What Should a Mist Coat Look Like?

Another helpful hint: You are using Gunze H series acrylic paint. They love 90% ISO, don't use water or any flow retarder. You can also use their MR. Hobby thinner with the blue label. It has a citris/alcohol smell to it, similar to Tamiya X-20A.

Hard to believe that my Fine tip was dead on arrival. I just replaced it with another 'new' one and it works like a charm now. I was very unsuspicious of it. Thank you very much everybody trying to help me here.

Phil h is absolutely right. Lacquer thinner will allow the fines spray possible allowing super slow and smooth buildup. Use low air pressure - psi.

Personally, I wouldn't use water as a thinner, even though the Gunze label says you can.

Water will increase the surface tension causing (1) lesser atomisation of the paint, which results in larger droplets in the spray pattern, and (2) a tendency for the paint on the surface to bead and "pull" into pools, which may be exacerbated by surface contamination from handling.

If you want really super-thin "glaze" coats, thin with Tamiya lacquer thinner or Mr Color (lacquer) thinner, either of which will allow you to thin >75% thinner easily.

fermis has a good idea too.

Acrylics by nature do dry quick, and though you have added retardner, the water likely negates a lot of that. 

regards,

Jack

Another thought...rather than thinning so much, you could mix the paint with clear flat (if it's the same sort..ei, acrylic...I'm assuming you're using acrylic paint???). This allows you to spray at a normal "thin-ness". May be worth a shot on a testbed. I have zero experience with acrylics, so I can't promise anything! I do mix enamel paint with clear flat lacquer all the time. Mainly, I pretty much just "tint" the clear to spray over decals to tone em down/weather em a bit. I works great, and the results are better than trying to do the same thing with very thin paint(which give me the tiny dots you describe).

It depends a lot on the two colours - at extremes such as going white on black, then yes you could very well see dots.   You might have to introduce the original base colour into the airbrush mix to alleviate that problem.  Also, use a wide coverage spray - but I have a feeling maybe the water is causing the droplets to form. 

Might help to post a pic of what you are ending up with.

regards,

Jack

jgeratic

Mist coat, you should still see the underlying colour.   You are correct to thin the paint so you can slowly build up the paint layer.

Assuming all the ingredients are compatable and not separating your paint in the airbrush, I'd suggest to practice on a scrap surface, even paper will do.  Other things to try is decrease the psi,  remove the needle protection crown to avoid build up of paint inside - that can spit out in clumps.  Make sure the needle point isn't damaged, as that too can cause spitting.  Also be certain the moisture trap is working, and no water is entering the airbrush proper.

regards,

Jack

 

Thanks for the reply. Am I supposed to be able to see hundreds of very little spots with a light coat? Because it is what I get, a translucent coat with hundreds of dots. (does not look like spitting)

Mist coat, you should still see the underlying colour.   You are correct to thin the paint so you can slowly build up the paint layer.

Assuming all the ingredients are compatable and not separating your paint in the airbrush, I'd suggest to practice on a scrap surface, even paper will do.  Other things to try is decrease the psi,  remove the needle protection crown to avoid build up of paint inside - that can spit out in clumps.  Make sure the needle point isn't damaged, as that too can cause spitting.  Also be certain the moisture trap is working, and no water is entering the airbrush proper.

regards,

Jack