Flash Rush in tank. Help

When I did my tank I used CLR (phosphoric acid), then a nice mix of dish detergent and water to wash it out, then some gas-line antifreeze to get the water out. It worked really nicely. Once that was drained, I WD40'd it, and left it til I was ready to fill with gas.. Haven't had any trouble.

WD40 will do the trick. I've never had the problem you're describing but I do know that whenever I have to leave a table saw on a jobsite WD40 will protect it from rusting till I get back to it.

You know, the phosphoric acid is only about 15% as strong as the muriatic acid. (Strong is a way relative term because all these acids are diluted to different concentrations before we start dumping them in our tanks. As a matter of fact muriatic acid is a strange term in it's own rite. Muriatic acid is the name that given to hydrochloric acid, at 20% dilution, that is commonly used to clean masonry.) My point is that the process where by Phosphoric acid attacks the steel tank and leaves you with an iron phosphate coating takes several hours even four hours is not excessive. It's the iron phosphate coating on the inside of the tank that gives the corrosion resistance needed to dry the tank without flash rusting.

KZCSI

So are you guys suggesting that I spray it with WD-40 after I rinse out the Muratic acid?

No. Use the muriatic then the phosphoric and finally use the WD40 to displace the water after you've rinsed out the phosphoric acid.

kzcsi

I'm doing another one today first wash with muriatic removed all the rust I could see but heated it up enough to reveal that there was some oily varnish hidden in the seams that I'll need to wash out first. I'll come back with some acetone and then try the acid again. I'll post the results in a few hours.

kzcsi

Patton's suggestion was a great one. I used the muriatic acid, followed it with the phosphoric acid and immediately coated the inside with WD40. I then rinsed out the phosphoric acid with a garden hose and one more application of WD40 and here's the result.

What looks to be fine cracks are a few dog hairs that were on the rag I used to dry off the WD40.

KZCSI