---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 05/18/12: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:13 AM - Re: Anti Corrosive Zinc Paste (John MacCallum) 2. 05:09 AM - Re: Anti Corrosive Zinc Paste (ROGER & JEAN CURTIS) 3. 06:11 AM - Re: Anti Corrosive Zinc Paste (Eric M. Jones) 4. 06:58 AM - Re: Re: Ignition Interference (Richard Girard) 5. 10:49 AM - Re: Anti-corrosive paste (D L Josephson) 6. 11:05 AM - Re: Re: Anti-corrosive paste (Mike Wynn) 7. 12:22 PM - Re: Re: Anti-corrosive paste (Bill) 8. 01:19 PM - Re: Re: Anti-corrosive paste () 9. 04:37 PM - Re: Re: Anti Corrosive Zinc Paste (Henador Titzoff) 10. 04:45 PM - Re: Re: Anti-corrosive paste (Henador Titzoff) ________________________________ Message 1 _____________________________________ Time: 12:13:52 AM PST US From: "John MacCallum" Subject: RE: AeroElectric-List: Anti Corrosive Zinc Paste I used Penetrox on a 9El Log Periodic for 13-29 mhz and also on 2 x 13 EL Long Boom 2m Yagis. Up in the Air for about 5 years. The joints out lasted the feedlines after the White Cockatoos got them L Cheers John MacCallum RV10 41016 VH-DUU From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob McCallum Sent: Friday, 18 May 2012 9:00 AM Subject: RE: AeroElectric-List: Anti Corrosive Zinc Paste Henador; Bear in mind that both of the proprietary products you mention are specifically manufactured for preventing the corrosion of Aluminium wiring connections so they should be particularly effective at keeping oxygen out of the joint. When making crimped connections on Aluminium Hydro transmission lines the process was to strip the insulation, brush the conductors bright with a stainless steel brush, dip the wire into the pot of Penetrox, and then install the connector with a hydraulic crimper. Never heard of a failure of any joints done this way even in the rather harsh environment of the mining industry. Bob McC _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Henador Titzoff Sent: Thursday, May 17, 2012 3:01 PM Subject: AeroElectric-List: Anti Corrosive Zinc Paste Hi People, I would like to know what opinions you have on anti-corrosive zinc paste to make our connections more reliable. Below is a link to an article on how ACZP helps make better connections by supplying sacrificial zinc ions to stop or decrease corrosion at the push on connector's mechanical linkage, which actually supplies the electrical connection. The two pastes he mentions, Burndy Penetrox and Ideal Noalox, seem to do the job but are either too far on the right or left when it comes to consistency. Do you guys think that ACZP will help with our normal push on connectors that we use in aviation, and/or do you have a product recommendation that is better than these two products? I do have an application to wire lights on a large road trailor, and I would like to use ACZP on those connections, since road surfaces can be covered with all sorts of nasty corrosive substances. Perhaps a ACZP can have a good application there to keep out all the nasties. What do you guys think? Eric, you're pretty good on surfaces corroding. What do you think? You, too, Bob. http://sw-em.com/anti_corrosive_paste.htm Thanks. Henador Titzoff http://www.matronics.com/Navigator?AeroElectric-List http://forums.matronics.com http://www.matronics.com/contribution ________________________________ Message 2 _____________________________________ Time: 05:09:37 AM PST US From: "ROGER & JEAN CURTIS" Subject: RE: AeroElectric-List: Anti Corrosive Zinc Paste The joints out lasted the feedlines after the White Cockatoos got them L Over the years I have lost a lot of sleep, wondering if the Cockatoos, especially The White ones, were eating my radio antenna feed lines. So far I have seen no Signs of damage from the critters, but I will continue to be vigilant and keep My aircraft locked at all times to be safe. =98=BA =98=BA =98=BA Roger Do Not Archive ________________________________ Message 3 _____________________________________ Time: 06:11:12 AM PST US Subject: AeroElectric-List: Re: Anti Corrosive Zinc Paste From: "Eric M. Jones" Henador; As Bob and others have said, ACZP, which is probably zinc oxide + silicone grease, has the merits of keeping environmentals out of the joint while also transferring heat. The glop used to stick your microprocessor to its heat sink is usually zinc oxide/silicone grease. Many substances make good electrical joint sealant, and yes, putting insulating grease on a conductive joint makes perfect sense, since the grease only replaces existing insulating air gaps. Sometimes people use silver paste, but not because it's electrically conductive--silver is a better heat conductor. Why any notion of zinc being "sacrificial" comes up is beyond me. You certainly wouldn't want to use it if it was. The only reason not to use it is that it is messy. Otherwise it would be everywhere. