I just wanted to post the results of a rather long term test of POR 15 gas tank sealer. Somewhere over 15 years ago, I coated the tank in my 40 Ford pickup project with the stuff. Since I was using a used Ford Ranger tank in my project, I thought it would be a good idea to stretch the life of the tank a little by coating it. Well, when I took the tank down to clean it, I found that you could see through the tank in multiple places, especially where the hanging straps contacted the tank. Now, coating the tank was just an activity done on a hoot since the tank was clearly junk. In fact, I had to close up the holes in the tank with duct tape to keep the sealer from draining out when I did the coating! Nevertheless, I cleaned and coated the tank per the instructions. As time would have it, it was a few years before I got to actually use the tank and it had spent plenty of time in the truck with the top open, just taking on water and dirt. 4 years ago, I finally cleaned it out with a shop vac and put the tank in service. It's been holding perfectly fine since then. This week I decided to get around to installing the right sender for my fuel gage. I reasoned since the tank was now 30 years old and it had been sealed once, I should spring for a new tank. I bought a new tank and fitted it with the sender. Then I took the old tank down and removed the fuel pickup. That tank was a clean and solid as when I coated it over 15 years ago! I don't know what's in that stuff but it works for sure!, no gooey stuff, no peeling just a nice silver lining. I just wanted to let everyone know in case they're faced with sealing a gas tank somday.