Fine Sand Grit In Paint Job

[ZeMadMonkey]

I am putting this question out to anyone who can shed some light on this issue I am having, possibly other painters who live in hot and dry environments. I live in Phoenix, AZ.

I have been trying to paint this summer but keep getting what looks like tiny granules of sand in my paint job, it appears to be dried paint. It is not one or two pieces, which I might attribute to dirt, though I have never had a problem with dirt before. It is throughout the coat. It even occurs with primer when I am using the 1.8 tip, which is ridiculous.

This happens whether I am using AutoAir waterborne paint or House Of Kolor paint. It happens whether I am using my Devilbiss or Sata gun.
I am painting in my folks’ garage, open air, with a 60 gallon air compressor. I have a dedicated moisture separator, an air regulator with it's own moisture separator, an inline filter, and of course the filter in the paint cup. I meticulously clean my guns after each use, break them down and clean them. I also have two fans to keep air flow through the garage; one at the front of the garage, and one at the end of it. Just last month we completely scrubbed and cleaned the garage from top to bottom.

My only guess, as to the cause of this grit in my paint job, is that it is so hot when I am trying to paint that the paint is drying in my gun while I am laying down the paint.

Thank you for reading my post and any suggestions for fixing this.

 

[Wydir]

are you using a tack rag between coats? if not you should be , Also make sure you are using the right reducer,
could be to far away from panel, these are just thoughts

 

[ZeMadMonkey]

Thank you for the reply Wydir.

I am not using a tack rag between coats. Does that just clean you surface before you next coat?

I am within 6 inches from the panel and using the correct reducer at 10% reduction.

 

[Wydir]

what paint are you using?

 

[ZeMadMonkey]

I am using House Of Kolor for primer and clear, but Auto Air for all the color

 

[Wydir]

well the only thing in common with all your problems is the air supply, You may need new filters , new air hose, maybe oil from compressor any number of things.

 

[TAZ]

You didn't mention if the problem was when you spray the base or the clear of House of Kolor, but I am assuming it's the base.
Isn't the reduction 2 to 1 or 1 to 1 (not 10%). That would be some pretty thick paint to spray.

 

[ZeMadMonkey]

Thanks for the reply TAZ

The grit is occurring in the primer and the colors, I don't even move on to the clear coat as the paint job is ruined already, don't want to waste time clearing. Below are the ratios of material to reducer I use at the various stages in the paint job.

HOK Primer - 10% reducer
AutoAir Colors - 10% reducer
HOK Clear - 2:1:1
HOK Flo Coat - 2:1:1 1/2

 

[Wydir]

well the grit in the primer should not matter to much as your going to sand it smooth anyway, After you are done sanding do you blow off the piece and surronding area? I would also get some tack rags to wipe the dust off between coats. the primer should be sanded with 600grit and cleaned prior to topcoating with the auto air colors.

 

[ZeMadMonkey]

Definitely Wydir, I always wetsand my primer with 600 grit sand paper before top coating with Auto Air. I drycoat with 3M applicator and wetsand my primer before topcoating.

The problem is the same grit appears throughout my AutoAir layers, which I can not sand. I just mentioned that is occurs in the primer stage as well, just so everyone knows it not outside dirt. The it is occurring with both regular paint and waterbased paint. It is something going on with my paint application, since it is throughout the coat.

I appreciate all your responses to my issue

 

[Wydir]

im still going to guess its in your air supply, maybe the best thing to do is mix up like 4oz of clear and spray a test piece and see what comes out.

 

[TAZ]

I agree with Wydir. It can't be the primer since this is sanded smoother before you base. I don't know too much about Auto Air, but 10% is very little reducer. I'm more familiar with HOK and PPG basecoats which is reduced quite a bit more than the 10%

 

[scapegoat]

Sounds like the paint is drying in the air before it reaches the surface . You may need to use the correct reducer , hold the gun closer , and slow down your travel speed . If the dirt looks like tiny pieces of broken glass ( very sharp edges ) you have a dirty spray gun . Also how old is your air hose . The inside could be coming apart and ending up in your paint .

 

[ZeMadMonkey]

Thanks scapegoat

I think I am going to have to check my air hoses. These are the same air hoses I have had for years. I didn't know they could break down.

Thank you everyone for your suggestions on how to resolve my issue, any one have more ideas keep them coming.

 

[scapegoat]

All the comments are very good . Keep us posted and let us know what you found out .

 

[devinraycooper]

Did you ever figure this out? Try slowing down your travel speed like scapegoat said. You could have the right distance and reducer but move too fast and spray everything on "dry".