I have an old 275 gallon fuel oil tank in my basement. It is showing some signs of rust.
Am thinking that a new coat of paint would be a protective measure.
What kind of paint/primer should I use? I read something about Galvanized Metal etching paint. Is this required? I'm not sure if the tank is galvanized, and even if it is would it be needed with the coat that is already on…
There is one coat of paint on it already which I believe is just wall paint.
I have used a bit of steel wool on it already. I concerned now that the wall paint did more harm than good. Do I need to completely remove it?
Best Answer
It's possible to measure the thickness of metal with ultrasound. Since water is heavier than oil, but has water vapor, you only need to check the bottom and top of the tank.
Yes, the wall paint is useless and in the way of proper paint prep. Despite what certain TV ads say, you can't really paint over rust.
The ideal coating is media blast to near white metal, then MIL-PRF-26915 primer, epoxy primer which can accommodate a variety of topcoats, then a 2-part LPU coating. We can whittle that down to something achievable.
I have had very good luck with the following:
If you don't use a 2-part epoxy, then finish it up with an alkyd (oil) topcoat.
If you do use a 2-part epoxy primer, you're done if the tank is shielded from the sun. UV light from sunlight will wreck epoxy. So you'll need to swiff-sand again and topcoat with, well, you can topcoat epoxy with pretty much anything, even that wall paint. Maintain the topcoat, don't let the epoxy primer be exposed to UV.