tank cleaning

[marty]

Hello everybody,
can someone recommend the best method to clean a gas tank of varnish and gunked up gas? The combat wombat I purchased does not appear to have any rust, but does have the residue of old gas sitting in the tank. I have a 74' Yamaha mx 125a resto project and on that tank I used white vinegar to treat for rust and it worked pretty good. Just wondering if someone has a different method. What about acetone to clean tank?
Thanks, Marty

[Dale]

Marty,
No rust? How lucky!
My concern with using acetone would be keeping it off of the exterior chrome surface. Vinegar does work pretty well for light rust, but since you don't have any rust, not sure about that either. I would start with a small amount of mineral spirits and a handful of steel BB's. Make sure that you remove the petcocks first and twist some rubber stoppers in their place. You can also place a piece of plastic food wrap on the fuel opening and then put on the cap. This keeps things from sloshing out while you agitate the tank.
Dale

[Droptarotter]

Use Rusteco;

http://www.rusteco.com/

That is what I used on my tank and it worked great.

Cheers

[taber hodaka]

Marty acetone seems to do nothing with gummy sludge and dried gas oil residue. My best results are with a few cups of lacquer thinner and some clean gravel or nuts ect. I pour this out and filter it and repeat until no more guck comes out. The threads on the petcocks are english not metric if you want plugs. Clarence

[marty]

Thanks everybody for the advice. I will let you know about the progress.
Marty