HarleyTechTalk

Looking for info on any better regulators that hold the set pressure at low pressures, like 20 PSI. I pre regulate down to 80 PSI but I need to hold the pressure steady at the bottom of my paint gun. The cheapie ones drop a lot when I spray so I end up having to set the pressure while spraying. And I'm not convinced how good they are even then. 

Have you checked out Wilkerson High Precision Regulators?

you need two on your compressor , one for main pressure , and other down line to regulate , any body and paint shop has them, never had any problems with them ,some have the bowl under neath, cheers

Quote from: Coyote on November 14, 2013, 04:31:13 PM
I pre regulate down to 80 PSI but I need to hold the pressure steady at the bottom of my paint gun.

I am using two.

http://www.automationdirect.com/adc/Overview/Catalog/Pneumatic_Components/Pneumatic_Air_Preparation_(FRL-Filters,_Regulators,_Lubricators)?gclid=CPudmpXQ5boCFQxgMgodnRwAkA

They have some with a 4-57lb range that might work for you.

They all drop press. between lock up and full flow. Just set it where you want it when spraying and don't worry about press when not spraying.

Quote from: greasy on November 14, 2013, 05:24:51 PM
They all drop press. between lock up and full flow. Just set it where you want it when spraying and don't worry about press when not spraying.

That's what I have been doing. Just wondered if there was something better. I just ordered a new gauge today that's 0-30 PSI as the one on my gun regulator now is 0-200 PSI and very doubtful it's accurate at 20 PSI.

A regulator will work best in its middle of range has apposed to bottom of range and needs adequate flow to it to keep the steadiest pressure.  Maybe your second regulator needs a different range.  Bob

Quote from: FXDBI on November 14, 2013, 07:28:42 PM
A regulator will work best in its middle of range has apposed to bottom of range and needs adequate flow to it to keep the steadiest pressure.  Maybe your second regulator needs a different range.  Bob

No doubt which was why I was looking. The regulator/gauge I had was 0-200 psi. I need 20. I found a 30 psi gauge but no luck on the regulator.

I think most painters use a simple valve along with a small gauge right at the gun for easy final adjustments to pressure change.  I don't remember painters using anything much different than the Sharp regulator/filters I sold but that has been a while.  I have a friend that has owned a large body shop for decades if you would like me to inquire.   Rick

One thing you can do is add a large pressure vessel between the second regulator and the spray gun.. This will act as a compensator to keep the pressure drop low and more constant.  Size up the feed hose from the vessel to the gun to eliminate pressure drop in the hose on start of spray..  You could just try a larger hose between the regulator and the gun.. Remove any restrictions like quick connects..

Is the second regulator mounted on the gun? That might help but the vessel might work better.. Depends on the response time of the regulator.

Max

yep

Just get the proper gauge then bleed the pressure at the gun, which you should be doing anyway before material comes out.

Quote from: Max Headflow on November 14, 2013, 08:53:38 PM
One thing you can do is add a large pressure vessel between the second regulator and the spray gun.. This will act as a compensator to keep the pressure drop low and more constant. 

An accumulator of some type should be the fix.

Quote from: autoworker on November 15, 2013, 05:41:36 AM

Quote from: Max Headflow on November 14, 2013, 08:53:38 PM
One thing you can do is add a large pressure vessel between the second regulator and the spray gun.. This will act as a compensator to keep the pressure drop low and more constant. 

An accumulator of some type should be the fix.

There is already an accumulator in the system, the compressor tank. The problem isn't a pressure drop is a pressure build. The air hose is flexible and the air pressure builds and it expands. To test it just hook up your gun to the hose and listen to the sound of the air coming out of the tip. The initial high pitched burst is the build up of air then it will settle down the pressure you have set thr regulator on the gun to.

Brings back my days as an autobody mechanic and painter. Sprayed a few aircraft too. The most important thing is to have correct pressure at the gun. Unfortunately there's a hose between the tank regulator and the gun. Tank and gun pressure will be different. Only real solution is to pre trigger the gun (air) and drop the surge, or run the regulator as close to the gun as possible. One example would be a clip on the belt arrangement. Then you only have a short hose from the reg to gun.
Ron

Quote from: rbabos on November 15, 2013, 06:14:02 AM
Brings back my days as an autobody mechanic and painter. Sprayed a few aircraft too. The most important thing is to have correct pressure at the gun. Unfortunately there's a hose between the tank regulator and the gun. Tank and gun pressure will be different. Only real solution is to pre trigger the gun (air) and drop the surge, or run the regulator as close to the gun as possible. One example would be a clip on the belt arrangement. Then you only have a short hose from the reg to gun.
Ron

Modern guns have regulators built in or you add one at the handle.

Just to be clear.  Are you using something like this at the gun?  If so, these are not true regulators, more so a "flow restrictor".

[attachment removed after 60 days by system]

Quote from: 06roadglide on November 15, 2013, 06:19:12 AM
Just to be clear.  Are you using something like this at the gun?  If so, these are not true regulators, more so a "flow restrictor".

True. I've found them no better then a plain old valve.
Ron

Quote from: frankieb on November 15, 2013, 06:03:10 AM

Quote from: autoworker on November 15, 2013, 05:41:36 AM

Quote from: Max Headflow on November 14, 2013, 08:53:38 PM
One thing you can do is add a large pressure vessel between the second regulator and the spray gun.. This will act as a compensator to keep the pressure drop low and more constant. 

An accumulator of some type should be the fix.

There is already an accumulator in the system, the compressor tank. The problem isn't a pressure drop is a pressure build. The air hose is flexible and the air pressure builds and it expands. To test it just hook up your gun to the hose and listen to the sound of the air coming out of the tip. The initial high pitched burst is the build up of air then it will settle down the pressure you have set thr regulator on the gun to.

The issue is that the accumulator is on the wrong side of the regulator..   The hose issue you are talking about is more then likely the size of the hose and any other restrictions causing a pressure drop because the is not enough flow.. Measure the static pressure in a hose with no flow and it will be the same throughout the hose.. Once the valve at the gun opens pressure drops at the gun until the pressure drop travels back up the hose to the regulator.. Also all regulators need a bit of feedback to work.. It's a simple control loop... A regulator that has a higher flow rating and a larger diaphragm might work better as the feedback gain is typically higher..  I would think that mounting a pressure gauge at the gun should be able to verify this..

Rons suggestions should work as moving the regulator closer to the gun decreases the length of the hose.  Also pre trigger works..

I know very little about the different spray guns but I'd also check the gun to make sure it doesn't have an issue on flow start.

Max

My current regulator is screwed into the base of the gun itself. It's a regulator, not just a valve. I'll change out the gauge next week and see if that helps. Running a 200 PSI gauge it's very difficult to tell where I'm really set.

Setting the pressure with the gun full open is standard procedure.

Quote from: Coyote on November 15, 2013, 07:06:04 AM
My current regulator is screwed into the base of the gun itself. It's a regulator, not just a valve. I'll change out the gauge next week and see if that helps. Running a 200 PSI gauge it's very difficult to tell where I'm really set.

Should be ok then. Good lower reading gauge and set pressure with trigger pulled should get you there.
Ron