Steel Gas Tank Refinishing

The old school way is to remove the petcock & gas cap and pour a pint of diesel fuel in the sealed tank then add a hand full of nuts and bolts and shake it up baby. Then LUBRITECH sells a tank sealer to make sure any left over rust won't block the fuel valve or carb school way is to remove the petcock

Unless they have watered it down, I have had good results with Yamaha's two part tank cleaning system. It works very well. Only seal as a last resort. The ethanol fuels have lifted a few different sealers I had used on tanks for years before the corn craze came into play.

When a sealer starts to turn loose in a tank, it's a real pain to get it clean again.

The cleaning procedure should work.
As far as the tank coating....I used some marine fuel tank coating many years ago on a street bikes fuel tank. I don't remember what it was called, but I did get it at a local boat shop in Houston. The stuff is still in that tank today. The rest of the bike is not good now, but the tank is just like when I finished it.

Paw Paw

I did a 75 CB360 tank once that had a little rust inside. I think I either put coke, or mountain dew in it, with a handful of drywall screws since they're sharp and pointy and shook it once or twice a day for a week or so.

Good idea to count the number of screws you put in, just to make sure you get them all back out

I'm lazy so i started putting a peace of foam around the tank and putting it in the dryer, Oh make sure the old lady's not home and forget it in there.

Metal rescue is what I used for a honda cl 100. It has no smell is not acidic.