Re: 2 six gallon OMC J/E tanks to work on!

[aquasonic]

Mumbles is right. Whatever you use will be thrown away. I have used about a dozen solvents for tank cleaning and have found inexpensive ammonia to be most effective. It is environmentally more responsible also. Just don’t use it in the presence of brass. Ammonia destroys brass.

I have a box of 100 1/4" hex nuts that are added to the solvent in the tank and can be shaken (not stirred) occasionally to mechanically loosen the petroleum deposits. Once the deposits are cleaned, you will be able to inspect the tank for internal rust. If rust is present, electrolysis is very effective in the removal.

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