Thursday, November 29, 2012

Inexpensive & Easy Down-Draft Spray Paint Booth

I've spent some time on-line looking for a suitable spray paint booth that won't break the bank while at the same time protecting the surrounding area from overspray.  Nothing I've come across on the web suited my needs or my budget!

I came up with a simple design that allows me to use inexpensive spray primer (Krylon) or my air brush indoors without any overspray and without an over-sized light-blocking hood!

Maelstorms Indoor Down-Draft Spray Booth

Materials required: 

$10.00  20” x 20” 3-speed Box Fan (Home Depot/Lowes Sale!)
$  8.00  Wire Shelf
$  7.00  20” x 20” x1” Filter (2 each at $ 3.50)
$  2.00  20” x 30” Foam Board
$  0.00  4” diameter paper disc cut from a cereal box
$  0.00 Fresh fruit container (recycled)

 $27.00 Total cost
The cost will drop below $20 if you have another way to keep the fan stable and 12+ inches off the floor (2 old saw-horses would do nicely for the garage!)

Place wire shelf on suitable surface near an outlet.

Place 3-speed box fan on the wire shelf with the speed control out, fan air direction = down

Safety Step -->  Cut a 4” diameter (approximate dimensions) circle of cardboard and place it over over the fan motor windings (to prevent the possibility of paint from being drawn into the electric motor). 

Place one of the 20” filters over the fan with the flow direction pointing down

Place the second 20” filter over the first with the flow direction pointing down and the filter folds running perpendicular to the first filter (left to right vs. front to back)

Cut a 20” x 15” section of foam board for the back, use the remaining foam board to make the sides. 

Place the fresh fruit container (or suitable stand-off) in the middle of the top filter

Plug it in, turn it on “high” and you’re ready to paint!  After painting, leave the models on the stand-off and set the fan on “low” the models will dry much-much quicker than normal!

If you are more sensitive to the paint fumes use a Bacterial Grade filter ($15-20) as your lower stage and it will significantly reduce the fume-factor. You'll replace the upper (inexpensive) filter every full can of spray primer or two, the lower one will last for quite a long time!  Filtrete has a couple of different ones with Activated Carbon filtration which removes odors such as: pet, smoke, cooking, mildew, and cleaning chemicals.  It's up to you and your wallet to decide what you want to get.

I've primed/painted 100+ marines, 4 vehicles, 4 fliers as well as 100+ Secret Weapons Miniatures bases and I've finally swapped out the lower filter - just because it wasn't pretty for the photos, not because it was clogged or restricting air-flow!  I've only gone through 3 of the upper filters.

It is amazing to watch the spray paint cover the model, travel about 2 inches beyond the model and then get drawn straight down into the filter!

Give it a try and let me know what you think!


  1. Interesting, will have to set this up when I start on my Imperial Fists, at least I think they will be Imperial Fists. :)

  2. What is stopping the paint from being sucked down prior to the model? If nothing, does this result paint traveling down as it hits the model to some degree?

    1. If you spray from too far back you can see some spray heading down. You quickly adjust to spraying a touch closer or change the speed of the fan!

  3. Replies
    1. Stormtalons, Stormravens and several FW fliers! Lol

  4. Much more intricate than my box on a garbage can in the back yard.

    1. The temperature here at 5,000 ft is cool enough already that I had to move spraying indoors!

  5. I just bought the filters. Only change I'm making is, I'm going to make a back exhaust instead of a bottom. That way I still have a nice workspace to paint or airbrush on.

  6. I am going to try for a rear exhaust as well when I finish putting mine together. Also, going to use cardboard for the sides as that is what I have handy.

  7. Back draft should work well. Just use masking tape to hold the filters and sides in-place! I went with bottom draft as I wanted gravity to assist with excess paint removal. Let me know how it works!

  8. this may make it so my GF can finally prime her own models since it wont bother her asthma!.