Adjusting air on a Astro EVO LPLV gun

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PostPosted: Mon May 05, 2008 8:32 pm
Glad to see you got it sorted out.

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PostPosted: Mon May 05, 2008 8:42 pm
Ryan S. wrote:Working now!I screwed it in open all the way and BINGO, plenty of AIR. can set it where ever I want now. ~48psi at the gun gives me ~25 with trigger pulled.
So my understanding is you screwed the valve that is on the compressor all the way in is that correct?

Thanks for posting your outcome so we all know what to look for if we run into the same problems.



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PostPosted: Mon May 05, 2008 8:52 pm
My compressor pumps up to 120psi max, cuts back on at 90psi. I had just turned it open more until I was at the 120psi or so, which was max for me anyways so never thought about it again. Apparently there is still a big restriction then when whatever valve or control that is there is still in the way restricting flow, and that was the problem!

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PostPosted: Tue May 06, 2008 1:36 am
Something is still not right. That is way too much of a pressure drop.... Glad its working better for you, but I assure you, your life will be so much easier when you get your setup dialed in. Please post pictures! ;)



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PostPosted: Tue May 06, 2008 8:26 am
vwbobby wrote:Something is still not right. That is way too much of a pressure drop.... Glad its working better for you, but I assure you, your life will be so much easier when you get your setup dialed in. Please post pictures! ;)


So in your case in previous post (you said 5-10psi drop) are you saying if you set a regulator on the gun to 30psi you get 20-25psi with the trigger pulled? As long as I have what I need with trigger pulled I am probably good to go though?

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PostPosted: Tue May 06, 2008 8:36 am
I may be all wet here but I still think you need to be certain your compressor is putting out enough volume of air (CFM) at 40 psi to handle your guns.
The Astro LVLP units do not use much air but they still require nearly 10 CFM to operate correctly. (see link below) Yes, you can "get by" with less air if you have to but the gun will not perform as well as it could.
http://www.spraygunworld.com/products/A ... VO4014.htm

Compressor ratings are all over map with some deliberately overrating their compressor's output levels just to get sales. I started with a smaller compressor and although I could get a DA sander to run (barely) and my paint gun would "spray" material none of these items were working correctly. When I got my new compressor there was a very noticeable difference in how my tools operated.
1968 Coronet R/T


ACTS 16:31

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PostPosted: Tue May 06, 2008 9:23 am
'68 Coronet R/T hit the nail on the head! Just because it will "work" doesn't mean you'll get good results without having to fight with your equipment.

Yes, there should only be a 5-10 PSI pressure drop max. I get around 3-5psi drop at the gun. My regulator is directly attached to the bottom of my gun and the bubble filter is on the inlet side(of the regulator), the hose fitting directly into the filter. I basically filter my air before it hits my regulator, and there's less chance of the filter snapping off from weight/stress.

When you have a big pressure drop, you can get a really big surge/blast of pressure (in your case, 48 or so PSI) for a split second until the pressure runs down. It can cause 2 problems..... Sudden burst of material at the instant the trigger is pulled OR (more common) higher pressure blast of air then the material starts to flow and the gun goes down to its ~20-25PSI. Either way, its not smooth consistent air/material.

My compressor is putting out 12 CFM at 90PSI, 60 gallon - its BARELY enough to run a DA and it starts working the pump too hard after a minute of continuous use.

Sorry, but those commercials that Sears, Home Depot, etc put out showing someone shooting paint in their garage with a 21 gallon compressor is just for show. Spot repairs/panels, OK.....completes....No way! I really just want to see you get this dialed in...I hate seeing things "broken". If you have one of those dreaded "curlie cue" air hoses, get rid of it now!



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PostPosted: Tue May 06, 2008 10:25 am
I'm certainly on the small, barely getting by side on the compressor, I knew I was going to have to be carefull with that from the start. Epoxy, 2k, Base went on fine and that with my tank regulator holding back airflow big time. Manufactor recommended more air for the clear and I think I found the problem on that. Compressor is a $99 3HP 21Gal Harbor Freght unit ( :roll: I know). Sometimes I dip to around 75psi in the tank, runs the entire time while spraying. Just try to work slow and divided up how I spray to give as much pause time for compressor to keep up while I stop for a door jab, etc, while trying to pay attention to keeping wet edges. Have to figure it out before my gallon of clear runs out, but I think I'm getting it down. I probably do some minor touchups, color sand and buff where I'm already at and have a pretty decent job.

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PostPosted: Tue May 06, 2008 2:32 pm
Ryan,
The volume of the air (Cubic Feet per Minute) is what is critical not the PSI. You can pressurize a small amount of air to 125 psi but once you open the valve that small amount of air escapes so quickly that what little volume (quantity) of air you had is gone.
Your compressor should state on it somewhere what the CFM output is at say 40 psi.
1968 Coronet R/T


ACTS 16:31



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PostPosted: Tue May 06, 2008 3:04 pm
Compressor is a $99 3HP 21Gal Harbor Freght unit


I told you in the very beginning it was your compressor. You just can't spray with that compressor .

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