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=373289#373289 ________________________________ Message 4 _____________________________________ Time: 06:58:55 AM PST US Subject: Re: AeroElectric-List: Re: Ignition Interference From: Richard Girard If " When a handheld is swapped out for the V6, it does just fine" means that it doesn't repeat any of the faults of the MGL radio, get an RA number and send the MGL back to the manufacturer to have it fixed or replaced. Rick Girard On Thu, May 17, 2012 at 8:46 PM, messydeer wrote: > > My SWR's all came in less than 2.1, thank Gawd! But wait, there's more. > Here's what I posted on the MGL forum: > > While trying to sort out my ignition noise issues, I had some odd things > happen with my V6. > > To isolate everything I could, the only wires connected to the V6 are the > 4 audio jacks (which are for sure isolated from the panel), the ground > (goes directly to the negative of a separate battery ), the supply > (separate battery), and the antenna on top of the tailcone. > > The V6 is located in the middle of my Sonex panel, ~2' off the floor, 2' > behind the firewall. I turn it on and get good reception. Start the engine > and the reception vanishes. I can't even get the blasted ignition noise. > Rebooting the V6 with the engine running doesn't do anything. Kill the > engine and there's still no reception. Adjusting the squelch does nothing. > And this is with the engine turned off after having run for a minute. The > only thing that lets the V6 get reception again is to reboot it AFTER the > engine is off. > > The antenna, when installed, did not have a ground fault. When a handheld > is swapped out for the V6, it does just fine. Even if the antenna had a > ground fault to the airframe, could that cause the V6 to lose reception? > There's no ground route back to the V6. If so, then why doesn't the > handheld behave the same way when it is connected to the same antenna? It > works just fine with the same cable and antenna. > > Next time I'm at the airport, I'll connect a portable antenna to make sure > there's no ground problem. Any other suggestions? > > -------- > Dan > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=373257#373257 > > -- Zulu Delta Mk IIIC Thanks, Homer GBYM It isn't necessary to have relatives in Kansas City in order to be unhappy. - Groucho Marx ________________________________ Message 5 _____________________________________ Time: 10:49:52 AM PST US From: D L Josephson Subject: AeroElectric-List: Re: Anti-corrosive paste On 5/17/12 11:57 PM, AeroElectric-List Digest Server wrote: > Hi People,=0A=0AI would like to know what opinions you have on > anti-corrosi ve zinc paste to make our connections more reliable. > -Below is a link to an article on how ACZP helps make better > connections by Bob has explained thoroughly about what's happening here. Let's go a few steps further. The idea is to make the metal-to-metal contact area of the conductors as large as possible by forming them into each other, and to exclude any contaminants that might get between the metals. Any nonconductive contaminant reduces the size of the contact area, which increases the resistance. Most troublesome are oxides and salts of the metals, which occur when air, water and other chemicals eventually convert the metal to something else, producing a barrier between the two parts. Zinc chromate paste excludes water to some extent but its main function is to combine chemically with *aluminum* to produce a thin chemical film that is conductive, and to prevent the formation of aluminum oxides which are not. I don't know whether any such reaction occurs with copper, I haven't seen "ACZP" used for this purpose. The idea of using a grease like silicone (DC4) is based entirely on excluding air and water. Silicone grease is used on microwave and RF connections because it doesn't badly compromise the dielectric constant of insulators it gets on. But for DC, any ordinary grease will do; it also lubricates the parts as they are being crushed by the wrench or crimper, so they can conform to each other's surfaces more readily. The very best grease for this purpose has been used for nearly 100 years for all kinds of high current applications by the telephone company, but it seems to be a secret in the light aviation industry. I first learned of it at a helicopter battery shop where they made their own version, with a little more solvent added so it could be painted on. It's cheap and readily available. It's a combination of petroleum grease, some waxes to make it stiff and some amines to make it penetrate into joints and spread throughout the voids in the contact over time. It is closely related to "cosmoline" and is called No-Ox-Id "A Special" made since the early 1910s by Sanchem in Chicago. A big tube of it sells on eBay for about $10 but you can buy cases of 24 at less than $5 apiece. You can see the various other versions of No-Ox-Id on their site. A-Special is thinned out a little so it can be squeezed out of a tube (if the tube is a little warm.) You only need a very thin film but you can coat all the metal parts with this, clamp them together and you're done. I have taken apart