Originally Posted by bwringer
Who said anything about a plastic tank?
Anything that would dissolve Kreem (we seem to have votes for both acetone and MEK here; dunno which is better or correct) would also run the risk of damaging a plastic tank, so you'd need to consult a polymer chemist...
But yeah, I know the POR15 stuff is rock-hard when it sets up, so it would be a pretty bad idea with a plastic tank for that reason alone. I haven't seen a sample of the cured Caswell stuff.
There are lots of plastic tanks out there. Some swell up, others delaminate from today's witches' brew everyone thinks is gasoline. I've never seen a plastic tank that's been Kreemed, so I wouldn't comment on how to get it out.
Caswell is a phenolic epoxy that sets up almost clear with a slight yellowish cast. It works well as long as the instructions are followed exactly. I've used it on rigid plastic tanks with good results. I don't think anything would work well with the flexible polyethylene tanks sold for dirt bikes.