lasermonkey Posted August 31, 2021 Share Posted August 31, 2021 (edited) Hi, over the past few months I have noticed something amiss when I'm airbrushing. Basically, the regulator doesn't seem to be able to maintain pressure. I know the compressor is cycling between 30-40 PSI, but whatever I set the regulator to, it quickly drops to almost nothing when I depress the trigger on my airbrush. It recovers quickly when released, then drops again when I spray. It seems to have got worse over the past few weeks to the point where it's basically unusable. I can't detect any leaks and when the regulator is wide open, it pretty much tallies with the gauge on the compressor. It has to be the regulator, right? If so, is there anything I should check for, or should I just get a new one? Thanks in advance for any advice. Cheers, Mark. Edited September 3, 2021 by lasermonkey Changed title. Link to comment Share on other sites More sharing options...
Stew Dapple Posted August 31, 2021 Share Posted August 31, 2021 Hi Mark, Does it have an air tank, or is it an 'on-demand' compressor? If it's the former, there is a screw-valve on the bottom of the tank to drain any water that has condensed in the tank due to the effects of air compression - Jamie was kind enough to advise me of this and it returned my compressor to it's former abilities. If it's not a tank compressor then I've no idea I'm afraid. Cheers, Stew Link to comment Share on other sites More sharing options...
lasermonkey Posted August 31, 2021 Author Share Posted August 31, 2021 Hi Stew, the compressor* has an air tank and the regulator is separate, being in-line between the tank and the airbrush. I have bled the tank via the drain tap at the bottom, just as a precaution. Unfortunately, nothing has changed since. I also tried my other, diaphragm compressor (which has a very small tank) with the regulator and the problem persists. I’m guessing I have answered my own question now……. Cheers, Mark. *the compressor is an ancient de Vilbiss contraption from 1958. It consists of a pump, a tank (with pressure gauge) and a pressure sensor which switches the pump on and off. Despite being old and cumbersome, it has been reliable and is quiet enough to use at any hour. 1 Link to comment Share on other sites More sharing options...
Dave Swindell Posted August 31, 2021 Share Posted August 31, 2021 Sounds to me like there's a partial blockage in the pressure regulator - there's enough of a gap to let the pressure build up when there is no flow, but not enough to maintain the pressure when in use, probably dirt rust congealed oil or a combination of all 3. Vent the compressor tank, remove the regulator, strip and clean then re-assemble. There's not much to them, valve, diaphragm and spring in most cases. 1 Link to comment Share on other sites More sharing options...
lasermonkey Posted September 1, 2021 Author Share Posted September 1, 2021 I had another look at the regulator tonight. It's a Wilkerson 50-054, if that means anything to anyone! The only thing that looks like a possible way in is a large nut located at the base of the control knob, underneath the plastic fixing nut. Unfortunately, I don't think I have a spanner big enough to fit, though I'll have a look around the house tomorrow. I think I might just get a new one though. Link to comment Share on other sites More sharing options...
Jetblast Posted September 1, 2021 Share Posted September 1, 2021 The guts are accessed from the top - remove the big nut & there should be flats on the threaded section, remove the threaded section to get the gubbins out. The guts might spring out when the threaded section is released, so keep some pressure on it when it runs of the threads. Clean the seals, spring & bore in hot soapy water, dry, lubricate with white grease & reassemble. Check that the seal/s are intact & take care when removing the threaded section as the plastic may have become brittle. Link to comment Share on other sites More sharing options...
lasermonkey Posted September 3, 2021 Author Share Posted September 3, 2021 Well, the new regulator arrived today and guess what? The problem hasn't gone away. To reiterate, the compressor is an old deVilbiss (which comprises motor, pump, tank (probably 5 litre and is vertical) and pressure switch. On the output there is a pressure gauge situated just before the tap. The compressor cycles between 30-40 PSI. There's a hose which connects the compressor to the regulator, and when wide open, it tallies with the reading on the compressor gauge. This then connects via another hose to the airbrush. When the airbrush trigger is depressed, the spray pressure drops a small amount on the regulator gauge (as you'd expect) momentarily, then drops down to barely anything. When the trigger is released, the pressure comes back again within a second or so. I've tried two regulators and two airbrushes and I don't know what to do now. I did find my way into the original regulator (which looked spotless inside, but I cleaned it anyway) but the problem persisted, meaning there was probably nothing wrong with it in the first place. There aren't any leaks that I can detect. As the tank is pretty large, you get a fair amount of time when the compressor is off, so leaks would be quite audible during that time. I have filled and bled the tank several times. There was some oily gunk that came out, but that has cleared now. I'm flat out of ideas! I can't think what might be happening. Cheers, Mark. Link to comment Share on other sites More sharing options...
Jetblast Posted September 3, 2021 Share Posted September 3, 2021 Might be worth checking that air is flowing freely through the hoses you have & that there is no kinking or restriction in them 1 Link to comment Share on other sites More sharing options...
lasermonkey Posted September 3, 2021 Author Share Posted September 3, 2021 Thanks @Jetblast. I have replaced the hose from the regulator to the airbrush (it’s an Aztek airbrush, and I had a spare) but I’ll need to buy a replacement for the tank-regulator hose. That one’s a good 30+ years old and has seen better days. I’ll let you know how I get on. Link to comment Share on other sites More sharing options...
lasermonkey Posted September 8, 2021 Author Share Posted September 8, 2021 Well, the new hose has arrived and the problem has been sorted. Many thanks to everyone who helped. It’s much appreciated. Best regards, Mark. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now