telephone company installations more than 50 years old that had this stuff in all their joints and there has never been any corrosion. Many fleet operators use it on battery posts and terminals to keep the lead from corroding, you can even massage it into the joint between the post and the battery case to slow down the battery acid vapors from getting to the post that way. I started using it on aircraft and automotive things about 30 years ago and it just works. -- David Josephson ________________________________ Message 6 _____________________________________ Time: 11:05:52 AM PST US From: "Mike Wynn" Subject: Re: AeroElectric-List: Re: Anti-corrosive paste Thanks for an extremely helpful reply on the subject of pastes. It's time to add another goody to the tool box! M. Wynn/A&P, LNC2 bld'r. ********* ----- Original Message ----- From: "D L Josephson" Sent: Friday, May 18, 2012 11:45 AM Subject: AeroElectric-List: Re: Anti-corrosive paste > > > On 5/17/12 11:57 PM, AeroElectric-List Digest Server wrote: >> Hi People,=0A=0AI would like to know what opinions you have on >> anti-corrosi ve zinc paste to make our connections more reliable. -Below >> is a link to an article on how ACZP helps make better connections by > Bob has explained thoroughly about what's happening here. Let's go a few > steps further. The idea is to make the metal-to-metal contact area of the > conductors as large as possible by forming them into each other, and to > exclude any contaminants that might get between the metals. Any > nonconductive contaminant reduces the size of the contact area, which > increases the resistance. Most troublesome are oxides and salts of the > metals, which occur when air, water and other chemicals eventually convert > the metal to something else, producing a barrier between the two parts. > Zinc chromate paste excludes water to some extent but its main function is > to combine chemically with *aluminum* to produce a thin chemical film that > is conductive, and to prevent the formation of aluminum oxides which are > not. I don't know whether any such reaction occurs with copper, I haven't > seen "ACZP" used for this purpose. > > The idea of using a grease like silicone (DC4) is based entirely on > excluding air and water. Silicone grease is used on microwave and RF > connections because it doesn't badly compromise the dielectric constant of > insulators it gets on. But for DC, any ordinary grease will do; it also > lubricates the parts as they are being crushed by the wrench or crimper, > so they can conform to each other's surfaces more readily. The very best > grease for this purpose has been used for nearly 100 years for all kinds > of high current applications by the telephone company, but it seems to be > a secret in the light aviation industry. I first learned of it at a > helicopter battery shop where they made their own version, with a little > more solvent added so it could be painted on. It's cheap and readily > available. It's a combination of petroleum grease, some waxes to make it > stiff and some amines to make it penetrate into joints and spread > throughout the voids in the contact over time. It is closely related to > "cosmoline" and is called No-Ox-Id "A Special" made since the early 1910s > by Sanchem in Chicago. A big tube of it sells on eBay for about $10 but > you can buy cases of 24 at less than $5 apiece. You can see the various > other versions of No-Ox-Id on their site. A-Special is thinned out a > little so it can be squeezed out of a tube (if the tube is a little warm.) > You only need a very thin film but you can coat all the metal parts with > this, clamp them together and you're done. > > I have taken apart telephone company installations more than 50 years old > that had this stuff in all their joints and there has never been any > corrosion. Many fleet operators use it on battery posts and terminals to > keep the lead from corroding, you can even massage it into the joint > between the post and the battery case to slow down the battery acid vapors > from getting to the post that way. I started using it on aircraft and > automotive things about 30 years ago and it just works. > > -- > David Josephson > > > ________________________________ Message 7 _____________________________________ Time: 12:22:44 PM PST US Subject: Re: AeroElectric-List: Re: Anti-corrosive paste From: Bill Hi David - This sounds similar in application to Par-Al-Ketone - used on aircraft flight and engine control cables. Do you know of this product, and is it similar No-Ox-Id? See Wick's offering below: http://www.wicksaircraft.com/catalog/product_cat.php/subid=10183/index.html Bill SF bay area On Fri, May 18, 2012 at 10:45 AM, D L Josephson wrote: > dlj04@josephson.com> > > On 5/17/12 11:57 PM, AeroElectric-List Digest Server wrote: > >> Hi People,=0A=0AI would like to know what opinions you have on >> anti-corrosi ve zinc paste to make our connections more reliable. -Below is >> a link to an article on how ACZP helps make better connections by >> > Bob has explained