Large amount of dust in new paint :(

[Charles]

This afternoon I painted the car with acrylic urethane and the 1.3 tip in my new GFG-670 Plus gun. The difference between the Plus and the HF Cheapo is amazing... no runs and the paint went on nice and smooth. Also, one gallon was the right amount to paint the entire body (including engine bay, stripped interior, and trunk) also. No more cheap guns for me!

Unfortunately I have a dusty, dirty garage and apparently didn't clean the car enough either, since there are large numbers of dust nibs They are most numerous, or maybe just most obvious, on the roof.

I should have read some of the dust threads first - I'm learning belatedly everything that can go wrong!

So can I sand out the dust with a fine grit? Will I need to apply some more color after? I hadn't planned on spraying a clear coat, but will that now be required after color-sanding?

[Len]

This afternoon I painted the car with acrylic urethane and the 1.3 tip in my new GFG-670 Plus gun. The difference between the Plus and the HF Cheapo is amazing... no runs and the paint went on nice and smooth. Also, one gallon was the right amount to paint the entire body (including engine bay, stripped interior, and trunk) also. No more cheap guns for me!

Unfortunately I have a dusty, dirty garage and apparently didn't clean the car enough either, since there are large numbers of dust nibs They are most numerous, or maybe just most obvious, on the roof.

I should have read some of the dust threads first - I'm learning belatedly everything that can go wrong!

So can I sand out the dust with a fine grit? Will I need to apply some more color after? I hadn't planned on spraying a clear coat, but will that now be required after color-sanding?

Yes, there are a million variables to the painting process and eliminating dust probably has a few dozen major variables. I'd recommend that you use a Nib File to chop off most of each dust nib then sand the surface with some 1500 wet sandpaper then buff the surface to see what it looks like before making any further decisions. If it looks ok then you know the process but if it's a bad looking job then you may need to do more prepping and painting.

Nib File Link

[Charles]

Thanks. Your link takes me to the coarse nib file. Should I also order a fine one? I've never used one so don't know how aggressive they are...

[Len]

Thanks. Your link takes me to the coarse nib file. Should I also order a fine one? I've never used one so don't know how aggressive they are...

Yes, sorry about that, the coarse one is better for runs but the fine one is better for dust nibs.

[frostje]

Dust and dirt are the enemy. That is just , IMO , the biggest problem is a good CLEAN job. Not easy. Advice is keep air movement to minimum. Wear paint suit. Make sure your exhaust is not blowing anything around. Clean, tack, clean again. Wet the floor. Dust really is the biggest problem for any person without a booth or a homemade booth. Just not easy to get dust free

[Charles]

I had a good look at the Dart today in bright sunlight and it has way too much dust to remove each nib with a file... there's one on just about every square inch and it would take forever. Also a large pile of mouse turds fell out of the trunk lid after I left, and stuck in the paint on the rear deck (no tiny footprints so the turds must have been inside the lid somewhere... sigh.

The engine compartment, interior and trunk are just "OK" but since it will all be mostly covered up with a big-block with headers, seats, and fuel cell/battery box/nitrous bottle respectively, I have started on the mechanical stuff in those areas.

So I'll leave all the trim/bumpers/glass off, and probably hand sand the whole car AGAIN. Would 400 grit be appropriate?

I am discouraged and seriously considering taking it to a body shop for the final coat. I am stubborn though and may try just one more time with a homemade paint booth (2x2's and plastic sheet, furnace filters, box fan) and a Tyvek suit...

[Len]

I had a good look at the Dart today in bright sunlight and it has way too much dust to remove each nib with a file... there's one on just about every square inch and it would take forever. Also a large pile of mouse turds fell out of the trunk lid after I left, and stuck in the paint on the rear deck (no tiny footprints so the turds must have been inside the lid somewhere... sigh.

The engine compartment, interior and trunk are just "OK" but since it will all be mostly covered up with a big-block with headers, seats, and fuel cell/battery box/nitrous bottle respectively, I have started on the mechanical stuff in those areas.

So I'll leave all the trim/bumpers/glass off, and probably hand sand the whole car AGAIN. Would 400 grit be appropriate?

I am discouraged and seriously considering taking it to a body shop for the final coat. I am stubborn though and may try just one more time with a homemade paint booth (2x2's and plastic sheet, furnace filters, box fan) and a Tyvek suit...

When spraying almost all dust comes from the car with minor amounts that may come from the surroundings. So, unless you generate more dust you probably won't get nearly as much the second time that you spray. Clean the surface by using low pressure air to blow out all cracks, crevasses and wipe the surface while blowing across it then wipe with a damp sponge and rinse the sponge in a bucket of clean water and dry the surface with a clean towel then use a tack cloth to wipe the surface right before you spray.

[junk]

That does sound like a lot of dust. I've painted in some pretty bad/dusty garages and never had that much trouble. I say this to basically I would completely agree with Len on where the dust comes from. I think you can do it. Sand the vehicle blow it off with compressed air. make sure to blow out every knook and crany. It's amazing how many areas the spraygun hits with air you wouldn't think it would. I'm a nut about blowing off and out each panel after each sanding round. It makes the surrounding area a dusty mess, but keeps the car cleaner.

Maybe even do a dry run painting the car with the gun and just air and watch for areas the dust is coming from. Probably be surprising. Also watch what your touching when your painting. I was painting the roof of a pickup so i was on a ladder. When I was getting off the ladder I lost my balance and touched the rafter knocking down wood chips into my clear coat!