Cleaning aluminum tank

[zarn02]

Okay, I wasn't totally sure where to put this since it's a 'tech' thing that somebody here probably can help with, but it doesn't relate to a motorcycle.

*shrugs*

Anyway, my pops has an old airplane (an Ercoupe), and the engine will run on car gas, so he's done so. But he hasn't flown in quite awhile, and he's doing some work on the plane. He put in some av-gas, and come to find out the aviation gas peeled the old, varnished car gas off the walls of the fuel tank. Now we have some varnish, some floating, fuel-filter-plugging varnish, and general unpleasantness.

Anybody know an effective, relatively simple, and safe-for-aluminum method of clearing out a tank, then cleaning it up?

[Ddan]

http://www.por15.com/MARINE-CLEAN/productinfo/MCG/