Powder coating a steel tank

[BigJetDriver]

I've found several remarks on the web on the dangers of powder coating aluminum scuba tanks because of the temperatures involved. Apparently the heat alters the properties of the metal. Does the same apply to steel tanks?

Art,

I would suggest that you go to the acknowledged experts in the field. These would be the people who make the cylinders, such as PST, and ask to speak to someone from their technical department. It may take a bit of effort, but they can give you the unadulterated facts.

Here: www.pressedsteel.com

Cheers!

 

[tndiveinstruct1]

Good evening!

On the subject of powder coating aluminum cylinders, I did a little research and found the following URL's:

http://www.luxfercylinders.com/support/maintenance/cm5.shtml

In that article Luxfer says that the temp to be concerned about is 265 degrees Farenheit to 350 degrees Farenheit. It also states that cylinders can be painted if using a paint for aluminum that cure and dry at room temperature. It also states that the paint SHOULD be water-based.

The next URL, http://www.luxfercylinders.com/support/bulletins/20020218.shtml, talks about powder coating aluminum cylinders and the clear coat finish that they put on their cylinders WILL change color when subjected to high temperatures for extended periods of time.

The final URL,
http://www.luxfercylinders.com/support/maintenance/cm4.shtml, refers to the proper types of paint strippers to be used on aluminum cylinders.

I used these to demonstrate that it IS possible to paint cylinders and even powder coat the cylinders IF you know the particulars of the cylinder manufacturing and the painting/powder coating process.

I hope this helped you in your search....

Randy Cain

 

[ArthurGerla]

Thank you all for your comments. I've done some more online research and found that powder coating seems to be accepted here in the Netherlands, for *steel* cylinders that is. Aluminum cylinders are pretty rare over here.

 

[MikeC]

Arthur, before you do anything check with the people who fill your tanks in your hometown. "Online research" may be nice but is the data accurate?? You might spend money on powdercoating a tank only to find out that no shop will fill it.

 

[scubapro50]

Epoxy, Epoxy, Epoxy ................. NO PROBLEM ........ I have repainted both steel and aluminum with no problems ... just don't bake them. I remove all stickers everytime I get a tank hydro by using paint remover ... then use a can of spray Epoxy after they come back to touch them up. Black and Yellow really comes out looking great

 

[ArthurGerla]

"Online research" may be nice but is the data accurate?

My thoughts exactly. On-line information is pretty scarce anyway. I'll go to the source, in this case the dutch government agency that rules these matters.

 

[wedivebc]

My thoughts exactly. On-line information is pretty scarce anyway. I'll go to the source, in this case the dutch government agency that rules these matters.

Please let us know what they have to say.

 

[DennisW]

I checked with Rudy Mola of Diving Technologies International. His comment was that from his sources, you could powder coat steel tanks. Never aluminum. Rudy's comment that you should never take the steel tank above 900 degrees where the properties of the steel may begin to change.

My opinion: Why the heck would you want to powder coat your tanks in the first place? It's not a beauty contest out there. When you come up from your dive and you have mucus streaming from your nose, is anyone going to be commenting about your pretty tanks? Leave your tanks alone. They are happy that way and so are those of us that know how to inspect high pressure cylinders.

 

[wedivebc]

I checked with Rudy Mola of Diving Technologies International. His comment was that from his sources, you could powder coat steel tanks. Never aluminum. Rudy's comment that you should never take the steel tank above 900 degrees where the properties of the steel may begin to change.

My opinion: Why the heck would you want to powder coat your tanks in the first place? It's not a beauty contest out there. When you come up from your dive and you have mucus streaming from your nose, is anyone going to be commenting about your pretty tanks? Leave your tanks alone. They are happy that way and so are those of us that know how to inspect high pressure cylinders.

So what do you suggest to stop steel corrosion where the paint has chipped off?

 

[Ontario Diver]

Rudy's comment that you should never take the steel tank above 900 degrees where the properties of the steel may begin to change.
QUOTE]

According to PSI, a steel tank should be condemed if it is exposed to heat above 600 degrees.

Another thing to remember that if any of the stamped markings on the sholders (serial, manufacture, DOT/TC numbers etc.) are unreadable, the tank cannot be hydro'd or legally filled. So if you are painting with epoxy or powder coating make sure that the stampings remain clear of paint/powder.

But as Dennis said - Why bother? It scares Viz inspectors.