dwc43 Posted January 23 Share Posted January 23 I have a Central Pneumatic compressor. I got it a few years ago. It said it had a regulator and that's misleading from the start. It has a power cable that comes out of the back and goes into a valve that screws into a brass fitting in the back of the compressor head. IT's set for 4kg which is about 57 psi. I installed a CP regulator with water trap on it. If I recall correctly when I first tried airbrushing it worked fine with this regulator. I guess I had beginners' issues with painting by airbrush and set it aside. So, not I got it back out and want to learn how to use it this time. The regulator broke under the plastic adjustment knob. So, I bought one online exactly like the one that broke while in storage. Here's the problem. When the compressor runs wide open it cycles off at about 50 or 60 psi and cycles back on around 35 to 40 psi with no load. It will hold 30 psi with my dual action turned wide open, no paint, and regulator wide open. My dual actions says run between 12 to 30 psi. If I turn the regulator down to try and reach just 30 psi, it won't hold the spring-loaded trap closed on the water trap. Even if I hold it closed by hand, it won't build any air pressure and it runs wide open. Once I turn the regulator back up it runs fine but too high a pressure and it starts cycling again. Is this a faulty regulator, not enough volume from the compressor, compressor bad, I don't know. And if I recalled correctly, why did it work fine with the old regulator. Thinking about taking the new regulator out of the system and getting one of those brass valves with the gauge in it like the ones on my professional Binks guns that we use for painting race cars with. All it does is manually restrict airflow by closing off the air supply in the line itself with a gauge on the other side so you can tell by how much you closed it off. Any ideas why that compressor won't work with that regulator will be much appreciated. Quote Link to comment Share on other sites More sharing options...
Bainford Posted January 24 Share Posted January 24 It's hard to say without knowing more about your regulator. A photo or model number would help. However, I get the feeling you may have a regulator that is not designed to work at the low pressures used when airbrushing. Regulators used for shop tools, etc, do not regulate pressure accurately (if at all) down to airbrushing pressure. What is the range of pressure on your regulator gauge? Look for a regulator designed specifically for airbrushing. It will regulate pressure accurately within a range of 10-40 psi or so (and will often have gauges that max out at 60-70 psi). Don't buy it at Harbor Freight, etc. Good, accurate regulators are available from the online airbrush shops and can be had at a decent price. If you are diving into airbrushing, you can save yourself a lot of headaches by ensuring you have the right gear. With airbrushing, there are plenty of variables to get your head wrapped around, and when trying to sort painting issues (and there will be some) it is a huge help to know your equipment is not one of them. When buying an airbrush regulator, be sure that the inlet pressure rating of the regulator is at least as high as the output of your compressor. If it isn't, you may have to retain your current regulator to regulate the pressure to around 60 psi or so, then install the airbrush regulator downstream from that. Quote Link to comment Share on other sites More sharing options...
dwc43 Posted January 24 Author Share Posted January 24 (edited) Thanks for the reply. That's a pic I grabbed from the web of the compressor. And the specs they posted. Air Brush Compressor Voltage 120 V Lubrication Type Oil-Free Horsepower 1/5 HP Maximum Working Pressure 30 PSI Look at the compressor and you will see the built in regulator just under the fold down handle. That's the one that's causing it to cycle off when it hits 57 psi or so. That's factory set and not adjustable. That's a pic of the regulator that I bought. It looks exactly like the one that was on it and got broken on storage. I'll check the label on it later tonight. It does look like it has a part number and I want to check the max pressure for it too. It does say it's labeled for 145 psi max. I placed that regulator I bought between the compressor and water trap with gauge you see in the pic. When I had it set up before I stored it, it worked fine as I recall. I think it broke because it was left screwed down to a low-pressure setting. The entire top of the reg is plastic and it has a huge, stiff spring in it between the diaphragm and the adjuster. I think it got brittle and broke the top or it could have taken a hit and broke that way too. Not sure. I used a different air brush when I tried this before. I painted a hood that looked about as real and crappy as the paint on the real car did. lol But I did a body that looked like mini orange peel sort of. And I tried a metalic paint on one car that looked good in some places and not in others. Even though the paint was mixed really well, I just don't think the metalic sprayed like it should. Too much metal flake in some areas compared to others was the issue. Unless you need a smaller needle to make a bigger hole in the air brush for metalics, I blame the paint on this one. Edited January 24 by dwc43 Quote Link to comment Share on other sites More sharing options...
Bainford Posted January 24 Share Posted January 24 Ok, that helps. A couple of things that I didn't realise before. I see you do have an airbrush type compressor, and with a maximum output of 57 psi you won't have to worry about the max inlet pressure rating of any new regulator. The other thing I misunderstood was calling it a CP regulator. In industry, CP refers to Chicago Pneumatic, and very highly respected maker of industrial pneumatic equipment. Your regulator is Central Pneumatic, which is likely a cheap Chinese knock-off. This notion is supported by the almost complete lack of technical information online. The cycling off & on seems odd (to me) for a tankless compressor, though perfectly normal for a compressor with tank. I just had a look at the manual and it is in fact working properly, with auto shut-off at 58 psi and restart at 43 psi. So, the cycling is perfectly normal. I'm not sure how this will perform when airbrushing without a tank, but the cycling pressure range is perfectly workable for airbrushing. I think your regulator is indeed too heavy duty for airbrushing. During my quick search I couldn't find it's designed working range, but being fitted with a 160 psi gauge suggests it is probably intended for industrial use. I would recommend getting a regulator intended specifically for airbrushing. Get a good one, and make sure it has a built in moisture trap. That will get your pressure settings corrected. I would also strongly recommend fitting a small tank or air pig between your compressor and the regulator. This will reduce the frequency of the on/off cycling, and airbrushing from a tank is much smoother and easier, allows the airbrush to work with the precision it was designed for without the pulsating air supply directly from the compressor. So, it seems to as though the compressor is suitable for the job and working properly, and that your current regulator is either duff, or just the wrong spec for airbrushing. Quote Link to comment Share on other sites More sharing options...
dwc43 Posted January 24 Author Share Posted January 24 Thanks for the help. I'll check out your suggestions and see if I can make it work for me. Quote Link to comment Share on other sites More sharing options...
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