My old 1990's era Sears Craftsman air compressor has been very reliable over the years. Now it is kind of old and I wonder if it is still safe to use. It is a horizontal 30 gallon tank. It has an oil-less single stage 125psi pump. When I drain it the drain seems to clog then clear. No crud comes out so I thought it may just be freezing up from the pressure drop. Not much moisture come out unless it is very humid summertime weather and it has been running all day. I see lots of scary compressor explosion videos online and also some simple DIY hydrostatic pressure tests. You fill the tank with water all the way up. Then put pressure on it either with a power washer or a grease gun filled with water [?!?]. The idea is that water will not compress so if the tank fails it won't explode no real harm done. You put about 150% of the rated load of pressure to see if it holds. I also see where when they open the plugs and run a garden hose inside- lots of rust comes out. Has anyone done this? Is it worth the effort? Or should a tank this old just be retired just because of the age? I also see that late model tanks have expiration dates now. So old tanks were better made? The manufacturer label welded on the side says the tank is actually a Campbell-Hausfeld. If I was to go ahead and test it I suppose the best way is to remove the compressor pump and stuff. Then open the main plug for a look-see. Heavy rust inside would condemn it right off. If clean then go ahead and do the hydro test?
