---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Tue 05/06/08: 17 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:46 AM - Re: Proseal remover? (SCOTT SPENCER) 2. 06:57 AM - Re: Proseal remover? (RICHARD MILLER) 3. 08:37 AM - Re: Proseal remover? (Patrick Kelley) 4. 09:53 AM - Re: Crooks at Performance Engines (Jerry2DT@aol.com) 5. 11:16 AM - Re: Proseal remover? (jan) 6. 11:17 AM - Help Alternator stops working at 2000 agl (FASTPILOTRV8@AOL.COM) 7. 03:12 PM - Re: Proseal remover? (Larry Bowen) 8. 04:04 PM - Re: Proseal remover? (Charles Kuss) 9. 04:17 PM - Re: Proseal remover? (Charles Kuss) 10. 04:25 PM - Re: Proseal remover? (RICHARD MILLER) 11. 05:44 PM - digital true airspeed indicator (John Fasching) 12. 06:00 PM - Re: digital true airspeed indicator (Bruce Gray) 13. 06:22 PM - Re: digital true airspeed indicator (Jack Hilditch) 14. 07:06 PM - Carb replacement (Fiveonepw@aol.com) 15. 08:56 PM - Re: digital true airspeed indicator (Charles Reiche) 16. 09:27 PM - Re: digital true airspeed indicator (Paul Besing) 17. 10:16 PM - Re: digital true airspeed indicator (HCRV6@comcast.net) ________________________________ Message 1 _____________________________________ Time: 06:46:51 AM PST US From: SCOTT SPENCER Subject: Re: RV-List: Proseal remover? I remember hearing many years ago in A&P school that Proseal (890) has no known solvent. There are a number of things that will cause it to swell and soften it a little, MEK being one of them, but there is nothing that will melt it away. Sounds indeed like you made a small problem into a big one. I would pull the tank and remove the aft wall or cut holes in it and scrape out all the (now soft) proseal with a phenolic scraper, and then reseal the tank with a fresh batch. Then seal the aft wall in place again or seal covers on the holes. I had to reseal one of my tanks in the same way a number of years back, and chose to cut circular holes to work through and then made covers for them. Still holding. Scott RV-4 flying off and on since '92 ________________________________ Message 2 _____________________________________ Time: 06:57:21 AM PST US From: RICHARD MILLER 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 know-it-all with Yahoo! Mobile. Try it now. ________________________________ Message 3 _____________________________________ Time: 08:37:58 AM PST US From: "Patrick Kelley" Subject: RE: RV-List: Proseal remover? Domed nut plates? Van's doesn't supply those or call them out in the plans. I put a little fuel lube on the screws that hold the access plate on and I had no leaks when testing the tanks (except once when I forgot to tighten them down). Should I be concerned? Also, I'm getting to the point where I'll be hooking my fuel system to the engine. Airflow performance calls for purging the tanks and lines with fuel before doing this. What is the best way to do this? Will it hurt to use my electric pump to move the fuel, or will the filter be sufficient to protect it during the initial purge? Any replies, not just Richard's, will be appreciated. Patrick Kelley - RV-6A - Engine hung, beginning FWF process From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of RICHARD MILLER Sent: Tuesday, May 06, 2008 6:54 AM Subject: Re: RV-List: Proseal remover? Since we seem to have so many complaints about fuel leaks, lets cover fuel tank 101. *** stuff snipped *** types of leaks. *** more stuff snipped *** 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. *** remaining text snipped *** ________________________________ Message 4 _____________________________________ Time: 09:53:25 AM PST US From: Jerry2DT@aol.com Subject: RV-List: Re: Crooks at Performance Engines Just another lesson in sending large sums to small businesses before delivery of product. It is common that these small vendors use your money to stay afloat and then hope more $$$ comes in to fill your order. Of course this is a terrible business practice, and puts you and them at risk, but happens anyway. Using escrow is one answer, and if they refuse escrow, that tells you the story. One prominent builder has said online that he doesn't have a pile of money available if someone wants a deposit returned, because it's already spent... maybe on his salary... This is not to excuse in any way the practices of Performance Engines... My Two Bits, Jerry Cochran RV-6a N18XP In a message dated 5/6/2008 12:02:26 A.M. Pacific Daylight Time, rv-list@matronics.com writes: Subject: RV-List: Re: crooks at Performance Engines From: "steveadams" Sorry to hear about your situation. I had a similar situation (not aviation related) about 6 years ago. Went through all your going through, then went to court and won a $22,000 judgment. Unfortunately, a judgment against them means little to people like that. In all over 6 years I've received $3000 and been back to court 5 times. In my opinion, exposing him as you're doing and impacting his business is the best and probably the only way to really get his attention. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=181305#181305 **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________ Message 5 _____________________________________ Time: 11:16:36 AM PST US From: jan Subject: RE: RV-List: Proseal remover? 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 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

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
 