thoroughly about what's happening here. Let's go a few > steps further. The idea is to make the metal-to-metal contact area of the > conductors as large as possible by forming them into each other, and to > exclude any contaminants that might get between the metals. Any > nonconductive contaminant reduces the size of the contact area, which > increases the resistance. Most troublesome are oxides and salts of the > metals, which occur when air, water and other chemicals eventually convert > the metal to something else, producing a barrier between the two parts. > Zinc chromate paste excludes water to some extent but its main function is > to combine chemically with *aluminum* to produce a thin chemical film that > is conductive, and to prevent the formation of aluminum oxides which are > not. I don't know whether any such reaction occurs with copper, I haven't > seen "ACZP" used for this purpose. > > The idea of using a grease like silicone (DC4) is based entirely on > excluding air and water. Silicone grease is used on microwave and RF > connections because it doesn't badly compromise the dielectric constant of > insulators it gets on. But for DC, any ordinary grease will do; it also > lubricates the parts as they are being crushed by the wrench or crimper, so > they can conform to each other's surfaces more readily. The very best > grease for this purpose has been used for nearly 100 years for all kinds of > high current applications by the telephone company, but it seems to be a > secret in the light aviation industry. I first learned of it at a > helicopter battery shop where they made their own version, with a little > more solvent added so it could be painted on. It's cheap and readily > available. It's a combination of petroleum grease, some waxes to make it > stiff and some amines to make it penetrate into joints and spread > throughout the voids in the contact over time. It is closely related to > "cosmoline" and is called No-Ox-Id "A Special" made since the early 1910s > by Sanchem in Chicago. A big tube of it sells on eBay for about $10 but you > can buy cases of 24 at less than $5 apiece. You can see the various other > versions of No-Ox-Id on their site. A-Special is thinned out a little so it > can be squeezed out of a tube (if the tube is a little warm.) You only need > a very thin film but you can coat all the metal parts with this, clamp them > together and you're done. > > I have taken apart telephone company installations more than 50 years old > that had this stuff in all their joints and there has never been any > corrosion. Many fleet operators use it on battery posts and terminals to > keep the lead from corroding, you can even massage it into the joint > between the post and the battery case to slow down the battery acid vapors > from getting to the post that way. I started using it on aircraft and > automotive things about 30 years ago and it just works. > > -- > David Josephson > > ________________________________ Message 8 _____________________________________ Time: 01:19:37 PM PST US From: Subject: RE: AeroElectric-List: Re: Anti-corrosive paste Isn't that how they market dialectic grease available for $2 at Home Depot? That will likely work for the electrical parts you can access which means the electrical parts will outlast the rest of the airplane - for the body you simply take out all of the rivets between the non-compatible parts and puts some grease in there and rivet them back together. Good luck inside the wings. When your AP tells you your wing is rotting inside out from the same problem, have a check ready. Oh, and you do realize on older airplanes the wire covering will rot and short out only while you are flying at night before the connectors oxidize. When the skin comes off that big breaker wire in the panel on the old jobs, it's a real light show. I'm sticking with carbon/fiberglass for the body. When I'm gone the wife can use it as a lawn ornament. The Buss panels you buy from B&C will probably last longer than you own your airplane. If not, they are < $20 to replace. If you smoke and would buy electrical parts each day instead of cigarettes, you could replace all the parts every weekend :) They also sell a kit that will charge - ions with + 1's to stave the rust advance - I've no idea if that swamp land idea works. Since many folks use some kind of battery tender anyway you can run a cord with a 25 watt bulb attached and hang it in your avionics bay. Cheapest insurance available. Of course you can also move to Arizona and just park in the field under an umbrella. Be sure to disconnect the light bulb before you fly away. Have a great weekend everybody, Glenn -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill Sent: Friday, May 18, 2012 3:18 PM Subject: Re: AeroElectric-List: Re: Anti-corrosive paste Hi David - This sounds similar in application to Par-Al-Ketone - used on aircraft flight and engine control cables. Do you know of this product, and is it similar No-Ox-Id? See Wick's offering below: