I am a compressor newbie, so forgive me if this is an obvious question. For years I have run an airbrush using car tyres. I would fill them at the servo, and then run the airbrush through them via a regulator. I now have a brand spanking new compressor with a 30L tank (bit of overkill for just an airbrush) to run it off. I have connected it up to the airhose, and used the old regulator so that I can have a regulator nice and close to where I am working - in case I need to make small adjustments to the air flow. I must admit I wouldn't have bothered with this, except that I had the regulator already hooked up to the airbrush hose. ANyway, that means there are now 2 regulators in the system - the one at the compressor, and the one at the working end of the hose. I cannot seem to get a consistent pressure at the working end regulator. It will start quite high, and gradually drop with time as the airbrush is used. It will start at about 50 or so PSI, and can drop as low as 10. The whole time there is not enough air drawn from the compressor's tank for the motor to kick in, so I don't think I'm using more air than the compressor can deliver. Back when I was using the tyres for air, I could dial up 22 PSI or similar and it would stay rock solid on that setting. Is there a trick to using 2 regulators in the same air line? Is it possible? Any ideas what I am doing wrong?

As with most regulated systems, you need to have an 'overhead' for the regulators to work properly, This means that the pressure at the inlet to the regulator (not the outlet of the previous regulator or tank) needs to be at least 10PSI above the expected outlet pressure of the regulator. If you persist with the double stage regulation approach, set the regulator at the compressor to its maximum pressure and leave it there, rather than letting it limit the input pressure to the second reg.

Assuming that the secondary regulator is working properly (I have had air brushes get grit in the air passages from operating from tyres in the past, so possibly this could happen to the regulator as well), I would look at setting up non regulated outlet at the tank and feeding the work area reg from that with a 8-10mm ID hose, particularly if the compressor is a reasonable distance from the work area.