Tips for cleaning rusty tanks?
 

Anyone have any good tips on cleaning a rusty tank?
It is not for my hawk.
I have a 71 cb350 that has a tank with surface rust all over the inside of it. The tank has great paint. So I do not want to dunk it and have to repaint it. Also, I do not want to use any sealers or foams that will coat the tank with some crap that falls off in 6 months. I have read on other forums that muratic acid works the best, followed by a phosphoric acid, followed by cleaning and coating in wd40.
Has anyone heard of this theory or have any good thoughts or solutions on how this should be done?
Thanks!

When I have a project with a rusty tank and good paint I'll take it to my local radiator shop. They can internally clean the tank without damaging good paint. Then I'll use a good tank cream as the tank will of lost it's protective lining and will rust again.

+1

That is a great idea.
Unfortunately, the exact opposite of what I need done on this tank.
My local radiator shop said I would have to repaint the tank afterward, and I am not going to use a cream on the inside.
Thanks for the thoughts! But, anyone else have an idea?

You have pretty much run the gamut of choices. There is no way to remove the rust unless you want to sand/bead blast the inside but then you have removed the protective surface coating and it WILL need something on there to keep it from rusting again.

I have had good results with KBS products:

Gas Tank Sealer - Gas Tank Liner - Diesel Tank Sealer - Fiberglass Tank Sealer

I have used the Por15 kits on many older honda tanks. Its amazing stuff and really has held up very well. You can just treat, or treat and seal, it ends up looking like new at the end. you can search on them. You can protect the outside easily and its not too bad a job. As opposed to cream sealants I have never heard much negative about this method.

I am currently restoring my '98 Hawk which sat for 5 years w/ about a 1/2 tank full of old gas in it. I used POR 15 tank restoration which is a 3 step process (sealing being the last step). You can clean the inside w/out sealing. The tank came out fabulous and was totally worth the 40 or 50 bucks.

hand full of nuts and bolts and shake till you cant anymore. then it still need more shaking. then rinse a lot, and then fill her up worked for my old 71 at1

+1 on POR 15. Follow the instructions explicitally and plan it taking a week to complete the entire process. My results were excellent. Patience is a virtue.

I saw someone remove rust with a form of electrolosys. Google it