tue, May 6, 2008 at 2:14 PM, jan > > > > > > wrote: > > > > > > Hi Richard, > > > > > > > > > > > > I will be doing my hand build tanks later on this > > summer. I > > > have read your > > > article with great interest. First ... I have bought > > the > > > domed nut plates... > > > they are used on commercial planes from what I > > understand > > > ... and should > > > make a perfect seal with a "O" ring .. Then > > cover > > > the nut plate after > > > fitting with pro-seal as a extra safeguard against > > leaks. > > > > > > > > > > > > Do you recommend alodining the tank skin and the ribs > > ?? > > > That is a new one > > > to me ... I thought cleaning with Aluprep ...rinse > > with > > > water ... and scuff > > > the seams is fine ?? > > > > > > > > > > > > Appreciate you comments on this > > > > > > > > > > > > Best regards > > > > > > > > > > > > Jan > > > > > > > > > > > > > > > _____ > > > > > > > > > From: owner-rv-list-server@matronics.com > > > > > > [mailto:owner-rv-list-server@matronics.com > > > ] On > > > Behalf Of RICHARD MILLER > > > Sent: 06 May 2008 14:54 > > > To: rv-list@matronics.com > > > > > > Subject: Re: RV-List: Proseal remover? > > > > > > > > > > > > Since we seem to have so many complaints about fuel > > leaks, > > > lets cover fuel > > > tank 101. > > > > > > > > > > > > static loads on a fuel tank are less then .5 psi. duct > > tape > > > can hold .5 psi. > > > dynamic loads are variable due to high g loading and > > can > > > reach 4 > > > > > > psi, with tank destruction emanate. the problem with > > > checking tanks is the > > > static pressure loading is applied to all surfaces and > > they > > > need to be > > > stressed to handle that load. most are not ie, the > > caps. > > > > > > > > > > > > next problem is the inherent movement of the structure > > as > > > it flexes. tearing > > > the sealant bonds. > > > > > > > > > > > > so lets assume that you built it close to right and > > now > > > want to test it. > > > water, fuel, any material with the exception of the > > > original sealant will > > > contaminate the joint during testing. so how do we > > remove > > > the contaminates? > > > we don't contaminate in the first place. the > > sealants > > > we are using are > > > sensitive to contaminates so air or better nitrogen is > > the > > > testing medium of > > > choice. > > > > > > > > > > > > after inspecting aircraft with properly applied > > pro-seal > > > that had over > > > twenty years in service, the stuff sticks. sloshing > > does > > > not work and will > > > result in a crash, the unfortunate part of this is > > that the > > > pilot is always > > > the first person at the crash site.. fire and medic > > support > > > might take a > > > little longer arriving. do not slosh tanks > > > > > > > > > > > > types of leaks. > > > > > > > > > > > > seam leaks, very rare, normally caused by poor > > > construction, or extreme g > > > loading. > > > > > > > > > > > > fastener leaks, more common also caused by high g > > loading > > > and flexing of the > > > structure, compounded but poor sealing practices. all > > tank > > > fasteners are to > > > be installed wet. and then sealed on the inside. > > > > > > > > > > > > access plate/fitting leaks, most common. cause > > improperly > > > applied sealant, > > > wrong nut plates , they should be all domed and > > sealed. too > > > long of screw > > > that goes through the nut plate dome. bad gaskets, > > failed > > > orings. rotation > > > of a fitting after sealant has dried. always use two > > > wrenches when removing > > > lines. > > > > > > > > > > > > the primary problem with tank repair is the lack of > > > structural integrity of > > > this tank. riveted tanks and the repair tricks where > > > designed around the > > > larger transport type aircraft. pro-seal sticks well > > and > > > can be a problem to > > > break the seams apart without disturbing/destroying > > the > > > structure. > > > > > > > > > > > > the best way that i have found to stop small leaks at > > > fasteners and seams is > > > to apply a heavy vacuum to the outside of the tank at > > the > > > effected area to > > > draw any remaining fuel out and and suck the sealant > > in to > > > the void. > > > additional rivets added along seam lines while still > > wet > > > helps to. > > > > > > > > > > > > sealant application tricks. > > > > > > > > > > > > clean /clean /clean. pro-seal dose not like oil and > > most > > > primers but loves a > > > good cleaned alodined surface. > > > > > > > > > > > > mechanical grip/ light scuff on a flaying surface > > helps > > > with adhesion > > > > > > > > > > > > tape applied along side the joints to assist with > > clean up > > > > > > > > > > > > gloves, this stuff does not like to come off and mek > > is bad > > > for you > > > > > > > > > > > > proper fit of parts, don't expect pro-seal to fill > > > gaps. > > > > > > > > > > > > don't use to much. or you will get a wavy > > structure. > > > > > > > > > > > > use type a for seams it helps with waves and type b > > for > > > fillets and fastener > > > sealing > > > > > > > > > > > > don't exceed the pot life > > > > > > > > > > > > mix it right and use the correct proportions a good > > scale > > > really helps. > > > > > > > > > > > > use the longest pot life you can, i have found that > > 1/2 > > > stuff to be almost > > > useless for most jobs. > > > > > > > > > > > > the proper place for sealant is on the inside of the > > tank > > > not globed on the > > > outside beside it looks ugly. > > > > > > > > > > > > tips of opening seams > > > > > > > > > > > > sharpend putty knives are great but be sure to round > > the > > > corners to help > > > prevent gouges. take your time here. gentle is better. > > > > > > > > > > > > removal of sealant > > > > > > > > > > > > scotch bright disks work great. wear a mask. and > > realodine > > > after done. > > > > > > > > > > > > tank testing, quick easy and cheap > > > > > > > > > > > > connect air/nitrogen supply to vent > > > > > > connect clear hose to drain about ten feet worth > > > > > > loop hose to floor and fill with water until you have > > a > > > loop with three feet > > > high on both sides > > > > > > add nitrogen until the water is four feet higher on > > one > > > side then the other. > > > you now have 2 psi in the tank. care should be taken > > here, > > > fill slowly. > > > > > > spray the seams with soapy water and look for bubbles. > > use > > > hand soap or > > > aircraft soap, some soaps are bad for alum. > > > > > > > > > > > > how to find that damn mystery leak i have tried > > everything > > > else. > > > > > > sometimes really small leaks are the worse to find, > > but one > > > way to track > > > them down is to apply dye-pen developer to the outside > > of > > > the tank it will > > > show up any tiny leaks. over a couple of days. > > > > > > > > > > > > and this ends fuel tank 101 hope it helps. > > > > > > > > > > > > > > > > > > rick miller > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > > > > Be a better friend, newshound, and > > > > > > > > > > > > http://www.matronics.com/contribution > > > > > > > > > > > > > > t="_blank">http://www.matronics.com/Navigator?RV-List > > > > > > a>http://forums.matronics.com > > > > > > > > > > > > > > > > > > > > > > > > > > > _____ > > > > > > > > > > > > Be a better friend, newshound, and > > > > > > > > > > > > > > > > > > > > Be a better friend, newshound, and > > know-it-all with Yahoo! Mobile. Try it now. > > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > > Be a better friend, newshound, and > know-it-all with Yahoo! Mobile. Try it now. > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ > > > _____ Get Free (PRODUCT) RED(tm) Emoticons, Winks and Display Pics. Check it out!

