Speed Clear

Re runs:
Come on, guys, it is all air at the wall, air at gun, and proper air adjustment.

What if I told you in last week or so I was testing a new batch of UV, shot a coat over an empty black drum.
I had to do inside manuf area because of pollen.
Two of the guys I hired in the last six months were watching, so I handed the gun to the one guy who had been teaching to paint and said your turn and left for 30 minutes.
I came back, and there were five or six drums cleared as he gave another guy who said he held a gun once to look at; he did 1 drum and a second coat on mine.
Slick as glass and not a run on one drum.
All gun adjustment and laying like you want it to look.
I passed the batch and had the other guys come over and see the exemplary job they did.
Maybe it was a bad batch??
 
There is a learning curve to getting it smooth as glass straight out of the gun. When I'm mentoring a Co-worker the first thing I tell them is it takes practice and with that you also have to know the material you are using and how it reacts to the way you spray. Everyone has their own technique and that's all fine and doesn't matter (to an extent) some spray close and fast some farther away and slower etc. Once you get "your" technique down to what makes "you" comfortable you then try to figure what the material needs to do what "you" want end result to be. I always say I would always want to see some smaller peel and have to wetsand and buff that to get it glass smooth then heavy large peel. Heavy large peel can give a slight Thane Wave then smaller peel and makes getting it perfectly smooth difficult to impossible at times.

Always give the booth airline and all airlines in the shop full air pressure to the gun, that is the one thing that I say is a "must not change" rule, what ever your compressor is factory set at "leave it".

Once you get the gun set and your technique down to where you get the small peel in the clear you fine tune your technique in small steps until you creep up on getting the clear to a perfectly smooth finish but that requires doing many projects cause once you got peel you can't erase it with more coats you just compound them.

So I guess the moral of this is to not think and do it backwards. Meaning going from Runs and Thane wave and backing down to a smooth as glass finish, go from working the peel up until you get it smooth as glass.
 
Why does it matter if you adjust pressure at the wall or the gun? Either way, the air is being restricted. The gun regulator would be fully open if the wall was closer to the spraying pressure.

SATA recommends adjusting at the wall.
 
At the wall the psi gauge isnt taking into account the restriction of the hose and fittings. Its always better to have full psi up to the gun and regulate from there
Any idea why SATA says the opposite? I find my jobs turn out better when someone else does them.
 

Here's that SATA video. I hope it is.
Sata recommends a lower wall pressure to minimize the expansion of the hose that runs between the wall regulator and the gun. This gives you less air pressure variation (less initial surge) at the tip of the gun. You do need the wall regulator to be set high enough above tip pressure, however, to allow the gun to maintain it's desired steady-state pressure when the trigger is held full open. That said, I have found that a higher-quality regulator at the gun (like the Sata Adam 2) allows you to get away with higher wall pressures than a cheap regulator.
 
Sata recommends a lower wall pressure to minimize the expansion of the hose that runs between the wall regulator and the gun. This gives you less air pressure variation (less initial surge) at the tip of the gun. You do need the wall regulator to be set high enough above tip pressure, however, to allow the gun to maintain it's desired steady-state pressure when the trigger is held full open. That said, I have found that a higher-quality regulator at the gun (like the Sata Adam 2) allows you to get away with higher wall pressures than a cheap regulator.
This guy, the official trainer, says to make micro adjustments at the gun with the pressure being as close as you can get at the wall allowing for pressure drop to the gun.

I guess it just means there's lots of ways to reach the end goal.
 
This guy, the official trainer, says to make micro adjustments at the gun with the pressure being as close as you can get at the wall allowing for pressure drop to the gun.

I guess it just means there's lots of ways to reach the end goal.
I learned it the way Sata teaches it. Which is why I've had a hard time wrapping my head around the way Barry recommends.i If I set my pressure at the wall and I have the correct pressure at the cap with the trigger pulled according to my digital Sata, how is it different than setting full pressure at the wall regulator and then regulating at the gun? To me it should be less restrictive as the air is only passing through one regulator as opposed to two. Pressure and volume are inverse of one another.
Not arguing, trying to understand.
 
Oops. I certainly didn't mean to say anything counter to what works for Barry. (I need to read more carefully.) One thing I do know is that he knows what works.
 
Really interesting topic.
Motivated me to go read up on how regulators work.