________________________________ Message 6 _____________________________________ Time: 11:17:09 AM PST US From: FASTPILOTRV8@AOL.COM Subject: RV-List: Help Alternator stops working at 2000 agl I have been plagued with the intermittent problems for over 6 months. At 1500 to 2000 ft AGL the alternator quits. Sometimes blows the 5 amp circuit breaker that goes to the field, sometimes it just quits. On the ground she works fine, even at 2200 RPM with a full load. On again off again with a full load , high speed taxi test. Yet, when I get in the air she quits at about 1500 AGL? I have a B&C Regulator model LR3C (older and has been repaired) and a B&C alternator plus there has been no technical help at B&C for the last two days (Tim quit and the boss is out of town) So has anyone had altermator problems and how did you fix it. I have replaced the battery behind rear baggage in my RV8 Replaced ground cable from the frame to the battery New bus bar with 1/4 studs from McMaster-Carr New heavier cable (Stein Air) from bus bar to B lead on alternator Removed 60 amp circuit breaker from system installed replaced with a firewall mounted DC 60 amp fuse All cables crimped and soldered at ring end only Glass panel from OP Technologies has no problem, CrossBow AHRS has no problem. Radios have no problem Help? any one have any ideas or experience with alternator gremlins Dane N838RV RV8a 378 hours **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________ Message 7 _____________________________________ Time: 03:12:36 PM PST US From: "Larry Bowen" Subject: Re: RV-List: Proseal remover? 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 you r > article with great interest. First =85 I have bought the domed nut plates =85 > they are used on commercial planes from what I understand =85 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 on e > to me =85 I thought cleaning with Aluprep =85rinse with water =85 and scu ff 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 fue l > 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 b e > 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 contaminate s? > 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 wil l > result in a crash, the unfortunate part of this is that the pilot is alwa ys > 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 lon g > 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 wh en > 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 t he > 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 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 wet helps to. > > > *sealant application tricks*. > > > clean /clean /clean. pro-seal dose not like oil and most primers but love s > 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 almos t > 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 wil l > 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* > > * * > > * > =========== nics.com/Navigator?RV-List =========== =========== com/contribution =========== > * > > ________________________________ Message 8 _____________________________________ Time: 04:04:16 PM PST US From: Charles Kuss Subject: RE: RV-List: Proseal remover? Jan Alodining the interior of the tank does 2 things. It gives you some measure of corrosion protection (since you can't prime the interior). Alodine also improves the grip of the ProSeal to the aluminum. Charlie Kuss --- On Tue, 5/6/08, jan wrote: > From: jan > Subject: RE: RV-List: Proseal remover? > To: rv-list@matronics.com > Date: Tuesday, May 6, 2008, 2:14 PM > 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 > > > > > Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ________________________________ Message 9 _____________________________________ Time: 04:17:23 PM PST US From: Charles Kuss Subject: RE: RV-List: Proseal remover? Pat, NAS 1473-A08 fuel tank nut plates are what almost all certified aircraft use. See http://www.wicksaircraft.com/catalog/product_cat.php/subid=2381/index.html I used them in my project on the recommendation of my local RV guru. That said, there are other ways of preventing the infamous RV fuel tank access cover leak. (Caused by fuel leaking between the common K1000 nutplates Vans provides and the threads of the attaching screws. Some builders substitute goops of ProSeal for the supplied cork gasket. This works, but can make future removal of the access cover a hassle. Other builders purchase special #8 pan head machine screws from vendors like MSC or McMaster-Carr. These special screws have a groove for a sealing O-ring under the head of the screw. If you go this route, be sure to specify that you want VITON O-rings with the screws. (The standard Silicone O-rings won't hold up to either 100LL or auto fuels). These screws are cheaper than the NAS 1473 nutplates and work well on tanks which have already been built using the supplied K1000 screws. Using either the NAS 1473 nutplates or special screws, allows you to use the supplied cork gaskets with no leaks and easy future removal of your access covers. Choose which method you want to use and blaze on! Charlie Kuss PS Unlike Larry, I had no interference problems between my NAS 1473 nutplates and my fuel pick ups. If you want, I can supply photos of what the NAS 1473 nutplates look like when installed. Contact me directly, if interested --- On Tue, 5/6/08, Patrick Kelley wrote: > From: Patrick Kelley > Subject: RE: RV-List: Proseal remover? > To: rv-list@matronics.com > Date: Tuesday, May 6, 2008, 11:33 AM > Domed nut plates? Van's doesn't supply those or > call them out in the plans. > I put a little fuel lube on the screws that hold the access > plate on and I > had no leaks when testing the tanks (except once when I > forgot to tighten > them down). Should I be concerned? > > > > Also, I'm getting to the point where I'll be > hooking my fuel system to the > engine. Airflow performance calls for purging the tanks > and lines with fuel > before doing this. What is the best way