Prepping the model for spray painting

I have a few questions regarding spray painting:

  1. What are the best practices to ensure an even coat of paint without wrinkles or inconsistencies? (Just some background: I had been working on my last model (the MPC 1:25 Knight Rider kit) for about a month, really focusing on the interior and the chassis, some of my best work tbh, really happy with how that turned out but when it came down to spray painting the body, which is really what will make or break the model imo, I remember watching in horror as the spray paint began wrinkling right before my eyes and I could do nothing about it… when it dried I tried sanding it off and respraying it but it wrinkled again and by that time it just looked awful… unrecoverable at that point… later, when I was doing some research I read that it most likely wrinkled because Ithe coats that I was spraying were too thick… though I’m not sure if this was the cause tbh)

  2. Should I wash the model in soapy water and wet sand it before I spray paint?

  3. Will very small scratches/ stress marks/ sanded places show up after spray painting? If they do, should I sand them, or use some other method?

  4. Any general spray painting tips?

Washing models before painting is always wise. Your hands impart oils and junk and there can be fine residues left over from sanding. Warm soapy water and plenty of time to dry. I’ve also had good luck spraying down with windex and then rinsing.

You’re going to end up with water trapped in places, so it can help to spay out with an empty airbrush or a hair dryer (cool air only!).

There’s no need to sand the entire model unless you’ve got major blemishes.

They might. Depends on the depth of the scratch and the thickness of the paint. Mr. Colour makes different grades of primer for this reason. 500 is like paste for big boo boos, 1500 shows off every flaw. It really depends on how clean a model you want in terms of sanding and filling. With a car, you’re obviously going to want it less beat up than a tank.

Nothing other than the usual, lots of thin coats and try not to get so close that the paint puddles (you’ll get bubbles and runs) or so far that it dries in the air (orange peel/grainy texture).

I don’t do cars/glossy models, so I’m less particular about finish, but I also only use rattle cans to occasionally prime or top coat.


Thanks for the quick response, I did have one more question though: Is it a good idea to use lacquer spray paint? Actually, what’s the difference between normal and lacquer? It seems to me like lacquer would have a smoother and shinier result… but I’m not that experienced tbh. Edit: Also, is “Mr. Colour” and “Mr. Surfacer” pretty much the same thing?

I have never washed a model in 23 years,either a good lacquer or enamel primer makes the difference for acrylic paint,if you are using lacquer or enamel paint,then the primer isnt always needed.But again,I have never had adhesion problems and have never washed a model.


Another question: Will I have any problems if I spray this paint over this paint?

Yea. Gunze-Sangyo makes all the Mr. Whatever products. I can never keep track of them so it all becomes Mr. Colour.

As Tojo said, Lacquers or Enamels tend to give better coverage and adhesion because the chemical solvents tend to bite and bind better to the plastic vs an acrylic paint.

And no, Tamiya will spray fine over the Rustoleum. Just be careful with the primer. It’ll cover really well and will do a great job at hiding surface imperfections, but it goes on thicker than say Tamiya and it can be easy to fill in fine details like panel lines.

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Exactly; I spray my armor with Krylon primer and then use Tamiya or AK over that.

As long as the spray paint is allowed the proper curing time you can put pretty much whatever over it.

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Gently washing the model in warm soapy water is very important in my experience. Getting the dust, dirt and oil from ones fingers off of the model promotes a better base for building a good finish.

Some of my friends just blast the model with air from the airbrush to blow the dust off etc. They also tend to have blemishes in the paint that need touch up after picking dust specs out of the painted model.

Getting the model dry can take a while. Airbrush can help by blowing water out of recesses.

A paint area that’s clean and dust free also helps. I tend to keep the painting area in the hobby room very clean and wipe dust etc before painting.

Clean works to your advantage in my opinion & experience.


I totally agree with your comment about a clean dust free environment, I try to keep my work area spotless. It’s surprising how dusty things can get, even if you only have a couple of days without doing anything.


I’m also in the “wash before painting” crowd for all of the reasons cited above.

I use a sink full of slightly warm water with a few drops of dishwashing detergent. I submerge the model, sub assembly, or part and use a large watercolor brush to gently agitate the surface.

An alternate method is to use a spray bottle of glass cleaner. Spray the model down with this, then give it a dunk and swish-swirl in the warm water, rinse it off and let it dry. This may be safer if there are a lot of very delicate details that could be damaged.

Using a plugged sink is a good idea in case I drop something or break something off. I carefully check the bottom of the sink before I drain it just in the event that I missed something.

I rinse well in slightly warm running water and set the washed parts onto a clean paper towel to dry. I plan my painting and finishing routine to allow me time to let the parts dry overnight. Still, bowing them off with a dry-empty airbrush (i.e., just compressed air) will sometime bring out drops that have been trapped in small recesses or holes.

Since I started doing this (years and years ago), I’ve never found that I needed any sort of primer to improve paint adhesion. (Primer’s occasionally useful for other reasons, though.)