http://www.wicksaircraft.com/catalog/product_cat.php/subid=10183/index.html Bill SF bay area On Fri, May 18, 2012 at 10:45 AM, D L Josephson wrote: > dlj04@josephson.com> > > On 5/17/12 11:57 PM, AeroElectric-List Digest Server wrote: > >> Hi People,=0A=0AI would like to know what opinions you have on >> anti-corrosi ve zinc paste to make our connections more reliable. >> -Below is a link to an article on how ACZP helps make better >> connections by >> > Bob has explained thoroughly about what's happening here. Let's go a > few steps further. The idea is to make the metal-to-metal contact area > of the conductors as large as possible by forming them into each > other, and to exclude any contaminants that might get between the > metals. Any nonconductive contaminant reduces the size of the contact > area, which increases the resistance. Most troublesome are oxides and > salts of the metals, which occur when air, water and other chemicals > eventually convert the metal to something else, producing a barrier between the two parts. > Zinc chromate paste excludes water to some extent but its main > function is to combine chemically with *aluminum* to produce a thin > chemical film that is conductive, and to prevent the formation of > aluminum oxides which are not. I don't know whether any such reaction > occurs with copper, I haven't seen "ACZP" used for this purpose. > > The idea of using a grease like silicone (DC4) is based entirely on > excluding air and water. Silicone grease is used on microwave and RF > connections because it doesn't badly compromise the dielectric > constant of insulators it gets on. But for DC, any ordinary grease > will do; it also lubricates the parts as they are being crushed by the > wrench or crimper, so they can conform to each other's surfaces more > readily. The very best grease for this purpose has been used for > nearly 100 years for all kinds of high current applications by the > telephone company, but it seems to be a secret in the light aviation > industry. I first learned of it at a helicopter battery shop where > they made their own version, with a little more solvent added so it > could be painted on. It's cheap and readily available. It's a > combination of petroleum grease, some waxes to make it stiff and some > amines to make it penetrate into joints and spread throughout the > voids in the contact over time. It is closely related to "cosmoline" > and is called No-Ox-Id "A Special" made since the early 1910s by > Sanchem in Chicago. A big tube of it sells on eBay for about $10 but > you can buy cases of 24 at less than $5 apiece. You can see the > various other versions of No-Ox-Id on their site. A-Special is thinned > out a little so it can be squeezed out of a tube (if the tube is a > little warm.) You only need a very thin film but you can coat all the metal parts with this, clamp them together and you're done. > > I have taken apart telephone company installations more than 50 years > old that had this stuff in all their joints and there has never been > any corrosion. Many fleet operators use it on battery posts and > terminals to keep the lead from corroding, you can even massage it > into the joint between the post and the battery case to slow down the > battery acid vapors from getting to the post that way. I started using > it on aircraft and automotive things about 30 years ago and it just works. > > -- > David Josephson > > ________________________________ Message 9 _____________________________________ Time: 04:37:49 PM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Re: Anti Corrosive Zinc Paste Thank you for weighing in, Eric.- When attaching connectors to wires in =0Aavionics and automotive applications, there isn't a need for increasing =0Aheat transfer, so zinc is not needed.- A simple dielectric grease is =0Asufficient, you say.- This is pretty much what Bob says, so I'll run =0Awith it.=0A=0AThere are several posts from people about this, and I see two more that I=0A haven't read.- Let me see what they say and hopefully one of them will stand out on a recommended good grease at a good price and readily available.=0A=0AThanks,=0A=0A-=0AHenador Titzoff=0A=0A=0A_______ _________________________=0A From: Eric M. Jones =0ATo : aeroelectric-list@matronics.com =0ASent: Friday, May 18, 2012 9:07 AM=0AS ubject: AeroElectric-List: Re: Anti Corrosive Zinc Paste=0A =0A--> AeroElec tric-List message posted by: "Eric M. Jones" =0A=0AHen ador; =0A=0AAs Bob and others have said, ACZP, which is probably zinc oxide nt while also transferring heat. The glop used to stick your microprocessor to its heat sink is usually zinc oxide/silicone grease.=0A=0AMany substanc es make good electrical joint sealant, and yes, putting insulating grease o n a conductive joint makes perfect sense, since the grease only replaces ex isting insulating air gaps. Sometimes people use silver paste, but not beca use it's electrically conductive--silver is a better heat conductor.