I have a Sears 2HP/20Gal mobile air compressor that I bought new about 25 years ago when I was a teen. Note that back then, Sears compressors were not sold with over-rated HP claims: mine has a 2HP/15Amp USA-made, Century Motor by Gould Inc.
Even though I've always kept it topped up with air compressor oil, it has succumbed to wear and tear (I admit, I've demanded much more air volume from it that it's capable of delivering, particularly when sandblasting). It now blows a small amount of oil into the tank. Not enough to significantly diminish the oil level in the crankcase, but enough that a milky yellow oil-water emulsion is blown out of the tank drain daily. I can live with a little compressor oil in the air when operating air tools, but it wreaks havoc on my sandblasting (yes I do have a coalescing filter and drain it regularly, but some oil/water is still getting by, especially when blasting for any length of time).
The problem is, replacement parts from Sears are outrageously expensive (at a minimum $75, and perhaps quite a bit more because it's not clear if their ring "kits" include just one ring or a set).
Frankly, if I'm going to spend the money, I'd rather buy a large vertical-tank stationary compressor, but I don't have the space for one now (and with a baby on the way, it's out of the budget).
Any ideas on solving this problem without dumping a lot of money? Are generic rings typically available for compressors (and if so, how do I find the right ones)? Would honing the cylinder walls help? Would a better air filter solve my problem?
Thanks, Michael