Spots on tank

[Dr. Lecter]

Freshwater rinse after diving saltwater is good. Knock the boot off every so often and give that part of the tank a rinse, too.

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?

Stopping the process would mean your steel tanks would begin rusting away--it's like asking if you can remove the paint on a painted steel tank. Do not spray anything on top of the existing hot-dip galv coating--at best it will just leave a silvery mess everywhere you lay the tank, and at worst it could get in the way of the zinc coating doing its work.

A bit of white stuff just means the zinc coating is reacting with the salt water properly--protecting the tank by converting to zinc oxide (the white stuff) rather than the tank converting to rust--but a lot of it would inhibit the zinc's ability to work properly.

What you have there is fine, just leave it be; five times what you have there is still fine; if the entire tank were heavily encrusted with white stuff then you'd be well advised to get it good and wet and lightly scrub/brush the white junk off so some zinc could be exposed to act as an anode. I've never actually seen a galvanized tank get that bad, though, so don't worry about it.

 

[dumpsterDiver]

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.

The oxidation will continue!

The collagen in your skin will continue to break down, your joints will degrade, your visual acuity and hearing will continue to decrease. Worry about important stuff.

edit: Oh by the way, using acid to remove zinc oxide (vinegar has acetic acid in it) definitely is a good way to remove zinc oxide (and the zinc itself) . Lots of little bubbles.. I once used muriatic acid solution to "clean" an old encrusted galvanized anchor I found.. BAD, bad idea.. completely ruined it...

 

[Compressor]

DumpsterDiver is there a reason you need to insult people who ask a question? Any reason to call other divers a dork? If I knew the answer I wouldn't have asked.

 

[Dr. Lecter]

DumpsterDiver is there a reason you need to insult people who ask a question? Any reason to call other divers a dork? If I knew the answer I wouldn't have asked.

I think he was referring to his own acid washing attempt (which was a lot dumber and more damaging than vinegar, which is pretty harmless stuff unless you soak something in it for a few days).

 

[kwinter]

DumpsterDiver is there a reason you need to insult people who ask a question? Any reason to call other divers a dork? If I knew the answer I wouldn't have asked.

Welcome to Scubaboard


iPhone. iTypo. iApologize.

 

[redacted]

DumpsterDiver is there a reason you need to insult people who ask a question? Any reason to call other divers a dork? If I knew the answer I wouldn't have asked.

I think you should be thanking him for a helpful post intended to advise you against doing something that might damage your tank. I'm not sure what you found insulting. The "dork" was obviously targeted at the guy who damaged an anchor using acid.

 

[Max Speed]

It is called white rust if it is soft and somewhat waxy. It is a failure of the zinc surface to passivate properly. It should be removed with a relatively soft brush and then the surface allowed to passivate again. It is helpful if the water has a pH between 7 and 8.2. When chromate washes were banned, the manufacturers were no longer able to effectively passivate galvanizing.

 

[Hickdive]

Aah, 'tis the Gallopin' Bottle Rot! You gets it from your nasty, unhygenic scuba ways.

 

[Chugwhump]

All divers are dorks.

And I am their most dorkiest King.

Chug
Outta' here.