Recomendations for Air-Powered Sprayer

May 15, 2014 6:14 PM

I'd like to pick up an air powered paint sprayer, but I'm not sure what I should be looking for as far as specs or brands. I already own this PORTER-CABLE CMB15 150 PSI 1.5 Gallon Compressor. The main uses for this sprayer would be painting & spraying clearcoat on furniture and other woodworking projects. If the same sprayer can be used to paint a room or an outside barn, all the better.

So my questions are:
* Any specific recommendations?
* If not, what should I be looking for as far as specs?
* Also any additional accessories (besides a respirator obv.) I keep seeing Oil / Water Separators, as well as pressure regulators popup in related links & reviews. Is that something that's needed.
* Any resources you can recommend to familiarize myself with this subject.

posted by pyro979 to Home & Garden (4 answers total)

That compressor isn't large enough to run anything bigger than an air brush. Two actual horsepower (IE: it should draw 12-15A at 120V when running) should be considered the minimum to run an air hungry, large duty cycle tool like a spray gun. Preferably with a large tank to help allow water to condense.

Oil/water separators are needed but they only get the liquid water. Compressing air allows it to hold a lot of water vapour so you need some way to actually dry your air (radiator, desiccant, refrigeration) for best results.

You'll need a pressure regulator though depending on your gun the tank regulator may be sufficient. A regulator immediately before your tool will let you set a more consistent pressure though that can be easier to paint with.

This guy has a pretty good intro to spray painting and air supply aimed at home car painters.

I've never used one but some HVLP guns have built in fans that allow you to spray without an air supply. These are something different than "airless" sprayers which use pressurized paint to atomize the spray.
posted by Mitheral at 6:40 PM on May 15, 2014

For clearcoating on furniture, my impression is that you absolutely want an HVLP (High Volume, Low Pressure) system, which includes the air source. I use wipe on finishes for all my furniture building, so I don't have specific recommendations, but if I get to the point where I can justify going spray, HVLP is definitely the right way to go.
posted by straw at 7:51 PM on May 15, 2014

Mitheral's right about your compressor. There are lots if inexpensive HVLP "conversion" guns that are compressor-driven (as opposed to the expensive fan-driven type) which can be used with a relatively small compressor, but a 1.5 gallon model isn't going to cut it. There are LVLP guns too, which I haven't personally used, but I suspect even they might need more air than your compressor can deliver. You can get away with a lower-power machine when shooting finish on furniture and other modest-scale woodworking projects IF the underpowered compressor has a big tank so you can let it take its time to accumulate a big charge, but a compressor that can't keep up with the gun's demands in real time and also can't store much air is just not going to work.

Furniture finishes use a much smaller spray tip than would be required for shooting heavy paints for rooms and barns. It's also difficult to get the gun thoroughly cleaned after using pigmented paints, so you can end up having unwanted residual color contaminating later clearcoats; it's best not to try to use one gun for both purposes.

Unless you're shooting nitrocellulose lacquer, which is especially moisture-sensitive, I doubt you'll need to worry about fancier air driers.
posted by jon1270 at 8:00 PM on May 15, 2014

Oh, and spraying will require a pressure regulator but it looks like your compressor has one built-in. If the compressor itself was up to the task, you'd be set.

Here's an LVLP gun, from a company that makes inexpensive but pretty good spray guns. I have one of their older HVLP guns. Anyhow, it requires up to 9.8 CFM at 25 PSI. That's solidly more than your compressor can keep up with. If you're finishing objects bigger than a jewelry box, plan on getting a bigger compressor.
posted by jon1270 at 8:11 PM on May 15, 2014