Help please

[F100kid]

I haven't posted since Aug, but I have a real problem! I sprayed my truck with Paint Shop blue and the it came out very grainy. I've been painting since the '60s and have never seen this before. I used Dupli-Color primer, Dupli-Color base, but acrylic laquer clear. I'm pretty sure I read on here somewhere that they were compatible and the base was already grainy looking. I figured that spraying my clear may cause it to flow out, but no such luck.

I had 55 lbs at the nozzle, and the gun was loaded thru a filter. The temp was in the 90s and the bloody humidity was, too (long sleeves used). I don't think that was my problem as I've done it before.
After letting the clear dry sufficiently(several days) I started color sanding with 1200 grit, but dropped back to 600 and finally 500 grit to no avail. I even started compounding, but the paint is still grainy. I won't blame the equipment as I sprayed a front fender with the same equipment, but a competitor's brand paint and it came out great.
I'm not looking for sympathy or freebies, but I AM looking for answers and suggestions.
HELP!

[Dupli-Color-Specialist]

I haven't posted since Aug, but I have a real problem! I sprayed my truck with Paint Shop blue and the it came out very grainy. I've been painting since the '60s and have never seen this before. I used Dupli-Color primer, Dupli-Color base, but acrylic laquer clear. I'm pretty sure I read on here somewhere that they were compatible and the base was already grainy looking. I figured that spraying my clear may cause it to flow out, but no such luck.

I had 55 lbs at the nozzle, and the gun was loaded thru a filter. The temp was in the 90s and the bloody humidity was, too (long sleeves used). I don't think that was my problem as I've done it before.
After letting the clear dry sufficiently(several days) I started color sanding with 1200 grit, but dropped back to 600 and finally 500 grit to no avail. I even started compounding, but the paint is still grainy. I won't blame the equipment as I sprayed a front fender with the same equipment, but a competitor's brand paint and it came out great.
I'm not looking for sympathy or freebies, but I AM looking for answers and suggestions.
HELP!

What style gun and tip size are you using? 55lbs at the nozzle is probably where your problem is. That is higher than you need to spray Paint Shop. Also the temp and humidity is also the issue. Paint Shop is lacquer paint therefore dries very quickly and could get grainy with high temps. Wetsand your paint back down so it is smooth. Recoat when temps and humidity come down to the 70-80 range. When applying the clear you are going to want to slow that way down. By this I mean moving the gun slower on each ass and hold it closer. This will help the clear flow and let it level out more. Always lay down the first coat of clear light and then heavier there after.

I hope this helps you out.

[F100kid]

I take blame for saying I used 50 psi at the nozzle, when in fact I used 40 pounds.
As far as the gun itself, it is gravity feed, but not HVLP.
The nozzle size is 1.4 mm.
Humidity's effect on acrylic lacquer only makes the paint milky, which will buff out. I found that out by painting motor cycles in my basement. I'm not sure what it does to Dupli-Color. I'm just not convinced humidity could cause paint to literally look like and feel like sandpaper .
As they say, back to square one.

[Dupli-Color-Specialist]

I take blame for saying I used 50 psi at the nozzle, when in fact I used 40 pounds.
As far as the gun itself, it is gravity feed, but not HVLP.
The nozzle size is 1.4 mm.
Humidity's effect on acrylic lacquer only makes the paint milky, which will buff out. I found that out by painting motor cycles in my basement. I'm not sure what it does to Dupli-Color. I'm just not convinced humidity could cause paint to literally look like and feel like sandpaper .
As they say, back to square one.

F100, Thanks again for the feedback. Try thinning down the paint a little with lacquer thinner and try it again. Also try backing down the air pressure to 25psi. I am personally not familiar with a NON HVLP gun so I could be wrong here. It doesn't take much pressure to spray Paint Shop from a gravity fed gun. Too much pressure could force dry it which would cause a grainy result especially with Metallics.