Thanks guys…. Very interesting reading ….

 

Jan

 


From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Dean Pichon
Sent: 08 May 2008 21:44
To: rv-list@matronics.com
Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover?

 

Alodining is the recommended surface prep prior to applying polysulfide to an aluminum surface.  If you visit the PPG website
 
(http://corporateportal.ppg.com/NA/Aerospace /Sealants/Sealants_Products/FuelTank_StdTech.htm)
 
you will find that the highest strength (polysulfide) bonds are those made to alodined surfaces.  Within the aerospace industry, alodine (a.k.a. Chemfilm or Irridite or chromate conversion coating)is the the accepted best surface treatment for polysulfide sealing.
 
Regards,


> From: jan@claver.demon.co.uk
> To: rv-list@matronics.com
> Subject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover?
> Date: Thu, 8 May 2008 20:27:05 +0100
>
> --> RV-List message posted by: jan <jan@claver.demon.co.uk>
>
> Thanks Charles ...
>
> Jan
>
> -----Original Message-----
> From: owner-rv-list-server@matronics.com
> [mailto:owner-rv-list-server@matronics.com] On Behalf Of Charles Kuss
> Sent: 07 May 2008 22:37
> To: rv-list@matronics.com
> Subject: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Proseal
> remover?
>
> --> RV-List message posted by: Charles Kuss <chaskuss@yahoo.com>
>
> I am resending this with the subject line changed to aid in easier searching
> of the archieves.
> Charlie Kuss
>
>
>
> --- On Wed, 5/7/08, Charles Kuss <chaskuss@yahoo.com> wrote:
>
> > From: Charles Kuss <chaskuss@yahoo.com>
> > Subject: RE: RV-List: Proseal remover?
> > To: rv-list@matronics.com
> > Date: Wednesday, May 7, 2008, 5:35 PM
> > Jan,
> > The difference between "clear" and
> > "gold" Alodine (or Iridite) is only cosmetic.
> > They add a dye to the "gold" to aid you in
> > knowing when the chromic conversion process has completed.
> > I just did a quick search regarding the application of
> > Pro-Seal or Chem Seal (as supplied by Vans)
> > Here is what I found.
> >
> > http://www.aviationproductsinc.com/Publications/TDS_PDF/TDS_CS3204.pdf > >
> >
> http://corporateportal.ppg.com/NR/rdonlyres/22FFA52B-AC2C-4D75-AE20-08E0 3ACF
> 8EB8/0/asaguide.pdf
> >
> > Both simply stress that the surface be clean.
> >
> > I only know of several sets of fuel tanks which were built
> > locally, which were Alodined prior to sealing. No one has
> > had any sealing problems so far.
> >
> > Charlie Kuss
> >
> >
> >
> >
> > --- On Wed, 5/7/08, jan <jan@claver.demon.co.uk>
> > wrote:
> >
> > > From: jan <jan@claver.demon.co.uk>
> > > Subject: RE: RV-List: Proseal remover?
> > > To: rv-list@matronics.com
> > > Date: Wednesday, May 7, 2008, 1:22 PM
> > > Hi Richard, (nothing wrong with perfection .. :-)
> > ...)
> > > & Charles
> > >
> > >
> > >
> > > Is the reason for using clear and gold Alodine purely
> > > esthetic or is there a
> > > technical (chemical) reason why they are use on
> > different
> > > parts of the
> > > aircraft (at Boeing) ? I have used the
> > "gold"
> > > Alodine quite a lot - prior to
> > > painting ... on several parts of the RV I am building.
> > > Especially the spar.
> > >
> > >
> > >
> > > >From a adhesion point - paint does stick very well
> > to a
> > > Alodined surface -
> > > Does the maker of ProSeal have any official policy on
> > using
> > > Alodine prior to
> > > application of its product?
> > >
> > >
> > >
> > > Do you know "how many / how widely" the
> > practice
> > > of alodining the inside of
> > > the tanks are ??
> > >
> > >
> > >
> > > Jan
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > _____
> > >
> > > From: owner-rv-list-server@matronics.com
> > > [mailto:owner-rv-list-server@matronics.com] On Behalf
> > Of
> > > RICHARD MILLER
> > > Sent: 07 May 2008 00:22
> > > To: rv-list@matronics.com
> > > Subject: Re: RV-List: Proseal remover?
