Fuel Tank Leak

hunt9791 · Post by **hunt9791** » Sun Jan 14, 2007 7:25 pm

I have a rivet seeping proseal on the bottom of my left fuel tank right in the middle of the tank. So I can't put a glob of pro-seal on it from the fuel cap or by opening the access plate where the sender is installed. I understand there has been success drilling out the number 40 hard rivet and modifying a 1/8 cherry max, coating it with pro-seal and installing it. Anyone have the particulars?

tshort · Post by **tshort** » Sun Jan 14, 2007 7:46 pm

Apparently there is some success with a little negative pressure to the tank then using the green loctite (I think - someone else can confirm) and allowing it to weep in and seal...

T.

captain_john · Post by **captain_john** » Sun Jan 14, 2007 10:06 pm

I heard about the goopy pulled rivet trick. I think it was in the "RVator" publication. They say it works!

I am not sure about the particulars. Lemme see if I can locate it for ya.

CJ

Wicked Stick · Post by **Wicked Stick** » Mon Jan 15, 2007 11:37 pm

Ok, I'm confused.. seeping proseal... won't it just harden up and seal

If you meant weeping air/fuel then I get it..

captain_john · Post by **captain_john** » Tue Jan 16, 2007 6:58 am

That was my assumption, Dave.

Air, seeping past a poorly prosealed rivet.

Are we correct?

CJ

hunt9791 · Post by **hunt9791** » Wed Feb 28, 2007 7:28 pm

Let me clarify: Fuel leaks past the rivet, but you see a black streak for about 6 inches behind the rivet, which I assume means some of the proseal is being disolved or carried in the process.

Wicked Stick · Post by **Wicked Stick** » Wed Feb 28, 2007 8:34 pm

If this is a flying aircraft, then I'd say the black streak is probably from the loose rivet vibrating and it's aluminum dust ?

I would think you'd also have a blue streak/stain from the fuel residue.

I have heard that you could try the locktite method, but since your weeping is from a bottom rivet, you may have to remove the tank and flip it over to allow the locktite to weep into it from above.

If that doesn't work, you could go the other route with the pro-seal cherry max.

captain_john · Post by **captain_john** » Wed Feb 28, 2007 9:29 pm

I agree, Dave.

If there is no blue, it is just a "smoking rivet" trailing AL dust and oxidizing.

To drill it out, smear in proseal and snap a blind rivet would be my choice. I would use one of those solid baffle rivets, though.

CJ

cnpeters · Post by **cnpeters** » Thu Mar 01, 2007 4:08 pm

I saw a reference in the VAF archives to the negative pressure trick mentioned above but with diluted proseal that worked for someone. I don't recall the solvent, but they claimed the leak stopped. Personally, I would do the drill out and pulled rivet replacement.

jim_geo · Post by **jim_geo** » Thu Mar 01, 2007 7:38 pm

When I thinned Proseal I used a small amount of Toulene and it worked very well.

LooseNut · Post by **LooseNut** » Fri Mar 02, 2007 1:27 pm

If you drill out the rivet, doesn't that put some loose metal bits and shavings into the tank???

LooseNut

captain_john · Post by **captain_john** » Fri Mar 02, 2007 4:06 pm

Yes it could. That is why we have screens, sumps and gascolators.

Gotta fix it, though!

CJ

TomNativeNewYorker · Post by **TomNativeNewYorker** » Fri Mar 02, 2007 4:10 pm

LooseNut wrote:If you drill out the rivet, doesn't that put some loose metal bits and shavings into the tank???

LooseNut

I guess if one is very careful, you could just drill deep enough to pop the head off, and use a drift punch of the correct diameter to knock the bucktail through. One bucktail may be better than a bunch of shaving fuzzies floating around inside.

LooseNut · Post by **LooseNut** » Mon Mar 05, 2007 12:35 pm

Gotta fix it, though!

True.

Just thinking that maybe one of the no-drill fixes might be worth a try first to avoid bad stuff in the tank. You know, the seeping Lock-Tite or something else that has already been suggested. ... If that doesn't work, then go to the drill-the-rivet solution.

It might work out, or it might end up being more futzing around. Maybe worth it to avoid bad gas ju-ju.

I guess if one is very careful, you could just drill deep enough to pop the head off, and use a drift punch of the correct diameter to knock the bucktail through. One bucktail may be better than a bunch of shaving fuzzies floating around inside.

Yup, with some care, ya ought to be able to minimize the problem, probably no shavings in the tank at all ... they would all be falling on the outside of the thank.

... always thinking of what can go wrong ... call me Mr Sunshine!

svanarts · Post by **svanarts** » Tue Mar 06, 2007 1:30 am

LooseNut wrote: ... always thinking of what can go wrong ... call me Mr Sunshine!

Sounds like Mr. Sunshine just doesn't want his buddies to get hurt. You go Mr Sunshine!