Cleaning Fuel Tanks

In an earlier post, one of our members mentioned cleaning fuel tanks with his six shooter fuel pump and alcohol. Since alcohol attracts water, what is a better, more powerful, cleaning agent? I was thinking maybe, mineral spirits, camp stove fuel, or even auto gasoline. I know the dangers of using gasoline, but it is a powerful solvent! Acetone would work, but it will really ruin your finish instantly.

Hi Don,
I remove the tank for cleaning and use whatever's handy. Usually the cheap lacquer thinner. Let it sit for as long as I can stand it, shake it, and suck it dry with a syringe that I have for that purpose.
LT will eat the stopper of the Sig syringe if left in contact for any length of time.
Bill <><

Cleaning old tanks is easier if you can remove them from the model...

Laquer thinner alcohol, rubbing alcohol (isopropyl) preferably in the 99% strength, various other thinners all can work. Consider it a multi-step process. After you've flushed out as much as you "can stand" (I liked that!) coat the interior with something that will prevent rust or corrosion.

Listen for any rattling inside the tank after you've used a solvent --small solder blobs may have worked loose. Those aren't likely to flush out, so surgery (sweating off an end cap to inspect the interior) might be indicated.

After a solvent, you can flush out with hot dishwater, then with clean water to get ALL suds out. Then you can heat the tank shell to dry it with, e.g., a Monokote heat gun. (Watch it, the metal gets hot.)

WD-40 can be used to displace any water (that's what the WD stands for-- water displacer), but is poor long-term protection. You can flush leftover WD-40 out with a little castor-containing fuel. Doesn't need a tankfull, just enough so you can slosh it around throroughly, then blow it out the feed line with a syringe or bulb on one of the vent lines (cap the other).

Should be good to go at that point, but use a filter when putting it back in service, and check the filter after each of the first few runs.

All this resumes a metal tank. If you're looking at a plastic bottle, it is a bit easier. You can (usually) see any congealed fuel, and may only need a slosh with an alcohol, a flush, and a coating of fuel. At worst, pull the plug out and swab the inside with a bit of paper towel sopping with your solvent. You can also see if there are any chunks of dried oil or whatever left, and judge whether more work is needed. Same precaution about a good filter, checked often at first.