"Another" Gas tank thread

[Scotty777]

So I have poured over the existing threads and see the common theme of using lye/acid/vinegar etc. to get our rust. My problem is a little different and I didn't see an existing thread on how to deal with this issue.

I recently purchased a cub in which the tank had been previously treated with a silver coating of some sort. However, it appears the prep work was not perfect and there are large chunks of this coating coming off (carrying the rust underneath) and clogging up my fuel system.

Has anyone dealt with this situation themselves?

Would one of the documented methods work? If so, which one would work better?

I'd really like to save this tank, it's in much better shape (on the outside) than my other cub's tank I'm currently using as a temporary solution.

Thanks for the input - Scotty

[Bob McCarty]

I doubt that any solvents will remove the coating. Here is a link to a possible partial fix: viewtopic.php?f=139&t=98978 I don't know if tumbling the tank with bolts or a chain in it will help, but I think there is a "how to" about strapping the tank to an elevated rear wheel and tumbling the tank.

[tst]

muriatic acid, just did one this morning, had some crappy red coat in falling apart, looks like it was just sandblasted now

[Clubless]

Tat...do you dilute the acid?

[k hutchins]

The new '48 l bought last year had some type of crumbling "redkote" in it that was like a cross between dried latex and dried playdough. While it was dry l used a number of make shift tools to peel and break up as much as l could get to (couldn't get behind the baffle in the rear), then turn it over to dump the pieces out of the fill neck.
After that l ordered and installed a screen "tower" filter from Steiners. Been running it for over a year without a problem.
Just last month l noticed tha what was behind the baffle has come loose and slid into the bottom. The filter tower keeps it from covering the outlet, so l'll wait until winter to try and tackle it.

[tst]

used it straight

[Pap]

used it straight

Thanks . I have a little bit of rust not bad. I will get some of that and clean it up.

[NJ Farmer]

Unless you get that tank spotlessly clean I would install an inline “backup” fuel filter before the carburetor. I don’t think you want to keep taking the carburetor apart cleaning out fine debris.

NJ Farmer

[tst]

after its clean with acid dump a box of baking soda in it to rinse it out with, it will neutralize the acid, once it is dry I spray some penetrating oil in it and swish it around so it does not rust back up

[Pap]

Thanks tst.
I was wondering how to neutralize it. That sounds like a great thing to do. And it's not going to cost to much to do that.

[Pap]

I sure am glad that I found y'all guys because I have learned a lot no longer than I have been here.

[Mht]

I’m curious about the cleaning with acid and neutralizing with baking soda. Can a tank be used as is after this process without using a coating in the tank or will it need to be coated to keep it from rusting badly again. I have a couple of tanks that need derusting and I would prefer not to have to coat the tank when done

[tst]

I have done many and never coat the tank as its clean after, may have little debris to clean a few times from the fuel bowl after as the last of it gets washed out by the fuel, no big deal, the acid will eat all the rust out and make the metal bright and shiny

[Frozenstate]

Use washing soda to neutralize the acid. It also cleans while neutralizing. Great stuff, very handy.

[Don McCombs]

Two things with the muriatic acid method…
Muriatic acid produces very strong fumes. Work with it with the wind at your back or wear a respirator. Use PPE on your hands and eyes.
Dissolve the baking soda(or washing soda) in the desired amount of water, prior to putting it in the tank to neutralize. It works much quicker and more effective that way.