For what it's worth, Faber tanks use a "spray coating" galvanizing process. Cold spray galvanizing doesn't protect steel as well as a "hot dip" process. So Faber tanks are a bit more susceptible to seawater corrosion than hot dipped tanks.
For those who don't understand what galvanizing is, zinc, which is highly resistant to corrosion, is electrochemically bonded to the steel tank. The zinc "layer" varies in thickness, depending on the application and the manufacturer's specification, and the thickness of the zinc layer determines the service life of the equipment. For instance, a 5 micron zinc layer gives the galvanized item a service life of approximately 100 years; "service life" being defined as the time to a five percent rusting of the steel surface.
If the tank has already begun rusting, the damage is already done. Merely grinding off the rust and painting the tank won't solve the problem. Indeed, taking a grinder to the tank guarantees that you'll cause further damage to the zinc layer. You're also scraping off layers of steel, which I don't think is such a great idea for a high pressure cylinder.
Applying primer and a paint coat on the metal will not adequately protect the tank, even if you could get the paint to adhere. The other problem is that metal oxidization occurs on a microscopic level, and removing the visible rust does not guarantee that you've eliminated the oxidization problem. Slapping a coat of paint on the cylinder may actually hide a portion of the tank where oxidization is continuing.
If you really want to fix the problem, I would suggest that you check around for companies that provide post-fabrication galvanizing and talk to them about how to clean the tank and reapply the zinc.
For those who don't understand what galvanizing is, zinc, which is highly resistant to corrosion, is electrochemically bonded to the steel tank. The zinc "layer" varies in thickness, depending on the application and the manufacturer's specification, and the thickness of the zinc layer determines the service life of the equipment. For instance, a 5 micron zinc layer gives the galvanized item a service life of approximately 100 years; "service life" being defined as the time to a five percent rusting of the steel surface.
If the tank has already begun rusting, the damage is already done. Merely grinding off the rust and painting the tank won't solve the problem. Indeed, taking a grinder to the tank guarantees that you'll cause further damage to the zinc layer. You're also scraping off layers of steel, which I don't think is such a great idea for a high pressure cylinder.
Applying primer and a paint coat on the metal will not adequately protect the tank, even if you could get the paint to adhere. The other problem is that metal oxidization occurs on a microscopic level, and removing the visible rust does not guarantee that you've eliminated the oxidization problem. Slapping a coat of paint on the cylinder may actually hide a portion of the tank where oxidization is continuing.
If you really want to fix the problem, I would suggest that you check around for companies that provide post-fabrication galvanizing and talk to them about how to clean the tank and reapply the zinc.