Has anyone had any experience using airbrush air compressors. I'm looking at a as186k model. It is designed to turn on/off when needed. My question would be could I have it plugged in and turned on attach the hose line to a solenoid valve which can be controlled by the arduino to say how long the valve were to be open for? If so would I just need a transistor to control the 12v solenoid valve?
That doesn't make any sense.
The compressor turns on and off by itself in response to the air pressure in its tank. If you use a solenoid to control the output when & where you want, you don't need to control the compressor. It will come on by itself to fill up the air you've used.
What are you trying to do?
My reading of the OP is that he has a compressor that he wants to use air to feed a solenoid to drive some external device. The compressor has its own pressure regulation control.
You can use a transistor to drive the air control solenoid.
Weedpharma
Sorry maybe I wasn't very clear.
If the compressor is on it will only actually turn on if the tank psi is below 43psi OR if the air is being called for. I figured I could regulate the call for the air via a solenoid valve. I'm just after a short air burst for effect not to drive anything.
Or would I be better off putting in some sort of switch to turn on the unit at the beginning of the loop and then use the solenoid valve to call for the air when needed and have a switch to turn the units power back off again at the end of the loop.
Turning the compressor on and off is probably not the best idea unless you only need the air burst once occasionally.
If you have a need for air on a regular basis, turn on the compressor when you need it and leave it until you no longer need it.
Control the air burst with an air solenoid driven by a transistor or MOSFET.
Weedpharma
The compressor would probably be needed for 3-4 hours but only a short burst of air every couple of minutes throughout that period. I think I will manually turn on the compressor at the beginning and then use the valve to control when the air is released. That way I won't have to mess around with connecting into mains power as I'm guessing the solenoid will be a 12v.
Cheers for the help Weepharma
Greg
What actual pressure are you trying to control.
I ask because most solenoid valves require a minimum pressure of about 10 psi to function correctly.
I would be running it at least 20psi ideally higher 30-40psi to give me a nice air blast to startle someone 
I have heard that reticulation solenoid can be used as well. I have not tried it. They may be easier to use in a non critical air burst.
Weedpharma
Google "Airtac 3V1-06" and look for a 12V version (needs DC 12V to operate). The -06 part means it will have 1/8" NPT fittings. I guess I'm assuming everyone lives in the US 
The words Boardburner2 was looking for were "pilot operated" (as opposed to "direct acting"). Pilot operated valves need a minimum pressure before they budge. It helps cut down the current needed to actuate the valve.
If you're looking for something locally try a car air horn solenoid which you might be able to get through an auto parts store. I think most air horn kits just actuate by powering the air pump but I know that solenoid valves exist as well.
if the compressor has a pressostat you will need a solenoid valve and a mosfet or relais.
another relais can be used to switch on the compressor.
Chagrin:
Google "Airtac 3V1-06" and look for a 12V version (needs DC 12V to operate). The -06 part means it will have 1/8" NPT fittings. I guess I'm assuming everyone lives in the USThe words Boardburner2 was looking for were "pilot operated" (as opposed to "direct acting"). Pilot operated valves need a minimum pressure before they budge. It helps cut down the current needed to actuate the valve.
Direct acting valves are very seldom used these days, for reasons you have given , high current.
Tend to be pricey too.
Only time i ever needed one was for a low pressure clamp using bellows
Chinese knockoffs of pilot operated valves are very reasonable
Would this work?
Would I need anything else to wire it up?
As we were talking about before, that pilot operated valve needs a minimum 1.5kgf/cm2 (21 PSI) to operate. As long as keep your pressure above that minimum it'll work fine.
See http://bildr.org/2011/03/high-power-control-with-arduino-and-tip120/ for how to wire it up. You do need the diode. The coil will need 250ma.
Cheers for the link that really simplifies things. As for the valve if pressure dropped below 21 PSI what would happen? would it stay shut until enough pressure was built up? if i let out pressure for too long it may empty the compressor tank and then the compressor will kick in to refill. that would be fine as i will only be calling for the air for about 500milliseconds every couple of minutes
im guessing i would need a seperate transistor for each solenoid im using?
Yes, per the spec the solenoid will not move until your pressure goes back to 21 PSI. And yes, you will need a separate transistor for each solenoid you're using.
gregbarnard:
Cheers for the link that really simplifies things. As for the valve if pressure dropped below 21 PSI what would happen? would it stay shut until enough pressure was built up? if i let out pressure for too long it may empty the compressor tank and then the compressor will kick in to refill. that would be fine as i will only be calling for the air for about 500milliseconds every couple of minutesim guessing i would need a seperate transistor for each solenoid im using?
yes transistor for each valve
21 psi is needed to operate the valve once operated it should stay in that position.
if below 21 psi it may not operate to active position though.
if its a short burst controlled by the solenoid I see no reason why it would fail.
I have a dispensing system that works like this.
short bursts of solenoid controlled pressure.
compressor only runs when resevoir is depleted.
Thanks now I have to wait for my order from China as UK stockists were extortionate
HI there! Thank you for the thread here. I am a newbie. Just got my first compressor kit from store in Louisiana. I am interesting in such control too. Thanks again, bookmarked it
@roterio what are you trying to achieve with your compressor?