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I have a 1/10 HP compressor that I have been using , and I just replaced the pressure gauge that I had on it with a higher span guage. The new gauge goes to 100 psi(6.9 bar). the old gauge only went to 30 psi(2 bar). The old gauge would max out at 30 psi so I thought I was fine on pressure. With the new gauge, the pressure still goes to 30 psi, but it will drop to about 10 psi (.7bar) when I start to spray.

My question is, does it matter if the pressure drops to 10 psi while I am spraying? Or should my compressor be powerful enough to maintain 30 psi while I am spraying. I do notice a drop off in air pressure out of the nozzle from when I first start spraying as well. It's basically a burst of high pressure air then down to a lower amount of air flow, which is consistant with what the gauge is showing as well.

Any advice?

Also I don't have an air tank yet.

GG

Does your compressor have problems keeping the psi up or does it continue to fall? My gun/airbrush are specifically made to continually spray most airbrushes/ compressors from my understanding are built for burst spray. It's been years since I used my airbrush though because it was really only useful to me for basecoating as I never practiced enough to do any sort of detailed work whatsoever.

It will fall to 10 psi and stay there, until I release the trigger. Then it will go back to 30 psi.

GG

Your average hobby airbrush is designed to work at appx. 20psi max. The pressure should start at 20-30psi with no load (not spraying) and drop to about 15psi when is use. Just sounds like your compressor is getting old and the load pressure has dropped to 10psi.

If the paint is still spraying evenly I wouldn't really worry about it, but you could always pop it open and see if any seals or O-rings could use replacing to beef the pressure back up.

BTW, a trick we use to even out pressure when we're running multiple aquarium airlines off 1 compressor is to build a cheap air reservoir out of a 48oz apple juice can.
You just rinse out the can and let dry, then epoxy two airlines to the holes for inlet and outlet. Then you run the compressor line to the can, and run your output line from the can to your airbrush. This way the compressor only has to work on topping up the can pressure instead of feeding the airbrush directly and keeps your pressure up much better without wide fluctuations.

Hope that helps you!

if it doesn't have a tank then the pressure will fall (as you use the air). tanked compressor's can keep the presure steady.

As the two previous postes have mentioned, you need an air tank if you want to keep really consistent pressures. Personally I wouldn't much worry about it if the pressure is enough to put on a smooth coat of paint.

Thanks for the help. I was thinking it may be an issue of not having an air tank. The compressor isn't new, it's about 9 yrs old. I was considering getting a new compressor/tank combo anyway. But sticker shock has been keeping from purchasing a combo.

Thanks again,
GG

Most airbrush compressors I've seen have a small tank or bottle (the compressor is used to charge the tank, not to run the brush. The brush runs off the tank) to remove this issue.

My own compressor is a 240v compressor meant for inflating tyres and stuff. It's mated to an old oxy bottle, pressure regulator and moisture trap using standard fittings. It was a bit of work to put together, but it was cheaper than the $400 I was quoted at the time, and though the compressor is noisy, it only runs to charge the tank.