Tip: Proseal ...The fact and the fiction

[smiller]

This is one thing (setting wet rivets) where a helper can make a HUGE difference: two hands holding/stabilizing the rivet gun and two hands holding/stabilizing the bucking bar. I also second the comment about the air pressure. Too low and you work-harden the rivet, but too high and you have control problems (esp. if solo).

I remember the tanks being very messy work, and making liberal use of shop towels, lint-free rags, and MEK to keep the tools (and everything else!) clean.

[bddalm]

Scott,
If you put a generous coat of proseal on the ribs before you cleco them to the fuel tank skin, there should be no reason to put proseal on each individual rivet. After all my ribs were finally in, I added an additional layer of proseal on the buck tails. I agree that a tungsten bucking bar works best. I prefer old cotton t-shirts though as shop rags tend to leave too much lint behind.

[N941WR]

Originally Posted by smiller

...I remember the tanks being very messy work, and making liberal use of shop towels, lint-free rags, and MEK to keep the tools (and everything else!) clean.

One thing, and this is very important, DO NOT clean up the tanks or rivets with MEK!

It is best to let the tanks dry and then sand the excess MEK off the tank.

I flew for two years before having my plane painted. Before going to the painters, I cleaned the excess proseal off the top of the left tank with MEK. A year after it was painted I had the dreaded paint blisters but only on the top of the left tank, where I had used MEK to clean it up.

Do use MEK to clean up the tools and clecos, that won't be a problem.

[sblack]

Originally Posted by bddalm

Scott,
If you put a generous coat of proseal on the ribs before you cleco them to the fuel tank skin, there should be no reason to put proseal on each individual rivet. After all my ribs were finally in, I added an additional layer of proseal on the buck tails. I agree that a tungsten bucking bar works best. I prefer old cotton t-shirts though as shop rags tend to leave too much lint behind.

There seem to be conflicting opinions on this. I agree that if you have a perfect coating there should be no path from the edge of the rib to coming out the dimple, in a perfect world. I guess it is a belt and braces thing. I have talked to professionals at AC mfgs and they put sealant on the rivets in the hole before shooting them according to their published milspec type processes. I think my biggest problem is that I am not very good at riveting in general, having bought an almost structurally complete project. But I am learning. Thanks for your input.

[bddalm]

Bill R,
Just wondering, do you have quick build wings?

[sblack]

I am trying to remove sealant from the tails of some rivets because i don't think I inspected them carefully enough. I bought poly-gone 310 gel, thinking it would just dissolve it away but I found it not to be that effective. I had to reapply it so often I used up a $40 jar and still didn't get everything done. It seems to only dissolve the top few thou of material. Is there a trick to using that stuff? Also, do the urethane sealant cutters work well? Are they a better bet to clean things off quickly? Any wisdom appreciated.

[MNAv8or]

[quote=N941WR;959766]One thing, and this is very important, DO NOT clean up the tanks or rivets with MEK! QUOTE]


MEK is one of the best cleaners to use for pro seal. If you read whats in proseal, some of the Mil spec sealants have MEK in them! I work on aircraft for a living and use only MEK to clean metal before proseal application and for clean up and I have never had paint issues with the use of MEK. We actually add MEK to proseal in some instances because it will help thin out the sealant to flow a lot better and it will extend the working time if need be. In over 10 years of resealing windshields, Mooney fuel tanks, and numerous other pro seal adventures, I have never had MEK bubble paint.

SBlack - In my experience Poly-gone does not work the best on certain sealants. The only sealant I have seen it actually work as advertised on was the pink color sealant Piper uses on some models to seal the fuel panels onto the lower wings. The sealant urethane cutters that you can buy that look like they thread onto a 90 degree drill are AMAZING! They cut through sealant like you wouldn't believe. You still have to do some scraping with a plastic scraper (especially around rivet tails) but it will get rid of most of the sealant. I have used these a lot on Citation fuel bays where I was unable to bend my arm to reach with a plastic scraper. If you do purchase these, please beware, they are ment to be used with a slower RPM motor. I believe if you buy the kit that comes with what looks like a 90 degree drill, the motor only spins around 900RPM. If you use them with a regular 90 degree drill it will melt the cutters before cutting through the sealant (ask me how I figured that one out ).

[sblack]

Thank you Patrick.

[DanH]

Originally Posted by N941WR

One thing, and this is very important, DO NOT clean up the tanks or rivets with MEK!

FWIW, a survey of blistered builders did not find MEK usage to be a common factor.

[Brantel]

Originally Posted by N941WR

One thing, and this is very important, DO NOT clean up the tanks or rivets with MEK!

Used a ton of MEK building my tanks. No blisters yet.