Well, I've used sand blasting sand and gravel in the tank and then shook the heck out of the tank. Wash thoroughly with water before and after. Friend says he does the same thing with glass marbles to prevent sparks. You don't want to blow it up. But I think a thorough washing with water first should prevent any possible gas fumes from remaining. It's an easy way to sandblast all the rust out of your tank. Dan <ThatVWGuy@xxxxxxxxxxx> wrote: One of the hurdles in getting my bus on the road is my gas tank. Since it hasn't been used in 10+ years I need to clean it out before using it so I can avoid changing my fuel filter every 100 miles for the next three years. I have heard of people having their gas tanks "boiled out" but have no idea what is involved in that process. I stopped by the local custom shop and they said they just flush them out with a garden hose. Seems to me there should be more to it than that. Can anyone offer any insight? -Dan