The thread kind of took a turn...but back to the OP's question about those Chinese $400 compressors. My opinion is "NO WAY". I recently did a visual inspection on a tank that was being filled by one of these (gold prospector, who used it in rivers at no more than 3-4 ft depth) The tank interior was coated in a paste that looked and felt like silicone grease. After a conversation with him, we agreed it couldn't have come from anywhere else but the compressor. I don't have any information on the brand or type of lubricant it used but WOW! Coltri MCH6, Bauer Jr. or MaxAir 35 would be the smallest I'd ever consider for your needs.