I need some guidance please?

[Bjorn.LaSanche]

I’m at the tail end of my clear coating. I probably have enough lacquer for maybe 4 more coats. I know when shooting metallics you bury the particles in your tone and clear coats. The thing is I am seeming to be growing particles.   The photo is the best I was able to take as they are hard to see unless right there.  It’s the little sharp points in the photo. It isn’t dust caught in the lacquer as I wipe wipe a tack cloth before each coat. If you look at them one direction they look like bad acne, look from a different direction they’re gone.   
 

ive read many threads online of people lightly sanding to knock stuff like this down before the final wet coats. Thing is, is this a wet or dry sand and what grit sand paper, and would you even suggest it?  I just don’t want to run out of lacquer and someone say you should have sanded those flat before your final coats type deal. First photo is what I’m talking about. Next photo just showing off

[Bizman62]

11 hours ago, Bjorn.LaSanche said:

ive read many threads online of people lightly sanding to knock stuff like this down before the final wet coats. Thing is, is this a wet or dry sand and what grit sand paper, and would you even suggest it?

To me that looks like you've sprayed a little too far away, which has enabled the lacquer droplets to partially dry before hitting the surface. Spraying is a dark art, the unholy trinity of temperature, thinner and distance. A change in one requires some testing to get the other two right. Humidity, ventilation and air pressure add complexity to the formula...

• If it's cold, the lacquer is stiff so you need to add thinner for an even flow and a short enough drying time to prevent runs, and then find the right distance to keep the lacquer liquid until it hits the surface
• If it's hot, the lacquer is more liquid and will dry faster so less thinner is needed. Again you'll have to find the optimal distance.
• If the shooting pressure is low, the droplets run slower allowing them to dry during the travel. Again, test.

Regarding sanding, I've always sanded lacquer wet since it both seems to be smoother and keep the dust out of my lungs. Use a block on flat surfaces and be extra careful not to sand through the edges. Use no pressure at all, the weight of the block is plenty enough, also flush the paper and wipe the slurry often. My choice to start with might be 600 grit, 400 might be too aggressive and 800 too slow which could make you use too much force, causing the abrasive slurry lumps make deep scratches. Your aim is just to knock the tops off of those micro lumps. If you manage to level the surface to a satin matte you're golden.

[Bjorn.LaSanche]

Thanks for the tips and yes, you’re right. The lacquer was starting to dry before it hit the surface.  I’m still somewhat dialing in the gun.  I’ve increased the air pressure about 10 psi at the gun and reduced the spread some so it is rounder now. It’s allowing me to lay down a wet pass now.  It was one of those Aha moments. I’m used to spraying with a standard HVLP turbine system when I was doing apartment maintenance for a living. Using a compressor and hvlp gun is a little different as it has more controls to it. I also wasn’t shooting lacquer  

 

thank you for the tips regarding the temperature.  I’ve already run into having to deal with blushing as the final coat I applied Friday night blushed bad. Luckily the Mohawk distributor is open Saturdays and is five minutes from my house. I picked a can of their No Blush with Retarder and sprayed a light coat over the areas and then pushing was gone in five minutes. 
 

Have to say I am hooked on this line of product. I have had no difficulties with it at all.  The vinyl sanding sealer is inexpensive and way easy to work with, the metallic base is comparable to auto metallic base that runs $125/qt., the lacquer is really clean and almost doesn’t need strained. Woodcraft sells the lacquer normally for $23/qt. The distributor can get me gallons at $36 per but I have to buy a case at a time(4). Otherwise it’s $50/gal. The last item I need to try is the aerosol lacquer which I’ll need as I still have to finishing to do on the headstock face.  
 

ha I’m already itch to start my next build. Same model, different wood and will not make the errors I did last time. 
 

again, thank you Bizman62 and I did t mention it above but I wet sanded with 600 to knock down the main sharp points showing through. And once I wasn’t getting resistance moving the sand paper with 600 I cleaned the guitar off and ran another sanding session using 800. I always use a block except for edges. For those I fold the paper enough so it acts as it’s own block on a shape like this I’ll origami the paper into a 1” x 4”rectangle I bend in half and run it single direction applying only enough pressure at any time with finishes to move the paper.  That goes for dry sanding too.  Learned a long time ago sandpaper is designed to cut using only enough pressure to keep the paper on the surface and moving.  It works against the paper to apply pressure more Than that. 

Edited August 8, 2021 by Bjorn.LaSanche
Added info

[Bjorn.LaSanche]

upon reflection, I was getting the spray pattern control and liquid amount control backwards.  This resulted in exactly your thought of paint going on too dry.  I bring this up as I did it again the other day testing a different media.  I think I'm going to have to put a piece of tape with a note on the cup for a while.  Using a hvlp gun sure beats rattle cans any day.  If nothing else but straight up comfort.  I have to wait another week or two for final sand and buffing as I tried last week, but I would get to a certain point and I could feel the finish move in a few areas under the sandpaper.  I stopped and doesn't appear to have done anything horrible.  I ll just focus on other aspects of the build I still need to finalize.  I have to remake the pick guard as It is too narrow in the control area.

[Bizman62]

Thanks for telling! It's one thing to ponder logical options and another thing to hear that an educated guess really nailed it.