> > >
> > >
> > >
> > > hi guys
> > >
> > >
> > >
> > > jan i was taught to be a litle anal retentive and
> > by
> > > the way had to
> > > follow boeing spec's so everything gets alodined.
> > clear
> > > for skins and gold
> > > for every thing else. besides i like the color. and
> > water
> > > from bad fuel is
> > > bad for alum tanks.
> > >
> > >
> > >
> > > larry if they don't leak now why play with it. but
> > when
> > > they start to leak
> > > change them out when you pull the tank. it should only
> > take
> > > about an hour
> > > per tank.
> > >
> > >
> > >
> > > about fuel filters, airflow performance has a filter
> > prior
> > > to the twin pump
> > > setup it will stop any thing big enough to damage the
> > > pumps, but, big but,
> > > do you want to risk your bird on one fuel filter.
> > install
> > > one filter per
> > > tank prior to the selector valve. and sleep better at
> > > night. remember the
> > > airflow system much more pressure then a carb. i have
> > never
> > > like the one
> > > filter idea in certified aircraft. maybe i should
> > apply for
> > > an stc for two.
> > > airflow fuel filters are an annual replacement item,
> > > don't cheat
> > >
> > > Larry Bowen <larry@bowenaero.com> wrote:
> > >
> > > FYI, I used domed nut plates on my RV-8 tanks....and
> > had to
> > > cut a couple of
> > > them off because they interfered with the fuel
> > pick-up.
> > > Sometimes
> > > second-guessing uncle Van doesn't pay off....
> > >
> > > --
> > > Larry Bowen
> > > Larry@BowenAero.com
> > > http://BowenAero.com <http://bowenaero.com/>
> > >
> > > On Tue, May 6, 2008 at 2:14 PM, jan
> > > <jan@claver.demon.co.uk
> > > <mailto:jan@claver.demon.co.uk> > wrote:
> > >
> > > Hi Richard,
> > >
> > >
> > >
> > > I will be doing my hand build tanks later on this
> > summer. I
> > > have read your
> > > article with great interest. First ... I have bought
> > the
> > > domed nut plates...
> > > they are used on commercial planes from what I
> > understand
> > > ... and should
> > > make a perfect seal with a "O" ring .. Then
> > cover
> > > the nut plate after
> > > fitting with pro-seal as a extra safeguard against
> > leaks.
> > >
> > >
> > >
> > > Do you recommend alodining the tank skin and the ribs
> > ??
> > > That is a new one
> > > to me ... I thought cleaning with Aluprep ...rinse
> > with
> > > water ... and scuff
> > > the seams is fine ??
> > >
> > >
> > >
> > > Appreciate you comments on this
> > >
> > >
> > >
> > > Best regards
> > >
> > >
> > >
> > > Jan
> > >
> > >
> > >
> > >
> > > _____
> > >
> > >
> > > From: owner-rv-list-server@matronics.com
> > > <mailto:owner-rv-list-server@matronics.com>
> > > [mailto:owner-rv-list-server@matronics.com
> > > <mailto:owner-rv-list-server@matronics.com> ] On
> > > Behalf Of RICHARD MILLER
> > > Sent: 06 May 2008 14:54
> > > To: rv-list@matronics.com
> > > <mailto:rv-list@matronics.com>
> > > Subject: Re: RV-List: Proseal remover?
> > >
> > >
> > >
> > > Since we seem to have so many complaints about fuel
> > leaks,
> > > lets cover fuel
> > > tank 101.
> > >
> > >
> > >
> > > static loads on a fuel tank are less then .5 psi. duct
> > tape
> > > can hold .5 psi.
> > > dynamic loads are variable due to high g loading and
> > can
> > > reach 4
> > >
> > > psi, with tank destruction emanate. the problem with
> > > checking tanks is the
> > > static pressure loading is applied to all surfaces and
> > they
> > > need to be
> > > stressed to handle that load. most are not ie, the
> > caps.
> > >
> > >
> > >
> > > next problem is the inherent movement of the structure
> > as
> > > it flexes. tearing
> > > the sealant bonds.
> > >
> > >
> > >
> > > so lets assume that you built it close to right and
> > now
> > > want to test it.
> > > water, fuel, any material with the exception of the
> > > original sealant will
> > > contaminate the joint during testing. so how do we
> > remove
> > > the contaminates?
> > > we don't contaminate in the first place. the
> > sealants
> > > we are using are
> > > sensitive to contaminates so air or better nitrogen is
> > the
> > > testing medium of
> > > choice.
> > >
> > >
> > >
> > > after inspecting aircraft with properly applied
> > pro-seal
> > > that had over
> > > twenty years in service, the stuff sticks. sloshing
> > does
> > > not work and will
> > > result in a crash, the unfortunate part of this is
> > that the
> > > pilot is always
> > > the first person at the crash site.. fire and medic
> > support
> > > might take a
> > > little longer arriving. do not slosh tanks
> > >
> > >
> > >
> > > types of leaks.
> > >
> > >
> > >
> > > seam leaks, very rare, normally caused by poor
> > > construction, or extreme g
> > > loading.
> > >
> > >
> > >
> > > fastener leaks, more common also caused by high g
> > loading
> > > and flexing of the
> > > structure, compounded but poor sealing practices. all
> > tank
> > > fasteners are to
> > > be installed wet. and then sealed on the inside.
> > >
> > >
> > >
> > > access plate/fitting leaks, most common. cause
> > improperly
> > > applied sealant,
> > > wrong nut plates , they should be all domed and
> > sealed. too
> > > long of screw
> > > that goes through the nut plate dome. bad gaskets,
> > failed
> > > orings. rotation
> > > of a fitting after sealant has dried. always use two
> > > wrenches when removing
> > > lines.