So every time you release the trigger on the gun you can see the pressure gauge go up to the supply pressure, and then drop to the regulated pressure when the trigger is pulled.
There will be a short burst of higher pressure to the tip every time you pull the trigger as the spring and piston/diaphragm in the regulator stabilize to the set pressure. Every trigger pull this happens.
I think tha Sata instructions are trying to minimize this burst by having the wall regulator set very close to the desired pressure, which will be the input to the gun regulator.
They seem to assume plenty of margin in the air compressor CFM and PSI and the loss at ghe wall regulator will not be a problem.

For us DIYers, without industrial compressors, that loss at the wall regulator may take us from acceptable CFM to unacceptable.
The answer for us? Wide open at the wall, set the pressure at the gun.
Pull the trigger "off panel" and then come into it after the fraction of a second of burst is over.

That's what I think. Could be totally wrong though.
 
Really interesting topic.
Motivated me to go read up on how regulators work.

So every time you release the trigger on the gun you can see the pressure gauge go up to the supply pressure, and then drop to the regulated pressure when the trigger is pulled.
There will be a short burst of higher pressure to the tip every time you pull the trigger as the spring and piston/diaphragm in the regulator stabilize to the set pressure. Every trigger pull this happens.
I think tha Sata instructions are trying to minimize this burst by having the wall regulator set very close to the desired pressure, which will be the input to the gun regulator.
They seem to assume plenty of margin in the air compressor CFM and PSI and the loss at ghe wall regulator will not be a problem.

For us DIYers, without industrial compressors, that loss at the wall regulator may take us from acceptable CFM to unacceptable.
The answer for us? Wide open at the wall, set the pressure at the gun.
Pull the trigger "off panel" and then come into it after the fraction of a second of burst is over.

That's what I think. Could be totally wrong though.
But, the question remains: why does it matter where it's restricted? If there's a turbulence created by the restriction, I think I'd want that turbulence to be before the hose. Seems like the turbulence would be flattened out before reaching the gun, eliminating any jolt when the trigger is pulled.

The CFM rises on my compressor as the PSI decreases.
 

But, the question remains: why does it matter where it's restricted? If there's a turbulence created by the restriction, I think I'd want that turbulence to be before the hose. Seems like the turbulence would be flattened out before reaching the gun, eliminating any jolt when the trigger is pulled.

The CFM rises on my compressor as the PSI decreases.
Guys, all air systems, paint guns, painter applications are different, so all I can give
It is what I know will work.

Something I say on the tech line a half a dozen times a week is the only thing that counts is the net result.
If it works, dont change anything.

Edit:
If you have runs, orange peel, a hard time spraying bad metallics, or solvent pop, it might be time to adjust scfm and air pressure.
Twenty-some years ago, a group hired an engineering firm to do one test at the cost of just over $200,000
70lbs at the wall vs. 140.
The results were swept under the table as painters should not know the results thanks to the bean counters.
It's all about the money, your money!
 
Last edited:
My last entry for the regulator topic. I did talk to Devilbiss today and they said adjust at the wall.
 
@Barry
I'll ask this again, cause I'm trying to learn. I don't use a regulator. Haven't for a long time. If I set my wall pressure to such a point that when I pull the trigger on my gun (Sata digital) and I'm getting the "correct" pressure at the cap, then is there any difference if i set the wall pressure as per your recommendations and regulate at the gun to get the same pressure at the cap? If there is I don't understand how. That's what I'm having a hard time understanding.
 
@Barry
I'll ask this again, cause I'm trying to learn. I don't use a regulator. Haven't for a long time. If I set my wall pressure to such a point that when I pull the trigger on my gun (Sata digital) and I'm getting the "correct" pressure at the cap, then is there any difference if i set the wall pressure as per your recommendations and regulate at the gun to get the same pressure at the cap? If there is I don't understand how. That's what I'm having a hard time understanding.
What is your wall set at? How much do you have to adjust on the gun? My wall is around 50 and can only adjust to around 35 at the gun due to pressure drop.
 
It has varied at different places. I like to see 30 at the gun (Digital Sata) before pulling the trigger. 28-32 at the gun is usually what I spray at. I use enough pressure to get the gun atomizing nicely and no more.
 
chris, i think what your doing is right. the digital gun is reading your psi at the gun. set the wall until the gun reads correct and you should be good. for a traditional gun though with no psi reading at the gun i would never set at the wall. you will have too much drop through the hose and fittings. if a gun is rated at 30 psi then 30 at the wall will never give you 30 at the gun.
 
Back
Top