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Pressure is on

bearman

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I have talked with several people about the air pressure and can't get a straight answer from anyone on what pressure to use for the primers to top coats. Some use low and others using high. Would 40 psi be a good point.
 
I think its sort of a preference thing, and depends on exactly what primer you use and how you reduce it. I think about 30psi is standard. You want just enough pressure for proper atomization but having too much pressure will cause problems.

You can fine tune the pressure until you get the best results.

Depends also on if your doing detail work, you would turn down the pressure and/or simply press the trigger very lightly. The pressure works together with other factors such as spray distance and tip size, etc.
 
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Like Evan posted.
I run 20 to 30 psi out of the gun reg depending on product sprayed and temp and also the gun itself and tip size.
Most times I go more by pattern and sound lol. Always test pattern your gun when starting. Use a sheet of masking paper on the wall.


Should also add many times the compressor cycle itself will dictate what you have to use for a pressure setting.
Prime coats not such a big deal but once you go to paint you want to play with the bottom and top of the comp cycle to see what you got for volume ect.
 
I start with what the tech sheets says for the product. There’s not one pressure for everything.
 
Hvlp gun just getting started. Need to spray exopy.
 
Hvlp gun just getting started. Need to spray exopy.
Follow the tech sheet for the brand of paint you are using. Set the gun up using the instructions that came with gun. Look on line there are set up instructions there. Do several test spray patterns with gun adjustments and different air pressure. this should get you close. Now practice.
 
Bearman, I don't paint the color ever but i do my own body work and primer. I 've had great luck with Harbor freight 's" Purple gun" ,cheapo regulator and water separator. I turn my compressor down and adjust the cheapo reg. that is attached to a water seperator that is attached directly to the gun to 28 psi. When i pull the trigger the pressure drops to 20ish. I have no idea if the psi numbers on this crap are correct or not but that's where i start and then play with the flow from there. I' m all in for about $25 bucks ,i do have a back up gun ready ($15 insurance policy).
 
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Having a constant steady psi is critical , with the topcoats. I use cheap guns, but I bet the pros will say each brand of (good) gun is different. Checking or pattern is the ultimate key, and every things sprays different.
 
Most people just get feel for what works best for them and stick to that. Use the tech sheets, ask the paint manufacturer if you need to or are worried. Most people who shoot auto paint all day are not obsessing over the psi. They just adjust the gun until its sprays how they like. Once you've done it enough times you might not even use a pressure gauge, I don't, and I would say most proffesional painters don't either.
 
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