Tank sealers

POR15:-
Two tanks done at the same time about 20 years ago, one worked fine, the other sheeted off later (not sure why) The one where it sheetfed off was very clean as only a small trace of flash rusting stuck to the back of the POR15.
Both tanks had the left rear corner perforation problem.

All the other tanks I've done (That are in good shape, and fuel tight) I've used Tapox (Frost's website where I ordered most recently; but a few years now).
TAPOX is a two part phenolic epoxy, similar to a ship's cargo tank coating, red in colour.
The Kit I had was enough for two tanks. It needs to flow over the entire internal so I looked like a nutter dancing round the back garden for about 20 min.
Then inverted and rags into aft of the tank cap filler aperture to get the last fluid build up out.
It then requires to be vented, contrived a computer cooling fan, and trainset power supply, with custom ducting, to draw a slight vaccume at the fuel cock spigot, to draw the flammable solvent out the tank so it cures ( CANNOT use a hoover )
Cures overnight, minimum temperature of 10C.
The drained off epoxy is great to do railings brackets, of perhaps even a frame by brush....
Oh, penultimate water rinse rinse, I put some vitamin C dissolved, as a corrosion inhibiter (ascorbic acid).

Really need to get a shot of an electric cement mixer to get the POR15 off the inside of that NA dream machine, white tank.I think I've a couple of tanks I should rework now as I'm further up the learning curve! (Half way perhaps ).