Vacuum Pump converted for Airbrush

[Ken Loy]

I'm trying to make my vacuum pump into a compressor for a new airbrush but running into complications. Is it a fools errand?

I've run a hose from the outlet (pressure) of the vacuum pump into a regulator and then to the airbrush. The problem I'm running into is that the vacuum pump runs continuously and there's no relief for the pressure that builds up between the pump and the newly added regulator. I would imagine that a cut-off switch installed to turn off the vacuum pump when the outlet pressure builds up, or install a relief valve that I'd manually adjust. Or perhaps some of you have a set-up that works differently.

Thanks for your ideas.

 

[Brent@TurnRobust]

What we use for vacuum pumps are often used as small low-pressure compressors. For instance, they are used for aerating a pond. Depending on the pump, running continuously when no air is moving may be perfectly OK. Check it to see if the pump is getting excessively hot. If you're running cool or even warm, you probably don't have a problem. If it's getting hot, you may need a Plan B. I think if you're using one of the vacuum pumps that uses oil, like those used in refrigeration, you may get extra oil mist doing what you're doing.

 

[Dave Landers]

I run my airbrush off the shop's air compressor (with a regulator in-line with the airbrush).

You need to keep the pressure into your regulator above the regulator's setting - otherwise you'll have pressure fluctuations at the air brush. So either let the pump run continuously or else have a tank and cut-off switch between the pump and regulator. The tank will smooth out the pressure when the switch cuts off.

If you go the tank route.... By the time you find something for a tank (old propane bottle, freon tank, something else similarly sketchy - or else obtain an actual portable storage tank), add the pressure cutoff switch, plus whatever valves and fittings needed... you might as well buy a small inexpensive pancake compressor. If noise is an issue, you can run it to charge the tank outside and bring it in for the job. The air in its tank will probably last a good long time for just an airbrush.

 

[William Rogers]

This is my setup. I do have an off on toggle valve. Basically a switching valve with A and B outlet. I plugged the A outlet that shuts of the air. The needle valve is for my dentist drill setup and not needed for an airbrush. I can run off my vacuum pump pressure side or my air compressor. I have a Thomas vacuum pump (oilless) and it can run 24/7 continuously. However I always use my air compressor.

HD means I got it from Home Depot and HF is from Harbor Freight.

 

[Gary Beasley]

Cheapest route is to put a bleed valve in line so you can dump excess pressure and also carry away the excess heat. If you have a pressure gauge on the line it should be easy to set the pressure to a bit above the regulator setting. A spring loaded overpressure valve would be even better as it would close if the pressure drops beyond a set point.

 

[Richard Coers]

If you start to build anything, you must know the engineering details on how that something works.