Air compressor: rust inside is plugging drain valve

[thool]

I have a Husky oil-less air compressor that is about 12 years old, it lives in my garage, and I use it about 2 times a month, and a lot more in the warmer months. I've replaced the drain valve twice, because eventually they get jammed shut with rust.

Today when I removed the non-functional brass drain valve, there was a rust plug inside that held back 60 PSI. I was loosening it under pressure to purge rust by pressure. A screwdriver broke the seal and the rust plug shotgunned out.

So what is the best way to prevent this? I've drained it every use, but the rust seems to breed in there. I see a big access plug on the side, size of a beer can, and the bottom has a similar plug. Can the inside bottom be painted or otherwise sealed?

 

[JJThrasher]

I'd replace the drain with a ball valve. I did that on my compressor and haven't had an issue with it. You shouldn't really be getting a whole lot of rust if you're draining every use.

 

[CNGsaves]

Severe rust can be prevented by draining water DAILY.

+1 to install length of black pipe steel for your drain with a ball valve.

For "repairing" the interior condition of tank, yes it can be cleaned out and painted like you would a rusty motorcycle tank, or when you convert a LPG 20 gallon BBQ bottle to portable air tank. See YouTubes.

 

[jmarkwolf]

If you're getting that much rust out of it, I'd be concerned about the tank rupturing!

There is a thread on this website about just such occurrences.

It opened my eyes.

 

[Richard Cranium]

Tank rupture would be my concern also.