DThela: I am familiar with the POR15. I used it to seal/coat a tank on my 37 back in 2000 and it is doing just fine. You buy the kit for about 50 bucks but haven't priced them lately. It takes a little time to go through the steps but the end results are nice. Then coat the outside with some regular POR15 and your set to go. I think a little can of the regular stuff come with the kit. Hope this helps.
NO....mine is not even close to being repairable.
As for the DENT..it can be pulled out if it is not creased. I bought a suction cup at the local parts store some time ago and I have pulled "concave" dents out of doors and even a gas tank. Smooth the place so the suction piece will grab hold...then give it a good yank.
