Spots on tank

[Compressor]

Dear friends:
Can you tell me what these white spots on my tanks are? I thought they may be salt so I soaked the tank in a bucket of water. And they still exist 24 hours later. Tank just got VIPed and the inside is good as new.

Thank you

 

[RickyF]

It's erosion from salt not being rinsed off after diving salt water. Salt and aluminum do not get along.

 

[Compressor]

I think the tank is steel.

 

[dumpsterDiver]

Zinc oxide? The corrosion of the galvanized coating is occurring..

 

[Akimbo]

Zinc oxide? The corrosion of the galvanized coating is occurring..

I concur. Hot dip galvanizing functions as an a sacrificial anode... basically the zinc gives up electrons before the steel, this protecting it. It is the same reason that zinc blocks are attached to steel boats and ships.

 

[Compressor]

I appreciate the contributions.
Anything I can do now to stop the process? I rinsed with vinegar. Hopefully this will not get worse?
Should I be spraying some kind of "galvanizing" paint on the spot?


I think what happened here was that my tanks were stored during the winter in the garage and got road salt on them. I should have been more careful but its happened so now need to figure out what to do.

Thanks

 

[Akimbo]

Most steel tanks will outlast you with a fresh water rinse. It will become a darker gray and splotchy but that helps to inhibit corrosion of the zinc.

 

[whitefang21]

what can he do to bring back the shine on the tank?

 

[Compressor]

Thank you WhiteFang21. I am really only concerned that the oxidation will continue and I need to find a way to stop it. Cosmetically I don't really care how it looks.

 

[victorzamora]

As was said above, good fresh water rinses after diving in salt is all that would be necessary. That kind of stuff is proof that the anti-corrosive measures are working. Dark spots, as mentioned above, should help the anti-corrosive measures last longer. Fresh water after salt water is the solution to having your tanks outlive you.