Reducing PPG Concept Urethane

On Wednesday, January 27, 2016 at 7:44:01 AM UTC-5, wrote:
On Sunday, January 24, 2016 at 12:32:25 PM UTC-5, wrote:

For acrylic urethane I use a turbine HVLP system which gives a big pattern and has no water in the air. I can't make myself use my $400 gun for polyester topcoat so I do get a few fish eyes in that.
FWIW
UH

I know guys that are serious about painting are particular about
what goes through their guns -- never put primer through their
favorite gun and so on. But what's the rationale for this? It
seems to me that the paint follows such a short path through
the gun that it can't cause any serious wear. At least for
gravity feed guns. Are there other issues?

Jim Beckman

The gun I use for AU has a smaller tip than the one I use for thicker filler. This makes it a bit easier to get a better pattern to atomize better which is less of a factor with spray filler. It is also a bit harder to get perfectly clean so I just switch guns. With filler I'm trying to put on a lot of stuff quickly. With finish coats, I'm trying for better finish quality.
UH

The nozzle will elongate over time in the direction of the fan. It is believed that the fillers in primer will erode the nozzle faster. Hold an old nozzle up to the light and this elongantion will show.
I shot gelcoat on this replacement right wing yesterday........heated the paint to about 80f, which helped, but it still needed 10% thinner. Two wet coats gave orange peal to the max. Shot a 'leveling' coat with an additional ounce of thinner and fan opened up with gun a foot above the work........it looks pretty good. Must have 30 pin holes in places I inspected with a light and even a magnifying glass..............where (how) do they form? Catalyzed a tad of paint and filled the pin-holes with a tiny brush. The bump will disappear with wet sanding.......hopefully with 800 wet and then buff out after curing for about a week.
I hate painting, but it is the final thing that must be done after a repair!
;) JJ

Try 3M dry guide coat for sanding. It is a miracle product.

Lane

I mix. 4 Ppg
3 1/2 Reducer
1 Hardner
1 cap. Fish eye remover


Can usually start sanding with 1000 grit