Steel 72s corrosion

[ghost68]

just picked up 8 steel 72s for $10 each. They are all a little banged up; valves definitely need some cleanup, lots of corrosion under the boots a nice dose of flash rust inside throughout but no rust on the outside from what I can see. They are all out of hydro.

What I want to do is strip off the corossion from the outside of the tanks so I can regalvanize the ones that are worth holding ok to and scrap the rest. My goal is to get 4 good ones back to looking newish. If I can avoid manual labor (sanding grinding and scraping) that would be great. I have some muriatic acid and naval jelly. And chemical stripping would be awsome. I would also like to avoid sending these out to get blasted if I can help it.

I have looked at the stripping and repainting steel tanks thread and did not find anything useful

Please don't respond with "don't do it its a waste of time" I WANT to do this.

Thanks again everyone for reading this
-Dustin

 

[DA Aquamaster]

By "corrosion under the boots" I assume you mean some whitish looking stains rather than rust. anything other than very minimal surface rust would be bad and most likely would be cause to condemn the tank.

Muratic acid is a bit strong but if you dilute it to about 3-4% by adding 4 oz of muratic acid to 32 oz of water it should help remove the staining from the base of the tank without damaging the galvanized finish. When you are done be sure to soak the base of the tank in a solution of baking soda and water, then rinse thoroughly.

If the galvanizing is gone or very thin, you can paint the tank with a cold galvanized finish, but the concern would be whether there is indeed any pitting once you remove any salt, stains and oxides.

The tank will need to be tumbled to remove flash rust before you can really determine if any pitting is present.

 

[captain]

If there is any galvanize at all left chemical / acid striping would remove it which is not good, any is better than none. Abrasive or bead blasting is the best method by far, It won't remove any good metal and it will get any rust out of pits making it easier to determine the depth. A lot of tanks that look bad when the boot is removed aren't as bad as they look. I wouldn't do anything unless there is actual red or brown rust showing in the boot area and not just the white or purpleish corrosion. Usually the white corrosion will tend to wash off over time if the boots are left off.

 

[NorthWoodsDiver]

Slick deal on those tanks, consider yourself lucky. Make sure you open them up and inspect the inside before cashing out lots of $$$ on the exterior.

 

[pescador775]

"Stripping and regalvanizing" are not terms with which I am familiar with respect to hot dipped tanks. A little cleaning and spraying can be done safely, however.

Flash rust is no big deal but maybe you will define that condition more precisely. Emory cloth and steel wool will remove the most blatant crust/powder from the exterior. A fair amount of elbow grease is needed. Spray on some Krylon aluminum paint to make shiny or use some ZRC "zinc rich" if you feel it is needed. But, you said that you were only going to salvage the "best" tanks if I understand accurately.