> > >
> > >
> > >
> > > the primary problem with tank repair is the lack of
> > > structural integrity of
> > > this tank. riveted tanks and the repair tricks where
> > > designed around the
> > > larger transport type aircraft. pro-seal sticks well
> > and
> > > can be a problem to
> > > break the seams apart without disturbing/destroying
> > the
> > > structure.
> > >
> > >
> > >
> > > the best way that i have found to stop small leaks at
> > > fasteners and seams is
> > > to apply a heavy vacuum to the outside of the tank at
> > the
> > > effected area to
> > > draw any remaining fuel out and and suck the sealant
> > in to
> > > the void.
> > > additional rivets added along seam lines while still
> > wet
> > > helps to.
> > >
> > >
> > >
> > > sealant application tricks.
> > >
> > >
> > >
> > > clean /clean /clean. pro-seal dose not like oil and
> > most
> > > primers but loves a
> > > good cleaned alodined surface.
> > >
> > >
> > >
> > > mechanical grip/ light scuff on a flaying surface
> > helps
> > > with adhesion
> > >
> > >
> > >
> > > tape applied along side the joints to assist with
> > clean up
> > >
> > >
> > >
> > > gloves, this stuff does not like to come off and mek
> > is bad
> > > for you
> > >
> > >
> > >
> > > proper fit of parts, don't expect pro-seal to fill
> > > gaps.
> > >
> > >
> > >
> > > don't use to much. or you will get a wavy
> > structure.
> > >
> > >
> > >
> > > use type a for seams it helps with waves and type b
> > for
> > > fillets and fastener
> > > sealing
> > >
> > >
> > >
> > > don't exceed the pot life
> > >
> > >
> > >
> > > mix it right and use the correct proportions a good
> > scale
> > > really helps.
> > >
> > >
> > >
> > > use the longest pot life you can, i have found that
> > 1/2
> > > stuff to be almost
> > > useless for most jobs.
> > >
> > >
> > >
> > > the proper place for sealant is on the inside of the
> > tank
> > > not globed on the
> > > outside beside it looks ugly.
> > >
> > >
> > >
> > > tips of opening seams
> > >
> > >
> > >
> > > sharpend putty knives are great but be sure to round
> > the
> > > corners to help
> > > prevent gouges. take your time here. gentle is better.
> > >
> > >
> > >
> > > removal of sealant
> > >
> > >
> > >
> > > scotch bright disks work great. wear a mask. and
> > realodine
> > > after done.
> > >
> > >
> > >
> > > tank testing, quick easy and cheap
> > >
> > >
> > >
> > > connect air/nitrogen supply to vent
> > >
> > > connect clear hose to drain about ten feet worth
> > >
> > > loop hose to floor and fill with water until you have
> > a
> > > loop with three feet
> > > high on both sides
> > >
> > > add nitrogen until the water is four feet higher on
> > one
> > > side then the other.
> > > you now have 2 psi in the tank. care should be taken
> > here,
> > > fill slowly.
> > >
> > > spray the seams with soapy water and look for bubbles.
> > use
> > > hand soap or
> > > aircraft soap, some soaps are bad for alum.
> > >
> > >
> > >
> > > how to find that damn mystery leak i have tried
> > everything
> > > else.
> > >
> > > sometimes really small leaks are the worse to find,
> > but one
> > > way to track
> > > them down is to apply dye-pen developer to the outside
> > of
> > > the tank it will
> > > show up any tiny leaks. over a couple of days.
> > >
> > >
> > >
> > > and this ends fuel tank 101 hope it helps.
> > >
> > >
> > >
> > >
> > >
> > > rick miller
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > _____
> > >
> > >
> > > Be a better friend, newshound, and
> > >
> > >
> > >
> > > http://www.matronics.com/contribution
> > > <http://www.matronics.com/contribution>
> > >
> > >
> > >
> > t="_blank">http://www.matronics.com/Navigator?RV-List
> > > <http://www.matronics.com/Navigator?RV-List>
> > > a>http://forums.matronics.com
> > > <http://forums.matronics.com/>
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > _____
> > >
> > >
> > >
> > > Be a better friend, newshound, and
> > >
> > >
> > > <http://www.matronics.com/Navigator?RV-List>
> > > <http://www.matronics.com/contribution>
> >
> >
> >
> > Be a better friend, newshound, and
> > know-it-all with Yahoo! Mobile. Try it now.
> > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
>
>
> Be a better friend, newshound, and
> know-it-all with Yahoo! Mobile. Try it now.
