I used a product called Slosh.
This was on a newly repainted tank, which sprung a leak on an unseen pinhole, which turned into several pinholes with a bit of scraping.
First I cleaned the damaged tank area with a die grinder (like a dremel only much bigger and the cutters WAY more expensive) then I pluged the pinholes with "Quicksteel" a chemical metal, next I cleaned the tank internally (twice) by filling it with water laced with De-OxC, this found another tiny pinhole or two, both times the tank was left in a warm place for a week.Then I used the slosh, it is a single can treatment which cures useing the water in the air, so they recomend leaving it a week, I left it three weeks,all is fine, and the paint undamaged.
I have set up a "test" with the empty Slosh can, as when I laid it on its side, the residue of Slosh hardenned, so I half filled it with fuel, punched a pinhoole vent in the lid, wrote the date on the can, and periodically, I look in there to see how the Slosh is doing, changing the fuel each time, so far so good, the fuel has not damaged the Slosh which is the object of the test., but then its only been six months and four fuel changes.
CLEM
