Hi all,

The compressor sorry, I mean the big air tank after the compressor which supplies my lathe with air is situated outside and has become rusty on it's top surface. I want to clean and paint it.

I was thinking of using that rust remover stuff that Hammerite do or manualy sanding the rust off, but then thought it might weaken the actual metal: since it's operating about 120psi I kinda worried a bit about messing about with a potential "bomb".

Anyone got the same problem please, or has anyone done this before please?

Many thanks in advance.

Just to be safe, I'd work on it with the air pressure off.

I had a tank that rusted through. It got an air leak from the rust pitting. You're on the right track - remove the rust and re-paint. Hope you're regularly draining your air tank, there's more rusting inside than outside. Kinda hard to repaint that :)

Karl

Thanks for advice! Yep, I drain it every day, I get between 1 and 5 litres of water out of it depending on the weather.

As an aside, the air tank was plumbed inline "after" my Air Dryer Unit and I got very little water (obviously) from the drain hose but I was told this was the wrong way to have it so I moved it to "before" the Dryer unit and now get loads of water (ie: compressor, air tank, then air dryer unit)... is this correct please?

According to what I was told when I had a new compressor-tank-dryer installed that is the correct sequence. Most of the water condenses in the tank and the dryer just 'polishes' it on its way to the machines. My system has automatic purge valves on both tank and dryer.

Regarding your rusty tank I don't think you have any problem just wirebrushing off the loose rust and painting. According to a couple of suppliers I dealt with compressor air tanks normally have a large corrosion allowance, or should have I guess because some cheap ones I have seen appear very thin. Corrosion nearly always localises and causes pitting which leads to pin hole leaks long before the tank as a whole is at risk. I don't think this applies to very high pressure tanks.

Since you have air available why not sand blast it, there are small inexpensive sand blasters out there. Afterwards paint the tank with a good epoxy paint.

Heh! didn't think of sand blasting! thanks! that would get into all the nooks and crannies like the leg bits that the tank sits on top of... just concerned about the compressor input sucking in some grit and wrecking the pump though... hmmm. Think I'll stick this on the "to do" list lol.

There should be an intake filter on the pump so you should be ok.