Have to change gas tank on wifes car--bought a used one --good shape , but looks like a little varnished gas and maybe some dust in it.Should I just swish some gas around in it and drain it ,or is there something better to do? thanks
I've cleaned out motorcycle tanks with laquer thinner worked well on varnish but won't touch rust. Robert
my sound funny but i used some gas let it sit for a couple days and than flushed it out with water and all the varnish came out with it ..
if the varnish is thick ..while using a solvent..throw some small nuts or bolts that will come back out easy to help loosen up the scum..put them in and shake it up while its sealed off with some tape.
Years ago I used to carry them to the radiator shop and have them vatted but not sure if they still do that or not. One thing to keep in mind if it is a pump gas application is that with the 10% ethanol in the fuel now it is acting like a detergent and cleaning any deposits in the older tanks and sending them upstream so make sure and get everything you can out. Filters will not stop a lot of this stuff either as it is showing up as a sticky residue at the carbs.
All of the ones I work on go to the local radiator shop to get boiled out. It makes welding, sealing and lining a snap (and not a BOOM!).
I bought a gallon of paint stripper for my last tank, it cut ALL the brown varnish nicely. I then pressure sprayed it out.