Summary for marine corrosion coating materials Discussion
marine corrosion coating materials is the core issue here: Luis Díaz asked for candidate coatings for gas cylinders exposed outdoors in the Gulf of Mexico, where sun, moisture, and salt are severe, and said the options would be compared in a salt fog cabinet. Ted Mooney initially assumed the question might be about interior coating, but Luis clarified he needed an exterior coating for outdoor exposure and was concerned that epoxy would suffer under UV. Steve Rodgers replied that the US Navy uses epoxy powder coatings inside high-pressure air flasks to prevent corrosion, noting a military specification exists, but that advice applies to internal service rather than outdoor weathering. Years later, Alberto Valenzuela suggested polyurea as a possible exterior option, saying he had read of its success. The thread does not settle on a single best material, but it highlights the importance of distinguishing interior versus exterior exposure and considering UV resistance for marine service.
Q. Dear All,
We are looking for candidate coating materials for use in gas cylinders that will prevent marine corrosion.
Thanks in advance for your help.
Luis Díaz
– Mexico
1996
“Standards for Visual Inspection of Steel Compressed Gas Cylinders”
by CGA
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A. You probably want some powder coating other than epoxy. You probably need to remove weld scale, blast the cylinders, phosphatize them, and then powder coat them.
Or if you want to job it out, there are several capable shops listed in our Directory of Finishing Shops.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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A. US NAVY USES EPOXY POWDER COATINGS INSIDE HIGH PRESSURE AIR FLASKS TO PREVENT CORROSION. THERE IS A MILITARY SPECIFICATION FOR THE COATINGS
STEVE RODGERS
1996
Thanks, Steve.
I understand that epoxy is usually not ideal for outdoor exposure because of UV sensitivity. But now I am confused whether Mr. Diaz is looking for a coating for the exterior (which I had assumed) or the interior (which I guess you are assuming).
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
1996
A. I don’t see any mention of the base material. “Gas cylinders” is an ambiguous term.
A couple of years ago I read in the paper where a man wanted a nice epoxy powder coat finish on his scuffed up scuba tanks. Got a local supplier to do the job. First time he filled the tanks, 4000 psi, kaBOOM. 1 killed, 2 injured. Cure temp of the EPP annealed the Aluminum scuba tanks …
Although Mr. Diaz did say “in” the cylinder, in this case I would specify a weldable, marine corrosion resistant base material and go easy on coatings.
Harry Andreas
Firstly, thanks to all for your interest in this subject.
I want to say that Ted Mooney assumption is correct. I am looking for a coating for outdoor exposure. And as far as I know, epoxy under these condition will have problems because the UV. In fact the cylinders will work in the gulf of Mexico where are a lot of sun, moisture and salt.
The candidates will be compared in a Salt Fog Cabinet.
Thanks again for your messages,
Sincerely,
Luis DÌaz [returning]
– Mexico
1996
A. Luis,
Why don’t you consider use Polyurea? I have read a lot about about it where polyurea has a huge success.
Regards
Alberto Valenzuela M
– Arequipa, Peru
August 17, 2013