Spray Painting


OK, so sometimes you need a little less finesse and a little faster paint deposition. I like painting miniatures to an above average quality level, so I am most worried about not compromising the detail and final paint job with the spray approach. I wanted to paint my army of Tyranids for the sci-fi miniatures wargame Warhammer 40k. That's about 140 models, so I was eager to cut down on painting time. I decided to paint and basecoat them. Here's what I learned in the process. I was using Black Spray Primer and Dark Angels Green Spray Paint from Citadel Colour (Games Workshop).

General Technique

A can of spray paint (or sealer) basically contains paint (or sealer), solvent, propellant, and a mixer ball. Your goal is to get that paint cleanly and smoothly deposited on your models.

  • Shake for at least 60 seconds after you hear the mixer moving around - I know this is on the can, but it bears repeating as lots of people disregard it. This can be a show stopper; if the paint is not mixed up well, you cannot get a good result.
  • Take a break from spraying and shake the can for 10 seconds every few minutes to keep the paint well mixed.
  • Sweep across models - Start spraying away from the model, then sweep across it; when you start and stop the flow of paint, globs of paint or solvent can come out, marring the coat of paint.
  • Faster sweeps put down less paint, so when you first start painting or if you are using a can for the first time, sweep quickly at first until you get a feel for the flow rate. You want to find a happy medium between dusting (too fast, unless that's the effect you want) and dripping (too slow).
  • When you are finished, invert the can and spray until the flow of paint stops (propellant will still spew out). This keeps the nozzle clean; a dirty nozzle can make a can of paint useless.
  • Spray 10"-12" away, just like the can says; this is far more important than you might think (see troubleshooting).
  • Read everything else on this page.

Drop Cloths - One Meter Radius Minimum

I used some of the free newspapers distributed in the area and laide them down for about a meter around the space I wanted to work. When you are done painting, you will see what appears to be paint beyond your work area. Don't panic! It's probably jsut paint in the form of dust that can be easily swept away with a broom. If you actually are painting the ground, then you should probably extend the area of dropcloth.

Humidity - 85%+ Is Definitely Bad

I painted some models and got great results at about 70 degrees F and about 65% humidity. Then a day came along that was 85% humidity. With the same cans of primer and paint, I had different results than the previous days. Both coats, primer and basecaot, were duller. I have not tested the difference in painting over them yet. Here's a picture to show the difference.

The left model was spray painted with black primer and a basecoat of Dark Angels Green under normal humidity and temperature (70 F, ~65%).
The right model was painted the same way with the same cans of paint when the humidity was high (~70 F, ~85%).

Wind Can Be a Show Stopper

This is pretty simple. Don't try to spray where it is too windy. The paint will go where you don't want it and you are more likely to get dirt embedded in the paint on the models.

Protect Yourself - Good Ventilation, Mask, Gloves

Buy a filter mask. It's no more than US$30 and it canhave a profound impact not only on your longterm health and brain cell count, but in the short term it may prevent a nasty headache. I used a filter mask from Home Depot (a local DIY supply) that was rated for paint and pesticides (MSA Safety Works Respirator for Paints and Pesticides, Model # 00817662). It worked perfectly. I did not get a single whiff of the foul solvents while the mask was properly in place.

Good ventilation is just a good idea. You don't want to trap the fumes and endanger others, and you don't want to wear the mask all day. Be careful not to get into too windy of an area though.

Gloves are useful for masking your hands. I bought some cheap work gloves. I wear them so that I can hold the minis on the mount continuously and still be aggressive with getting the paint where it needs to go without painting my hands in the process.

Getting Good Coverage - Lots of Thin Coats From Various Angles

The simplest way to say this is spray with single smooth quick passes from eight angles, spraying up at the corners and down at the corners. Basically, hold the model(s) straight in front of you. Rotate 45 degrees horizontal and 45 degrees vertical. Spray, rotate 90, spray, rotate 90, spray, rotate 90, and spray. Now you should have sprayed up at the model from all four angles. Repeat this same process by spraying down at a 45 degree angle at the four corners. If I can get pics up, it will be more obvious what I am trying to say.

Resist the urge to make multiple passes until those coats have dried, even if you only wait a couple of minutes. If you are painting a bunch, just do a circuit and by the time you come back, the first model should be dry enough for touch up coats.

How many cans?

I averaged about 30-40 models per can.


Problem Solution
Bubbling/foaming and/or dripping You're probably spraying too close. You should spray at about 12" from the model. Be careful if when you move the can during spraying that you are not getting the model too close in the process.
Rough, gritty texture to paint.

Two possible problems:

  1. High humidity 85%+
  2. Spraying too far away. This can cause the paint to dry up into dust-like particles before they hit and you end up putting down dirty paint, in effect. You should spray at about 12" from the model. Be careful if when you move the can during spraying that you are not getting the model too far away in the process.


Last updated 2010-03-25

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