> http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

>
>
>


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________________________________ Message 8 _____________________________________ Time: 06:01:15 PM PST US From: scott bilinski Subject: Re: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover? Used some Pro-Seal on a car projet a while back but then had to remove it.. ....paint remover worked fairly well.=0A=0A-Scott RV-8a=0A=0A=0A=0A=0A--- -- Original Message ----=0AFrom: jan =0ATo: rv-list @matronics.com=0ASent: Thursday, May 8, 2008 2:05:50 PM=0ASubject: RE: Alod ining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover?=0A =0A=0AThanks guys=85. Very interesting reading =85.=0A-=0AJan=0A-=0A=0A ________________________________=0A=0AFrom:owner-rv-list-server@matronics.c om [mailto:owner-rv-list-server@matronics.com] On Behalf Of Dean Pichon=0AS ent: 08 May 2008 21:44=0ATo: rv-list@matronics.com=0ASubject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro seal remover?=0A-=0A Alodining is the recommended surface prep prior to applying polysulfide to an aluminum surface.- If-you visit the PPG website=0A-=0A(http://corp orateportal.ppg.com/NA/Aerospace/Sealants/Sealants_Products/FuelTank_StdTec h.htm)=0A-=0Ayou will find that the highest strength (polysulfide) bonds are those made to alodined surfaces.- Within the aerospace industry, alod ine (a.k.a. Chemfilm or Irridite or chromate conversion coating)is the the accepted best surface treatment for polysulfide sealing.=0A-=0ARegards, =0A=0A=0A> From: jan@claver.demon.co.uk=0A> To: rv-list@matronics.com=0A> S ubject: RE: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pro s eal remover?=0A> Date: Thu, 8 May 2008 20:27:05 +0100=0A> =0A> --> RV-List message posted by: jan =0A> =0A> Thanks Charles ... =0A> =0A> Jan=0A> =0A> -----Original Message-----=0A> From: owner-rv-list-s erver@matronics.com=0A> [mailto:owner-rv-list-server@matronics.com] On Beha lf Of Charles Kuss=0A> Sent: 07 May 2008 22:37=0A> To: rv-list@matronics.co m=0A> Subject: Alodining Prior to Fuel Tank Sealing was Fw: RE: RV-List: Pr askuss@yahoo.com>=0A> =0A> I am resending this with the subject line change d to aid in easier searching=0A> of the archieves.=0A> Charlie Kuss=0A> =0A > =0A> =0A> --- On Wed, 5/7/08, Charles Kuss wrote:=0A > =0A> > From: Charles Kuss =0A> > Subject: RE: RV-List : Proseal remover?=0A> > To: rv-list@matronics.com=0A> > Date: Wednesday, M ay 7, 2008, 5:35 PM=0A> > Jan,=0A> > The difference between "clear" and=0A> > "gold" Alodine (or Iridite) is only cosmetic.=0A> > They add a dye to th e "gold" to aid you in=0A> > knowing when the chromic conversion process ha s completed.=0A> > I just did a quick search regarding the application of =0A> > Pro-Seal or Chem Seal (as supplied by Vans)=0A> > Here is what I fou nd.=0A> > =0A> > http://www.aviationproductsinc.com/Publications/TDS_PDF/TD S_CS3204.pdf=0A> > =0A> >=0A> http://corporateportal.ppg.com/NR/rdonlyres/2 2FFA52B-AC2C-4D75-AE20-08E03ACF=0A> 8EB8/0/asaguide.pdf=0A> > =0A> > Both s imply stress that the surface be clean.=0A> > =0A> > I only know of several sets of fuel tanks which were built=0A> > locally, which were Alodined pri or to sealing. No one has=0A> > had any sealing problems so far.=0A> > =0A> > Charlie Kuss=0A> > =0A> > =0A> > =0A> > =0A> > --- On Wed, 5/7/08, jan < jan@claver.demon.co.uk>=0A> > wrote:=0A> > =0A> > > From: jan =0A> > > Subject: RE: RV-List: Proseal remover?=0A> > > To: rv-l ist@matronics.com=0A> > > Date: Wednesday, May 7, 2008, 1:22 PM=0A> > > Hi Richard, (nothing wrong with perfection .. :-)=0A> > ...)=0A> > > & Charles =0A> > > =0A> > > =0A> > > =0A> > > Is the reason for using clear and gold Alodine purely=0A> > > esthetic or is there a=0A> > > technical (chemical) reason why they are use on=0A> > different=0A> > > parts of the=0A> > > air craft (at Boeing) ? I have used the=0A> > "gold"=0A> > > Alodine quite a lo t - prior to=0A> > > painting ... on several parts of the RV I am building. =0A> > > Especially the spar.=0A> > > =0A> > > =0A> > > =0A> > > >From a ad hesion point - paint does stick very well=0A> > to a=0A> > > Alodined surfa ce -=0A> > > Does the maker of ProSeal have any official policy on=0A> > us ing=0A> > > Alodine prior to=0A> > > application of its product?=0A> > > =0A> > > =0A> > > =0A> > > Do you know "how many / how widely" the=0A> > pr actice=0A> > > of alodining the inside of=0A> > > the tanks are ??=0A> > > =0A> > > =0A> > > =0A> > > Jan =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > _____ =0A> > > =0A> > > From: owner-rv-list-server@matronics.com=0A> > > [mailto:owner-rv-list-server@ma tronics.com] On Behalf=0A> > Of=0A> > > RICHARD MILLER=0A> > > Sent: 07 May 2008 00:22=0A> > > To: rv-list@matronics.com=0A> > > Subject: Re: RV-List: Proseal remover?=0A> > > =0A> > > =0A> > > =0A> > > hi guys=0A> > > =0A> > > =0A> > > =0A> > > jan i was taught to be a litle anal retentive and=0A> > by=0A> > > the way had to=0A> > > follow boeing spec's so everything gets alodined.=0A> > clear=0A> > > for skins and gold=0A> > > for every thing e lse. besides i like the color. and=0A> > water=0A> > > from bad fuel is=0A> > > bad for alum tanks.=0A> > > =0A> > > =0A> > > =0A> > > larry if they d on't leak now why play with it. but=0A> > when=0A> > > they start to leak =0A> > > change them out when you pull the tank. it should only=0A> > take =0A> > > about an hour=0A> > > per tank.=0A> > > =0A> > > =0A> > > =0A> > > about fuel filters, airflow performance has a filter=0A> > prior=0A> > > t o the twin pump=0A> > > setup it will stop any thing big enough to damage t he=0A> > > pumps, but, big but,=0A> > > do you want to risk your bird on on e fuel filter.=0A> > install=0A> > > one filter per=0A> > > tank prior to t he selector valve. and sleep better at=0A> > > night. remember the=0A> > > airflow system much more pressure then a carb. i have=0A> > never=0A> > > l ike the one=0A> > > filter idea in certified aircraft. maybe i should=0A> > apply for=0A> > > an stc for two.