=0A=0AW hy any notion of zinc being "sacrificial" comes up is beyond me. You certai nly wouldn't want to use it if it was. =0A=0AThe only reason not to use it is that it is messy. Otherwise it would be everywhere.=0A=0A--------=0AEric M. Jones=0Awww.PerihelionDesign.com=0A113 Brentwood Drive=0ASouthbridge, M A 01550=0A(508) 764-2072=0Aemjones(at)charter.net=0A=0A=0A=0A=0ARead this t opic online here:=0A=0Ahttp://forums.matronics.com/viewtopic.php?p=373289 == ________________________________ Message 10 ____________________________________ Time: 04:45:24 PM PST US From: Henador Titzoff Subject: Re: AeroElectric-List: Re: Anti-corrosive paste Dave,=0A=0AAs Mike says below, thanks for an extremely helpful reply on the subject of pastes. -I'm gonna look for a tube of No-Ox-Id A Special to s ee what it is like. -I'm going to compare it to the Permatex stuff one ca n get at AutoZone to see which one I like better, as both are probably very good for this application.=0A=0AThanks, everyone.=0AHenador Titzoff=0A=0A =0A________________________________=0A From: Mike Wynn =0ATo: aeroelectric-list@matronics.com =0ASent: Friday, May 18, 2012 2:02 PM=0ASubject: Re: AeroElectric-List: Re: Anti-corrosive paste=0A =0A--> Aer oElectric-List message posted by: "Mike Wynn" =0A=0ATh anks for an extremely helpful reply on the subject of pastes.=0AIt's time t o add another goody to the tool box!=0AM. Wynn/A&P, LNC2 bld'r.=0A********* =0A----- Original Message ----- From: "D L Josephson" =0ATo: =0ASent: Friday, May 18, 2012 11:45 AM=0ASubject: AeroElectric-List: Re: Anti-corrosive paste=0A=0A=0A> --> Ae roElectric-List message posted by: D L Josephson =0A> =0A> On 5/17/12 11:57 PM, AeroElectric-List Digest Server wrote:=0A>> Hi Pe ople,=0A=0AI would like to know what opinions you have on anti-corrosi ve zinc paste to make our connections more reliable. -Below is a link to an article on how ACZP helps make better connections by=0A> Bob- has explai ned thoroughly about what's happening here. Let's go a few steps further. T he idea is to make the metal-to-metal contact area of the conductors as lar ge as possible by forming them into each other, and to exclude any contamin ants that might get between the metals. Any nonconductive contaminant reduc es the size of the contact area, which increases the resistance. Most troub lesome are oxides and salts of the metals, which occur when air, water and other chemicals eventually convert the metal to something else, producing a barrier between the two parts. Zinc chromate paste excludes water to some extent but its main function is to combine chemically with *aluminum* to pr oduce a thin chemical film that is conductive, and to prevent the formation of aluminum oxides which are not. I don't know whether any such reaction o ccurs with copper, I haven't seen "ACZP" used for this purpose.=0A> =0A> Th e idea of using a grease like silicone (DC4) is based entirely on excluding air and water. Silicone grease is used on microwave and RF connections bec ause it doesn't badly compromise the dielectric constant of insulators it g ets on. But for DC, any ordinary grease will do; it also lubricates the par ts as they are being crushed by the wrench or crimper, so they can conform to each other's surfaces more readily. The very best grease for this purpos e has been used for nearly 100 years for all kinds of high current applicat ions by the telephone company, but it seems to be a secret in the light avi ation industry. I first learned of it at a helicopter battery shop where th ey made their own version, with a little more solvent added so it could be painted on. It's cheap and readily available. It's a combination of petrole um grease, some waxes to make it stiff and some amines to make it penetrate into joints and spread throughout the voids in the contact over time. It is closely related to "cosmoline" and is called No-Ox-Id "A Speci al" made since the early 1910s by Sanchem in Chicago. A big tube of it sell s on eBay for about $10 but you can buy cases of 24 at less than $5 apiece. You can see the various other versions of No-Ox-Id on their site. A-Specia l is thinned out a little so it can be squeezed out of a tube (if the tube is a little warm.) You only need a very thin film but you can coat all the metal parts with this, clamp them together and you're done.=0A> =0A> I have taken apart telephone company installations more than 50 years old that ha d this stuff in all their joints and there has never been any corrosion. Ma ny fleet operators use it on battery posts and terminals to keep the lead f rom corroding, you can even massage it into the joint between the post and the battery case to slow down the battery acid vapors from getting to the p ost that way. I started using it on aircraft and automotive things about 30 years ago and it just works.=0A> =0A> --=0A> David Josephson=0A> =0A> =0A> ====================== ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-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/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-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.