What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Fuel tank leaking rivets

mikelupo

Active Member
Patron
Maybe

I would bet the NPT bung fitting was installed dry by the looks of things. If it was mine, I would take a shot at an external seal that may or may not last, but you would need to drain all fuel, clean..really clean the area to be free of paint dirt and fuel all around the fitting and the rivet tails. Stainless wire brushes, ect and then final clean with MEK or Coleman lantern fuel (my favorite). I would then apply a brush coat of PR1422A 1/2 sealant over the area, let cure, and then apply a second coat. After you apply first coat, stick the Proseal in your freezer and it will still be usable for the second coat a few hours later. If the rest of your tanks were put together with dry areas, you may unfortunately find other leaks down the road that will require tank removal. I just did a re-seal on an RV-8 tank that had the bungs installed dry and no leaks after years of flying, but other areas leaked requiring removal.
 
Thank you for the suggestion Bill. I will try that proseal process. Looks like to do it I may need to remove the tank in order to get at it amply so as to clean it. If I have to do that I might go ahead and reseal the rivets correctly. Especially if I find more leaks. I have oversized rivets for just this sort of thing. Would I use the same proseal formulation for that?

Since I posted this, I saw a youtube video of someone fixing a flush rivet on top of the wing with a sealed pop rivet. This is not the same application though but I wonder if i drill the rivets out from the tail end, could I use a sealed pop rivet in its place?
 
A couple more things.

The rivets themselves likely don't need replaced, and driven rivets are "hole filling" meaning they swell to fit the hole when driven. However, all tank components should be assembled "wet" with sealer when built thus preventing minute seeps as likely in your case. I would not recommend drilling out the bung rivets and replacing with closed end blind rivets. For one, the bucktails left inside are a risk for fuel system contamination. Any rework/sealing in the root bay (I haven't looked at a -10) are usually accessible through the fuel sender access plate and don't require surgery or additional cut-outs. Once you get access to see the backside of your leak area, loose sealant if any, can be cleaned up , the area scuffed with scotchbrite, and and resealed. The "A" designation sealant is thinner than "B" and penetrates into nooks and cranny's. It was developed primarily for top-coating fasteners and areas where flow was required. The thicker "B" sealant is more difficult to work into tight spots, but is better at filling large gaps, as well as staying in place during major assembly.
 
Back
Top