As a follow on from the previous post concerning engine case painting and fuel resistance I have a similar question related to painting the fuel tank. I have had problems with fuel leaking from the fuel cap which I am trying to resolve but it is not easy. The main problem is that the fuel gets under the paint and lifts it. I have used 2 pack paint and primer and although it does seem to have some fuel resistance it is certainly softening.
My question is what is the best way to try and avoid this - best paint type/primer? best way to paint round the filler neck?
On the cb77 the neck of the tank filler is barely raised above the main body of the tank and although I took the paint off the surface that contacts with the cap, fuel has still got under the paint.
Any suggestions on how to avoid these problems appreciated.
I had the tank on my CL77 repainted by a professional painter, after twelve years of use there is no any signs of the paint lifting in the area around the cap. I don't know if there is any magic involved but the raised are under the seal and about another 1mm was completely masked off and has no paint at all in that area.
If the cap sealing washer is in good condition there should be no fuel reaching the 'edge' of the painted area, unless you spill some when fueling up which I suspect most of us manage to do!.
The raised area round the filler often seems to get damaged and then the cap doesn't seal properly which could lead to the paint lifting even if the tank had been painted in the same way as mine, one problem causing another as is so often the case with old bikes.
I have read somewhere that a small bead of super glue along the edge of the paint can prevent the fuel from getting under the paint.
I have heard of this a few times and thought I would throw it your way FWIW. Rusty
I had actually tried gluing down the paint that had lifted with superglue and then putting a ring of jb weld round the edge to try and stop fuel getting underneath the paint but it has not worked.
Maybe if I had done that from the start it would have been OK but to make matters worse the same thing is starting to happen on my other bike that was professionally painted.
(ps I did let the jb weld fully harden!)
Having gone through the process of painting my tank three times due to the paint pickling up around the cap I thought I’d update you on the final result. After the initial spray job the paint pickled within a few weeks. I flatted the paint back to bare metal, re -sprayed and then applied petrol resistant lacquer. Unfortunately I did not follow the instructions to the letter, basically I just applied three coats in quick succession and the result was it would not harden. I left it for six months thinking it would harden eventually but it stayed soft enough to mark with just hand pressure. Anyway, I removed all that lacquer and most of the paint and started again. Re-sprayed the tank, left it for a good two weeks, then applied the lacquer as per the instructions. That is, one thin coat, leave for a minimum of 15 mins but no more than an hour, then apply another coat and wait another 15 mins but no more than an hour and then a final coat. After an hour you cannot apply more lacquer! The final result is it now looks ok and after a few months of use there is no sign of the fuel lifting the paint around the filler. Hope this helps