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Paint bubble over fuel tank rivet

bob888

Well Known Member
That's pretty much it...I noticed this bubble about 1/2 inch diameter over a rivet on the top of my fuel tank. Doesn't seem to be getting bigger. Any suggestions; perhaps doing nothing?
 
That's pretty much it...I noticed this bubble about 1/2 inch diameter over a rivet on the top of my fuel tank. Doesn't seem to be getting bigger. Any suggestions; perhaps doing nothing?

I would at least pull off that circle of paint. Otherwise you run the risk that it continues to do it's thing and grow, making a large area of delaminated paint.
 
Dan - when the time comes for re-paint, how can the rivet lines be resealed to prevent this happening again?

Not Dan here, but you could squeegee proseal over the rivet heads and then with a moist solvent rag, wipe off all of the sealant. There will be a fine seal around each rivet head that will allow the paint to stick to instead of bridging the gap between the skin and rivet head. You will still see the head and the dimple after it's painted.
 
Dan - when the time comes for re-paint, how can the rivet lines be resealed to prevent this happening again?

I don't know for sure. A squeegeed application like Warren suggested might work. Some have wicked Loctite into the rivet dimple, some have tried to suck in thinned sealant, and so on. Trouble is, we rarely hear how the fix is holding up 10 years later.

The fundamental cause is very similar to a smoking rivet, i.e. relative motion of the rivet and the two fastened sheets. Contributing factors are the relatively high vapor porosity of proseal (it's really a sponge) and the very low porosity of current paint formulations. Movement breaks the paint adhesion, starting at the edge of the rivet, and pumps the spongy proseal. With a little vapor in the new void under the paint, heat does its thing and the blister begins.

Photo below is the inside of a blister, i.e. the back side of a paint blister sliced off the tank.
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