HVLP, pressure confusion, where to set?

[chrisl]

I'm confused how to set pressure on my HVLP. Its a Devilbiss HVLP gravity feed, 1.3tip, and I"m shooting acrylic single stage color. Our compressor regulator is set to 100psi. Hose and fittings are 3/8 through-out.

On the gun itself, I have a devilbiss gauge and regulator. Can I leave the compressor as is, and just set the gun regulator to my desired pressure? The p-sheet says 7-10psi, so do I just set the regulator on the gun to read 7-10psi *when the trigger is pulled*, and just disregard what it reads when the trigger *is not pulled*?

[gtcway]

Your method is correct but your pressure settings need to be higher. Use whatever is recommended by Devilbiss for that gun. My GTI Millenium has 29psi stamped on the gun body which will give me 10psi at the aircap, which is what the p-sheet is referring to. You want to set the pressure with the trigger pulled in all the way.

[chrisl]

Thanks! Just to clarify

- as long as the pressure reads 29psi (in your example) with the trigger pulled, I can totally disregard what the gauge reads when the trigger is *not* pulled?
- in your example with the GTI, having 29psi at the gun gives 10psi at the aircap, and this is info *from the manufacturer*, and is not something you can set, and is not something you can really measure at the cap (without something that measures the pressure at the cap?)

I also have a GTI. I think my problem is that my regulator on the gun bleeds a bit if the compressor is more than 60psi. I was thinking that I had it setup wrong, but its more likely just a bad regulator. And its not a Devilbiss regulator, after thinking about it I realized its actually a Sharpe.

thanks

[Len]

Thanks! Just to clarify

- as long as the pressure reads 29psi (in your example) with the trigger pulled, I can totally disregard what the gauge reads when the trigger is *not* pulled?


thanks

That's right, crank up the pressure at the wall so you have plenty of air then plug the hose into the gun and pull the trigger then adjust the inlet regulator to the recommended 29 PSI. It doesn't matter what the gauge reads when you release the trigger. Get a DeVilbiss inlet pressure gauge, it's designed to work properly with that gun.

One more thing... This gun uses a lot of air and you need a decent size compressor to keep up. I wouldn't try to spray an entire car with a compressor that only has a 20 or 30 gallon tank or you could run into problems half way around the car.

DeVilbiss Inlet Pressure Gauge Link

[Dennis N. Schmidt]

If you've got a GTI you need a monster compressor. In liew of said monster compressor you can convert a GTI to a Plus gun (uses 2/3 the air of the GTI) with a simple change out of the nozzle and aircap. These are the only differences between the two guns and because DeVilbiss doesn't screw you over as badly as SATA for parts the entire change cost less than $100. This is what I did to my two Millenium GTI's. I converted them to Pluses. Less air better finish. Gotta love it.

[kenc]

I also have a GTI. I think my problem is that my regulator on the gun bleeds a bit if the compressor is more than 60psi. I was thinking that I had it setup wrong, but its more likely just a bad regulator. And its not a Devilbiss regulator, after thinking about it I realized its actually a Sharpe.

thanks

Well, there's nothing wrong with Sharpe regulators - they're certainly every bit as good as anything else out there, so you don't have poor quality if that's what you're thinking.

[Len]

Well, there's nothing wrong with Sharpe regulators - they're certainly every bit as good as anything else out there, so you don't have poor quality if that's what you're thinking.

You're right, Sharpe makes a decent regulator however they aren't designed to be used on the GTI and the large volume of air needed by the gun may make the gauge and valve in the Sharpe regulator inaccurate. It would depend on the design of the Sharpe regulator as compared to the GTI's air demands it may be fine but it may be too different to be compatable.