This is the first post in a series detailing a woodworker’s portable spray booth that I’ve built. The design is based Michael Dresdner’s post on Fine Woodworking. I thought I had some original ideas to improve on this, but then I saw Jeff Jewitt’s book Spray Finishing Made Simple. You can build this booth for about $160 with supplies from your local big box store and scraps laying around your shop.
Application Techniques & Finish Choices
There are three main ways that I have applied finish in the past: brushing, wiping, and spraying.
I started, like most I think, brushing finishes. That’s never really given great results – the finish ends up too thick, with deep brush marks. This was early in my woodworking so I’m sure my material choice, surface prep, and brushing technique were problematic. I get much better results now, but don’t enjoy brushing and everything that goes with it.
In recent years, I’ve been applying wiping varnishes a lot. Oftentimes I’ll apply oil, then multiple coats of shellac, and finish with few topcoats of wipe on poly or Arm R Seal. On the downside this still takes multiple days, the rags have to be disposed of properly, and you’re required to store flammable chemicals. The upside is that there isn’t a lot of equipment required and the results are great with this tried-and-true technique so I’ll continue to use it.
I’ve also sprayed finish (including water based paint) with my Little Critter. it works great and doesn’t cost much. It can be a bit fussy and creates quite a cloud, and the guys at WTO made fun of it too. For small projects and with the right finish it works well, but isn’t right for large projects. I only use this with water based finishes though, because I don’t want to create a big flammable cloud in my shop. Polycrylic sprayed nicely and produced a smooth but plasticy finish.
Earlex HVLP and a Spray Booth
I’m pleased with with wipe-on varnishes so it’s time to upgrade my spray finishing tools, materials, and results. Last year my wife bought me an Earlex HV6900 which is a great unit. I’m applying more professional product like Enduro Var and working on bigger projects. With the Earlex and Enduro Var I have a great finish that isn’t flammable and cleans up with soapy water. So I’ve got the right material, I’ve got the right sprayer, so now it’s time to spray in the right place – a spray booth.
Inside the spray booth, it’s important to have a turntable. This lets you spin the work, instead of walking around it, and allows you to have linear airflow. The idea is to have fresh air flowing from behind you to the furniture in front of you. It’s also a good idea to keep the spray unit behind you in the fresh air. Any finish that doesn’t make it onto the furniture moves away from you, into the booth. This is cleaner for the user, keeps the finish from clouding in your shop, and since all spray is moving toward the finish, you get a better application. The turntable below is based on Dresdner’s. It breaks down flat, is easy to move because it rolls, and it’s sturdy.
Step 1: Build braces for the top and base from half-lapped 2x4s.
Step 2: Cut two circles out of plywood for the top and base (these are 42” diameter)
Step 3: Mount the braces to pipe flanges and screw pipes into the flanges
Note that the pipes are sized to fit one inside the other
Step 4: Screw the circles to the top and base
Done! you have a spinning, sturdy finishing turntable that breaks down flat when you unscrew the pipes from the flanges.
Leave me a comment and let me know:
- What finishes are your favorite?
- What are your application methods?
- Do you worry about a flames or fumes?
- What are your tips, tricks, or safety concerns?