Ok I might get to spray again today.

Is there a better way to set your gun?

I put paint in and spray a lot of liquid gold on a test board before I think I have it set right only to start spraying the parts and find it is spitting  spots instead of a mist.

Or you need to clean your gun.

When was the last time you had it completely disassembled for cleaning?  Did you buy it new or used?

Is it always spraying droplets? (If so, Robert's guess is probably right, or you have a clogged passage).  Is it an old-style or an LPHV gun?  (If it's LPHV, I don't know much about it).  Is it going "phut phut", sometimes spraying droplets and sometimes spraying a nice fine mist?

Most important -- what pressure are you running?  I run 30-40 pounds to my touch-up gun, which is less than I wanted to but all that my half-broken-from-the-store Horror Fright "regulator" can manage.

Or the material is too thick. Generally, if the material is coming out in splats, it's either not enough pressure or the material needs to be thinned more. Or both.

It could be one of the reasons listed by Sparky or Randy. Another thing to think about is filtering the paint. I use TWO paint filters (the ones you get at the auto paint store) when filling my gun.

Derek

Jim, are you saying 20 foot of hose is too long? what is the correct length to get the correct pressure?
Thanks,

-Dan

I use a top feed HVLP gun from Harbor Freight.  I have two, one for clear and one for color.  They are older and work well.  I ran into this very problem the first time I used them. 

Solution, more pressure.  I set the line pressure at about 90 psi.  I have a small in-line regulator at the inlet of the gun.  I set that to the desired 7-10 psi range depending on the material I am spraying.  I have had no spitting issues since, when the gun is clean and in good working order, fingers are crossed and knocking on all kinds of wood now.  Also on my model there is a small pressure adjustment screw on the bottom of the gun but there is no gauge so its hard to use.  With the inlet gauge I can see the pressure settings and I leave the one on the gun base wide open. 

An inline gauge at the base of the gune is a must.  It just makes things that much easier.  Plus they are pretty cheap. With the line pressure way up you will never get pressure buildup or drop off in the gun no matter what the compressor is doing.  I use a 20' hose as well.

Well if the rain will ever go away i might get to spray some clear.

Not an expert on this like some, but I think the dope gloss comes after it cures and is rubbed out.   The automotive clears seem to cure with a gloss after the second coat.   I usually hit with a light coat and then with a heavier coat on second application.

Hi Fred,

From your pictures it appears you have a case of blushing.  It occurs, as you probably know, from high humidity.  We have the problem here most of the year.

BIG Bear
RNMM/AMM

I did some research on line which says you can eliminate blushing by spraying 100% thinner over the blush on a low humidity day. Has anyone tried that?

Also, can you simply wet sand and polish the blushed dope to a glossy finish?


Its still soupy out here in CT, so I have to wait....

Paul, if you have a non-HVLP gun then put some oil around the packing nut on the shaft.  These packings dry out out after a lacquer or other thinner type wash.  Air is then sucked in causing the eratic flow.

I was surprised at how my pressure I had to use with my nominally HVLP gun. I dial up the compressor to max (about 120lbs) and use the regulator at the gun to dial in the amount of pressure needed. With the Finex gun I use from color, it ends up being between 30-40lbs though the gun says no more than 10lbs. But it works well there (and yes, I know you check the pressure with the trigger depressed). I set it at around 35lbs and it drops to about 15lbs when used. This seems to work pretty well. I use more than that with the SATA clear gun. But I'm usually shooting catalyzed polyurethane and that is a somewhat different deal.