Technical details about compressor

[pisoiu]

I plan to buy a compressor in the near future but I am unsure about some technical details. Now is the time to gather as much information as possible and to ask some questions:
-sometimes I see paintball compressors for sale. Is such compressor suitable for scuba, I do not know if they produce breathable air ?
-the compressor will be more likely second hand, no funds for a new one. What to look for or what to ask the seller? Buying from ebay may be a sollution (and a gamble, I know), but at least I have to ask the seller the right questions.
-perhaps in the future I will try to mix nitrox, whatever cheap method there is, no more than 40%. I can obtain O2 in high pressure cylinders (40 or 50 liters). I don't have tanks O2 cleaned, so it won't be partial pressure fills. Is there any restriction to the compressor?

Thank you.

 

[Wookie]

The difference between a paintball compressor and a scuba compressor is filtration. You must have a moisture separator and filter tower on the compressor, sized appropriately, with the correct filter. It is easier on you to have auto drains, but as long as you drain each moisture separator every 10-15 minutes, you'll be fine if it has manual drains. Ask the seller how many hours, ask the seller how often he changes the filters, and ask the seller to see the maintenance records. If the seller can't produce maintenance records, then the likelihood that he actually did maintenance is not so good. Compressors need the oil changed every 250 hours or so, and in the humid environment of a boat filters need to be changed every 25 hours. That type of thing must be recorded. You need to see the compressor run. If the seller has unhooked it from wherever it was set up, you still need to see it run. No exceptions, unless the exception is he lets you take the compressor without paying for it until you hear it run.

If you're going to CB nitrox, you might plan on completely rebuilding the compressor air parts (rings, pistons, liners, valves) wetc before you start. If you don't, you're going to do it after. Plan on it. You need to make sure that the compressor has synthetic oil in it. Again, that's part of the maintenance records. Paintball compressors will likely have mineral oil, it's cheaper and works better, but not for breathing air/nitrox.

Tghat's a start. There are some much smarter folks than me here that will help you further.