to do this? Will > it hurt to use my > electric pump to move the fuel, or will the filter be > sufficient to protect > it during the initial purge? Any replies, not just > Richard's, will be > appreciated. > > > > Patrick Kelley - RV-6A - Engine hung, beginning FWF process > > > > From: owner-rv-list-server@matronics.com > [mailto:owner-rv-list-server@matronics.com] On Behalf Of > RICHARD MILLER > Sent: Tuesday, May 06, 2008 6:54 AM > 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. > > > > *** stuff snipped *** > > > > types of leaks. > > > > *** more stuff snipped *** > > > > 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. > > > > *** remaining text snipped *** Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ________________________________ Message 10 ____________________________________ Time: 04:25:00 PM PST US From: RICHARD MILLER 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 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 _blank">http://www.matronics.com/contribution --------------------------------- Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. ________________________________ Message 11 ____________________________________ Time: 05:44:03 PM PST US From: "John Fasching" Subject: RV-List: digital true airspeed indicator Does anyone know a source for a digital true airspeed indicator? I want a stand-alone meter, not a TAS that a part of a 'glass cockpit' type system. thanks for a clue. John ________________________________ Message 12 ____________________________________ Time: 06:00:10 PM PST US From: "Bruce Gray" Subject: RE: RV-List: digital true airspeed indicator Rocky Mountian Instruments Micro Encoder. Bruce www.Glasair.org -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of John Fasching Sent: Tuesday, May 06, 2008 8:41 PM Subject: RV-List: digital true airspeed indicator Does anyone know a source for a digital true airspeed indicator? I want a stand-alone meter, not a TAS that a part of a 'glass cockpit' type system. thanks for a clue. John ________________________________ Message 13 ____________________________________ Time: 06:22:50 PM PST US From: "Jack Hilditch" Subject: RE: RV-List: digital true airspeed indicator Try these. http://www.lightflying.com.au/Stratomaster%20Pages/Smart%20Singles.htm Jack _____ From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of John Fasching Sent: Tuesday, May 06, 2008 8:41 PM Subject: RV-List: digital true airspeed indicator Does anyone know a source for a digital true airspeed indicator? I want a stand-alone meter, not a TAS that a part of a 'glass cockpit' type system. thanks for a clue. John ________________________________ Message 14 ____________________________________ Time: 07:06:27 PM PST US From: Fiveonepw@aol.com Subject: RV-List: Carb replacement Howdy all- Time to replace Mojos carb- she's presently sporting a Marvel-Schebler MA-4SPA, pn 10-5009, and it has worn to the point that idle cutoff isn't. I also suspect there may be other difficulties since I'm seeing uncharacteristically high EGTs, and enrichening seems to offer little remedy. I know there has been some turmoil of late in the world of carburetors, but can anyone offer a rock-solid source for a rebuilt replacement for this item? Thanks From The PossumWorks in TN Mark - do not archive _http://websites.expercraft.com/n51pw/_ (http://websites.expercraft.com/n51pw/) **************Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. (http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001) ________________________________ Message 15 ____________________________________ Time: 08:56:02 PM PST US From: "Charles Reiche" Subject: Re: RV-List: digital true airspeed indicator Insight TAS 1000 ----- Original Message ----- From: John Fasching To: rv-list@matronics.com Sent: Tuesday, May 06, 2008 8:40 PM Subject: RV-List: digital true airspeed indicator Does anyone know a source for a digital true airspeed indicator? I want a stand-alone meter, not a TAS that a part of a 'glass cockpit' type system. thanks for a clue. John ________________________________ Message 16 ____________________________________ Time: 09:27:51 PM PST US From: Paul Besing Subject: Re: RV-List: digital true airspeed indicator The micro encoder is the coolest thing I have ever had. I have had two of them now. I just had my new pitot static certification done, and the guys at the avionics shop were shocked at how it's calibration is perfect after two years. He said "We don't have King Air's that are this accurate" and "I can't get this thing to fail" Keeps pluggin along and accurate within 5 feet...oh yeah, not to hijack the thread, but it has digital True Airspeed.. Paul Besing ----- Original Message ---- From: Bruce Gray Sent: Tuesday, May 6, 2008 5:57:02 PM Subject: RE: RV-List: digital true airspeed indicator Message Rocky Mountian Instruments Micro Encoder. Bruce www.Glasair.org -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of John Fasching Sent: Tuesday, May 06, 2008 8:41 PM Subject: RV-List: digital true airspeed indicator Does anyone know a source for a digital true airspeed indicator? I want a stand-alone meter, not a TAS that a part of a 'glass cockpit' type system. thanks for a clue. John href="http://www.matronics.com/Navigator?RV-List">http://www.matronics.com/Navigator?RV-List Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ________________________________ Message 17 ____________________________________ Time: 10:16:56 PM PST US From: HCRV6@comcast.net Subject: Re: RV-List: digital true airspeed indicator ------------------------------------------------------------------------------------- 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.