=0A> > > airflow fuel filters are an annu al replacement item,=0A> > > don't cheat=0A> > > =0A> > > Larry Bowen wrote:=0A> > > =0A> > > FYI, I used domed nut plates on my RV-8 tanks....and=0A> > had to=0A> > > cut a couple of=0A> > > them off be cause they interfered with the fuel=0A> > pick-up. =0A> > > Sometimes=0A> > > second-guessing uncle Van doesn't pay off....=0A> > > =0A> > > -- =0A> > > Larry Bowen=0A> > > Larry@BowenAero.com=0A> > > http://BowenAero.com =0A> > > =0A> > > On Tue, May 6, 2008 at 2:14 PM, jan =0A> > > > > > wrote:=0A> > > =0A> > > Hi Richard,=0A> > > =0A> > > =0A> > > =0A> > > I wi ll be doing my hand build tanks later on this=0A> > summer. I=0A> > > have read your=0A> > > article with great interest. First ... I have bought=0A> > the=0A> > > domed nut plates...=0A> > > they are used on commercial plane s from what I=0A> > understand=0A> > > ... and should=0A> > > make a perfec t seal with a "O" ring .. Then=0A> > cover=0A> > > the nut plate after=0A> > > fitting with pro-seal as a extra safeguard against=0A> > leaks.=0A> > > =0A> > > =0A> > > =0A> > > Do you recommend alodining the tank skin and th e ribs=0A> > ??=0A> > > That is a new one=0A> > > to me ... I thought clean ing with Aluprep ...rinse=0A> > with=0A> > > water ... and scuff=0A> > > th e seams is fine ??=0A> > > =0A> > > =0A> > > =0A> > > Appreciate you commen ts on this=0A> > > =0A> > > =0A> > > =0A> > > Best regards=0A> > > =0A> > > =0A> > > =0A> > > Jan=0A> > > =0A> > > =0A> > > =0A> > > =0A> > > _____ =0A> > > =0A> > > =0A> > > From: owner-rv-list-server@matronics.com=0A> > > =0A> > > [mailto:owner-rv-list- server@matronics.com=0A> > > ] On=0A> > > Behalf Of RICHARD MILLER=0A> > > Sent: 06 May 2008 14:54=0A> > > To: rv-list@matronics.com=0A> > > =0A> > > Subject: Re: RV-List: Proseal remover?=0A> > > =0A> > > =0A> > > =0A> > > Since we seem to have so many complaints about fuel=0A> > leaks,=0A> > > l ets cover fuel=0A> > > tank 101.=0A> > > =0A> > > =0A> > > =0A> > > static loads on a fuel tank are less then .5 psi. duct=0A> > tape=0A> > > can hold .5 psi.=0A> > > dynamic loads are variable due to high g loading and=0A> > can=0A> > > reach 4=0A> > > =0A> > > psi, with tank destruction emanate. t he problem with=0A> > > checking tanks is the=0A> > > static pressure loadi ng is applied to all surfaces and=0A> > they=0A> > > need to be=0A> > > str essed to handle that load. most are not ie, the=0A> > caps.=0A> > > =0A> > > =0A> > > =0A> > > next problem is the inherent movement of the structure =0A> > as=0A> > > it flexes. tearing=0A> > > the sealant bonds.=0A> > > =0A > > > =0A> > > =0A> > > so lets assume that you built it close to right and =0A> > now=0A> > > want to test it.=0A> > > water, fuel, any material with the exception of the=0A> > > original sealant will=0A> > > contaminate the joint during testing. so how do we=0A> > remove=0A> > > the contaminates? =0A> > > we don't contaminate in the first place. the=0A> > sealants=0A> > > we are using are=0A> > > sensitive to contaminates so air or better nitro gen is=0A> > the=0A> > > testing medium of=0A> > > choice. =0A> > > =0A> > > =0A> > > =0A> > > after inspecting aircraft with properly applied=0A> > p ro-seal=0A> > > that had over=0A> > > twenty years in service, the stuff st icks. sloshing=0A> > does=0A> > > not work and will=0A> > > result in a cra sh, the unfortunate part of this is=0A> > that the=0A> > > pilot is always =0A> > > the first person at the crash site.. fire and medic=0A> > support =0A> > > might take a=0A> > > little longer arriving. do not slosh tanks=0A > > > =0A> > > =0A> > > =0A> > > types of leaks.=0A> > > =0A> > > =0A> > > =0A> > > seam leaks, very rare, normally caused by poor=0A> > > constructio n, or extreme g=0A> > > loading.=0A> > > =0A> > > =0A> > > =0A> > > fastene r leaks, more common also caused by high g=0A> > loading=0A> > > and flexin g of the=0A> > > structure, compounded but poor sealing practices. all=0A> > tank=0A> > > fasteners are to=0A> > > be installed wet. and then sealed o n the inside.=0A> > > =0A> > > =0A> > > =0A> > > access plate/fitting leaks , most common. cause=0A> > improperly=0A> > > applied sealant,=0A> > > wron g nut plates , they should be all domed and=0A> > sealed. too=0A> > > long of screw=0A> > > that goes through the nut plate dome. bad gaskets,=0A> > f ailed=0A> > > orings. rotation=0A> > > of a fitting after sealant has dried . always use two=0A> > > wrenches when removing=0A> > > lines.=0A> > > =0A> > > =0A> > > =0A> > > the primary problem with tank repair is the lack of =0A> > > structural integrity of=0A> > > this tank. riveted tanks and the r epair tricks where=0A> > > designed around the=0A> > > larger transport typ e aircraft. pro-seal sticks well=0A> > and=0A> > > can be a problem to=0A> > > break the seams apart without disturbing/destroying=0A> > the=0A> > > s tructure.=0A> > > =0A> > > =0A> > > =0A> > > the best way that i have found to stop small leaks at=0A> > > fasteners and seams is=0A> > > to apply a h eavy vacuum to the outside of the tank at=0A> > the=0A> > > effected area t o=0A> > > draw any remaining fuel out and and suck the sealant=0A> > in to =0A> > > the void.=0A> > > additional rivets added along seam lines while s till=0A> > wet=0A> > > helps to. =0A> > > =0A> > > =0A> > > =0A> > > sealan t application tricks.=0A> > > =0A> > > =0A> > > =0A> > > clean /clean /clea n. pro-seal dose not like oil and=0A> > most=0A> > > primers but loves a=0A > > > good cleaned alodined surface. =0A> > > =0A> > > =0A> > > =0A> > > me chanical grip/ light scuff on a flaying surface=0A> > helps=0A> > > with ad hesion=0A> > > =0A> > > =0A> > > =0A> > > tape applied along side the joint s to assist with=0A> > clean up=0A> > > =0A> > > =0A> > > =0A> > > gloves, this stuff does not like to come off and mek=0A> > is bad=0A> > > for you =0A> > > =0A> > > =0A> > > =0A> > > proper fit of parts, don't expect pro-s eal to fill=0A> > > gaps.