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
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.
Sounds to me like Oakite [Chemetall] might be good people to start talking to.
Or if you want to job it out, there are several capable shops listed in our Directory of Finishing Shops.
A. US NAVY USES EPOXY POWDER COATINGS INSIDE HIGH PRESSURE AIR FLASKS TO PREVENT CORROSION. THERE IS A MILITARY SPECIFICATION FOR THE COATINGSSTEVE RODGERS
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).
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]
Why don't you consider use Polyurea? I have read a lot about about it where polyurea has a huge success.