Wet Sanding Pimer - Dots/Pin Pricks Appearing

[lansonm]

Hi All,



I have a question about wet sanding high-build primer.



Everytime I wet sand my primer there are millions of tiny dots / pin pricks that become visible...why is this? Am I doing something wrong? I have tried 600, 800 and 1000 grit sandpaper, it makes no difference. I can sand those pin pricks out, but I get seriously close to going through the primer.



Please help!



Thanks in advance,

Ed

 

[C. Charles Hahn]

What specific primer are you using, and what gun setup are you spraying it with (assuming you're the one applying it as well)?

 

[Ron Ketcham]

Hi All,



I have a question about wet sanding high-build primer.



Everytime I wet sand my primer there are millions of tiny dots / pin pricks that become visible...why is this? Am I doing something wrong? I have tried 600, 800 and 1000 grit sandpaper, it makes no difference. I can sand those pin pricks out, but I get seriously close to going through the primer.



Please help!



Thanks in advance,

Ed

Like Charles says, what gun, etc.

I think it could be a combination of issues.

1. Not enough reducer in primer.

2.Air pressure is too high.

3.Water getting in the air line (this time of year, big concern, I use two water traps.

Those "pits" are voids in the primer due to water, the primer not able to "lay out" or too much air pressure and causing a good portion of the reducer evaporating before it gets on the surface.

That's the easy ones.

However, it's NOT your choice of paper causing the concern.

Grumpy