=0A> > > =0A> > > =0A> > > =0A> > > don't use to m uch. or you will get a wavy=0A> > structure. =0A> > > =0A> > > =0A> > > =0A > > > use type a for seams it helps with waves and type b=0A> > for=0A> > > fillets and fastener=0A> > > sealing=0A> > > =0A> > > =0A> > > =0A> > > do n't exceed the pot life =0A> > > =0A> > > =0A> > > =0A> > > mix it right an d use the correct proportions a good=0A> > scale=0A> > > really helps.=0A> > > =0A> > > =0A> > > =0A> > > use the longest pot life you can, i have fou nd that=0A> > 1/2=0A> > > stuff to be almost=0A> > > useless for most jobs. =0A> > > =0A> > > =0A> > > =0A> > > the proper place for sealant is on the inside of the=0A> > tank=0A> > > not globed on the=0A> > > outside beside i t looks ugly.=0A> > > =0A> > > =0A> > > =0A> > > tips of opening seams=0A> > > =0A> > > =0A> > > =0A> > > sharpend putty knives are great but be sure to round=0A> > the=0A> > > corners to help=0A> > > prevent gouges. take you r time here. gentle is better.=0A> > > =0A> > > =0A> > > =0A> > > removal o f sealant =0A> > > =0A> > > =0A> > > =0A> > > scotch bright disks work grea t. wear a mask. and=0A> > realodine=0A> > > after done.=0A> > > =0A> > > =0A> > > =0A> > > tank testing, quick easy and cheap=0A> > > =0A> > > =0A> > > =0A> > > connect air/nitrogen supply to vent =0A> > > =0A> > > connect clear hose to drain about ten feet worth=0A> > > =0A> > > loop hose to floo r and fill with water until you have=0A> > a=0A> > > loop with three feet =0A> > > high on both sides =0A> > > =0A> > > add nitrogen until the water is four feet higher on=0A> > one=0A> > > side then the other.=0A> > > you n ow have 2 psi in the tank. care should be taken=0A> > here,=0A> > > fill sl owly.=0A> > > =0A> > > spray the seams with soapy water and look for bubble s.=0A> > use=0A> > > hand soap or=0A> > > aircraft soap, some soaps are bad for alum.=0A> > > =0A> > > =0A> > > =0A> > > how to find that damn mystery leak i have tried=0A> > everything=0A> > > else.=0A> > > =0A> > > sometime s really small leaks are the worse to find,=0A> > but one=0A> > > way to tr ack=0A> > > them down is to apply dye-pen developer to the outside=0A> > of =0A> > > the tank it will=0A> > > show up any tiny leaks. over a couple of days.=0A> > > =0A> > > =0A> > > =0A> > > and this ends fuel tank 101 hope i t helps.=0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > rick miller =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A > > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > _____ =0A> > > =0A> > > =0A> > > Be a better fri end, newshound, and =0A> > > =0A> > > =0A> > > =0A> > > http://www.matronic s.com/contribution=0A> > > =0A> > > =0A> > > =0A> > >=0A> > t="_blank">http://www.matronics.com/Navigator?RV -List=0A> > > =0A> > > a>http: //forums.matronics.com=0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > =0A> > > _____ =0A> > > =0A> > > =0A> > > =0A> > > Be a better friend, newshound, and =0A> > > =0A> > > =0A> > > =0A> > > =0A> > =0A> > =0A> > =0A> > Be a better fri end, newshound, and =0A> > know-it-all with Yahoo! Mobile. Try it now. =0A> > http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ=0A> =0A> =0A> Be a better friend, newshound, and =0A> know-it-all with Yahoo! Mobile . Try it now.=0A> http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9t AcJ=0A=0A> =0A> =0A> =0A=0A=0A=0A________________________________=0A=0AGet Free (PRODUCT) RED=99 Emoticons, Winks and Display Pics. Check it out! =0A ====0A=0A=0A ___________________________________________________ _________________________________=0ABe a better friend, newshound, and =0Ak now-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt =Ahu06i62sR8HDtDypao8Wcj9tAcJ ________________________________ Message 9 _____________________________________ Time: 06:59:42 PM PST US From: David Cudney Subject: Re: RV-List: sniffle valve in RV 7A The sniffle valve I got from Superior with my engine sucks. Or more properly does not seal well under suction ( I can detect a slight leak when I check it by blowing backwards on it). I believe Dan Checkoway told me he replaced his with a better one but I lost my notes. Anyone have a sniffle valve source? Thanks dave On May 8, 2008, at 9:11 AM, SteinAir, Inc. wrote: > > Actually you can and will sometimes have fuel drain back down the > intake > tubes with an injected system. Prime it for a few seconds too long > and > it'll start dribbling, and sometimes on shutdown you can get a wee > bit as > well. It's standard practice to at least put a "weep hole" in the > FAB or > somewhere at the low point to make sure fuel doesn't pool where you > don't > want it. > > My 2 cents as usual. > > Cheers, > Stein > >> -----Original Message----- >> From: owner-rv-list-server@matronics.com >> [mailto:owner-rv-list-server@matronics.com]On Behalf Of James H >> Nelson >> Sent: Thursday, May 08, 2008 8:26 AM >> To: rv-list@matronics.com >> Subject: RV-List: sniffle valve in RV 7A >> >> >> >> I guess I am missing something. With fuel injection, you will not >> have >> fuel "dripping" down into the air box. The sniffle valve is >> necessary >> with a carburator style fuel system. With that system you can >> cause raw >> fuel to exceed the ability of the engine to ingest it. Especially >> if you >> have an accelertor pump on the carb. That will possibly let fuel >> run back >> into the air filter box. Am I in error? I have AFP system and it >> has >> the fuel purge system which will take off all fuel pressure in the >> shut >> down phase. During a starting phase the fuel is placed just in >> front of >> the intake valve and "should" all be ingested. >> >> Jim Nelson >> IO-360 >> >> >> >> > > ________________________________ Message 10 ____________________________________ Time: 07:38:24 PM PST US From: Fiveonepw@aol.com