Paasche air compressor question

Hi all, tonight while i was painting my air compressor kept on turning on and off. For the last month I’ve noticed that the air pressure hasn’t been consistent going through the airbrush, is there something wrong with my compressor? Also the attachment that regulates the psi and that had the air release on the bottom seems to not fit correctly anymore. It has to be tighten and it doesn’t sit the proper way, when i tighten it all the way the psi gauge is upside down. Is there any remedies for this or should i look at a new air compressor?

Most likely, the seal between the tank and the regulator has failed. But no need to panic, this is an easy fix. The only thing you need is some Teflon Pipe Tape. Unscrew the regulator from the tank and remove. Clean any old tape off the pipe fitting and start winding the new tape on the fitting in a clockwise direction. Start winding at the base of the fitting and build up several (5-6 passes) layers of tape, gradually thinning the number of layers as you work towards the end of the fitting. This may take some trial and error to get the thickness of tape just right, so that when you re-thread the regulator back on, it tightens-up in the correct position with the water-trap facing downwards.

https://www.youtube.com/watch?v=niW6FuRBbHk

@paska thank you, I’ll give this a try. Is there any other issues that it could be? I ran the compressor without the regulator and just put the hose on and connected the airbrush. It still cut on and off without the regulator on it. Also the airbrush had a flow but when i took off the aircap that covers the tip the airbrush had a strong pressure, when i replaced the aircap the pressure went down. Any reason for this?

The cut-off: The power on/off turns the motor on when the pressure drops below the lower pre-set value and turns the motor off when the pressure reaches the upper pre-set.

The pressure regulator: Converts the pressure from the tank/compressor down to a value set by You (turning a dial, knob, lever, whatever).

Without the pressure regulator the compressor will push air down the hose until the resistance in the hose and airbrush has built up the pressure to the upper cut-off, the motor stops and the pressure drops until the lower limit kicks in and starts the motor again. The compressor will cycle between starting and stopping at a fairly rapid pace depending on the resistance in the hose. A high resistance will cause rapid cycling and a low resistance will keep the motor running continuosly. In this case the hose acts as a secondary tank with a very low volume
The airbrush cap probably changes the resistance which affects the cycle rate.

As paska wrote you may need to use pipe tape, especially after removing the regulator since the old pipe tape that might have been there has been shredded by removing the regulator. Pipe tape needs to be replaced almost every time.

It could also be that the regulator has aged and broken down. They don’t last forever, mine was giving me issues and I kept eradjusting it and then it broke down completely and had to be replaced.
This type of regulator is a more or less standard item, as long as you make sure to get the same pipe/thread dimensions.

@Robin_Nilsson im going to use the tape today and reattach the regulator. I think you guys are correct, it has to be the regulator it’d make the most sense in this situation. I’ve had it for two years now! I also wonder if because i have bought extra air caps and tips in various sizes if maybe even thought the aircap and tip are the same size they may hit be the correct match. As in i bought a set off Amazon and i have the original set, if i use the original set tip with the Amazon cap would that booger it up even though they are supposed to be interchangeable. I find this very unlikely but don’t want to rule it out as a reason airflow is lacking?

Airflow should be constant and controllable even without an airbrush attached to the other end of the hose.
The regulator shall deliver a constant, or close to constant, flow at the preset pressure. Minor variations might occur just before the compressor starts up.
Variations should be minimal since the pressure regulators are usually set to have the tank between 6 and 8 bar, or 87 and 116 psi. The “normal” pressure used in AB’s is usually below 2 bar or 29 psi. In most cases 20 psi or lower.
The 87 psi in the tank should allow the regulator to give you a constant 20 psi out of the hose. The motors work cycle shall not affect the outgoing airflow (unless the regulator is worn out …)

When you change out the air caps and tips, are you changing the corresponding needles as well? All three need to be properly matched together by size number or chaos will ensue. I have a Paasche VLS and I have had lots of fun :dizzy_face: trying to keep it in top operating condition. Then Paasche redesigned the entire assembly of these parts, (Tip size #1) for this model AB and when I ordered replacement parts they looked nothing like the ones I was replacing, so I sent them back thinking I received the wrong parts. :confused:

1 Like

Mismatched caps, nozzles and needles is a major “oopsie” :laughing:
Chaos is definitely a suitable expression :rofl:

Yep! And I haven’t even mixed them up…yet. But I am an expert at mangling needles! :zombie:

So good news, i just needed to tape the threads for the regulator. I did a test run at 20 psi after this and head perfect air flow.

  • when is comes to the needles i make sure everything matches, what i mean with the air cap and needle points being different is i have the original tips and caps, but may use a needle that will fit those but it wasn’t from the set. As in sometimes i think if it’s not all from the same set it maybe starts acting up.

  • thank you everyone for the help. Saved me $$ as i was about to go look for a new compressor today.

May be a dumb question but I’ve never encountered this, is my compressor supposed to automatically turn off if the airbrush isn’t continuously running? It’s only begun doing this yesterday? I’m assuming that’s the automatic turnoff in effect

I’m assuming that you have a compressor with a tank.
The automatic on/off will make sure that the pressure in the tank is kept between 6 and 8 bar (87 to 116 psi).
When the compressor has filled the tank to the upper limit the pressure switch will shut it off.
When air has left the tank so that the pressure has gone dow to the lower limit the pressure switch will turn the motor on.
If the compressor can pump air faster than you can consume it the pressure switch will keep turning the motor on/off.

The fact that it turns off is sign of health.
On the other hand, there IS a problem IF the pressure switch turns the motor on when you are NOT consuming any air. This means that something is leaking somewhere. If the leak is in the airbrush, a hose, a connection or in the pressure regulator then it will be relatively easy to repair/fix.
If the tank is leaking then there is real trouble. Getting a new tank can be difficult …

Did the shut-off behaviour start AFTER you fixed the attachment of the pressure regulator?

@Robin_Nilsson no the shut off occurred prior to me fixing but it was the first time it had occurred ever which caused me to panic

I usually had a semi-panic when I was totally focused on the airbrushing and the compressor suddenly started … aaannnnd it is a silent one …

The pressure switch on my compressor lets out a PSSSCCHHIIIiiiii when it shuts off, also somewhat startling

1 Like

@Robin_Nilsson glad to know I’m not the only one who gets panicked when there’s something we’ve never encountered before