Subject: Re: RV-List: sniffle valve in RV 7A In a message dated 05/08/2008 8:33:29 AM Central Daylight Time, rv9jim@juno.com writes: I guess I am missing something. With fuel injection, you will not have fuel "dripping" down into the air box. The sniffle valve is necessary with a carburator style fuel system. With that system you can cause raw fuel to exceed the ability of the engine to ingest it. Especially if you have an accelertor pump on the carb. That will possibly let fuel run back into the air filter box. Am I in error? I have AFP system and it has the fuel purge system which will take off all fuel pressure in the shut down phase. During a starting phase the fuel is placed just in front of the intake valve and "should" all be ingested. >>> Yes, but only while the engine is cranking. When opened, the purge valve routes all fuel back to wherever it is plumbed, and prevents any from entering the engine via the spider when it is open, which is very useful to run cool fuel through the entire system with the boost pump on to help avoid vapor lock if the engine is hot. BUT- any time the boost pump is on (even is mixture control is at idle cut-off), "some" fuel is being discharged from the injectors. If not ingested by the cylinders by cranking the engine, it simply runs down the intake tubes into the "sump" (actually, the manifold under the oil sump) and will accumulate there. Hence the need to drain it via the sniffle valve. Careful control of the boost pump and purge valve will mitigate this drainage, but ultimately some fuel will wind up in the manifold. The AFP system will always "leak" fuel at the injectors if the purge valve is closed and there is fuel pressure, hence the need for the valve. This is one reason the purge valve is necessary, since pulling mixture to ICO will possibly not shut down a running engine as some fuel is still getting through the injectors. Opening the purge valve is the only way to completely shut all fuel flow off to the injectors. (Well, you could always shut off the fuel supply from the tanks or run them dry...) On a carbureted engine, pumping the throttle will definately shoot raw gas into the intake and if the engine is not cranking, this fuel would fall back into the air box, potentially creating a fire hazard. I never pump the throttle on my carbureted engine unless it is cranking for this very reason. Are you currently running your AFP equipped engine? If so, what is your start procedure, cold & hot? Mark **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________ Message 11 ____________________________________ Time: 08:19:20 PM PST US From: Fiveonepw@aol.com Subject: Re: RV-List: sniffle valve in RV 7A In a message dated 05/08/2008 9:01:55 PM Central Daylight Time, yenduc@sbcglobal.net writes: Or more properly does not seal well under suction ( I can detect a slight leak when I check it by blowing backwards on it). >>> I performed the same test on the valve I received in Vans FWF kit and it did the same as you describe. Concerned about this, I contacted tech support and was informed this was normal and the tiny amount of leakage would have no discernable effect. Consider the total amount of air consumed by the engine against the amount of air leaking past the valve. The engine (Aerosport IO-360) performed quite nicely with this valve installed both while engine running and while draining... Mark **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________ Message 12 ____________________________________ Time: 10:23:29 PM PST US From: "DEAN PSIROPOULOS" Subject: RV-List: Aviation Emissions >From AvWeb on the internet Thursday: Congress Scrutinizes Aviation Emissions The House Subcommittee on Aviation met on Tuesday for a hearing about aviation's impact on the environment. Noise and emissions from aviation are expected to double by 2025, the panel said, so aggressive action is needed soon to prevent that scenario. Gerald Dillingham, speaking for the U.S. Government Accountability Office, told the panel that NextGen developments will improve efficiency, but more funding is needed for research into better technology. National Air Transportation Association (NATA) President James Coyne also testified at the hearing. NetJets, a member of NATA, is investing in the development of an ultra-low-emissions jet fuel, Coyne said. Several representatives of the airline industry noted that given the cost of fuel, the industry is doing all it can to improve efficiency. Mary Ann Schaffer, of the Air Line Pilots Association, said pilots conserve fuel by various strategies, including single-engine taxiing, continuous descent arrivals, and flying at optimal altitudes and speeds. ---------------------------------------------------------------------------- This kind of stuff is going on EVERY day folks, if you are not concerned then you're not paying attention. Environmentalists and politicians would like to control every aspect of your life. Remember, private flying is just a frivolous and wasteful pursuit and it will be stopped(whether through moratoriums on fossil fuel burning to stop global warming, ultra-high gas prices or control freak politicians who need the environmentalist money and vote). If we the sane continue turn a blind eye to this we just as well cut up our airplanes for scrap metal. Politicians who had been braying about getting us independence from foreign oil were whining to OPEC last week to get production up to lower prices. US oil production has fallen by half in the last 20 years and the politicians have done nothing but put up more roadblocks to increasing domestic production. If you think they really want to help lower prices then you are naive. Dean N197DM Will fly if I have to distill the hydrocarbons myself ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv-list Browse Digests http://www.matronics.com/digest/rv-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.