Spray Booth for the Cedar Valley Railroad

The move to the new location left me without some means of exhausting dangerous paint fumes (read Floquil) when using my airbrush. I considered allocating a corner of the adjoining garage but realising what dust could do to a freshly painted model if the automatic door was inadvertently opened led me back to the new train room.

I found a spot under the layout which, although offering only 1000mm clearance from the floor, by using a 635mm high card table as a bench, gave me a little under 365mm for the height of the proposed booth. A former office chair at its lowest elevation would then provide a comfortable working position.

Unfortunately, the household electrical box was directly behind the single brick wall of the room so exhausting horizontally was out of the question. Then at the local recycling centre, I found 2 pieces of 160mm plastic stormwater piping joined together by a 90-degree plastic elbow. Although I was concerned the bend would impede the airflow somewhat I accepted that by cutting a 160mm circle in the floor I would have a convenient way to exhaust the booth.

Photo 1

I had previously identified a suitable fan. Although all the experts advise that the fan motor must be out of the airflow for safety reasons, I could not afford what was available and looked for ceiling exhaust fans. All but one were unsatisfactory, either because of poor airflow or, more importantly, because the motors were open frame types offering no protection whatsoever against igniting volatile paint fumes.

The one exception was a New Zealand made 200 mm Mistral ceiling exhaust fan with an enclosed motor and a very efficient 8-blade fan. Although dearer at around $52 this proved to be a very effective choice.

Photo 2

The box itself is made from 13mm chipboard I had in the scrap box, screwed and glued together with all joints sealed with silicone. The internal dimensions are 430mm wide X 300mm high at the front, a depth of 355mm and a rear panel 300mm square. An appropriately sized hole was first cut in the rear panel to take the fan with the supplied fan fixing bolts and flanges being rejected in favour of 3 plastic electrical saddles screwed against the fan flange from inside the booth. (Refer to photo 1)

To reduce the projecting larger diameter rear of the fan to the 160mm rainwater tubing I simply used a 95c plastic bucket with a 160mm hole cut out of the base with the flange of the bucket siliconed and screwed to the back of the rear board. (Refer to photo 2)

Photo 3

By sliding the booth with fan and bucket towards the piping previously positioned in the floor, I was then able to fix the piping to the wall with a suitable bracket. (Refer photo 3 This also meant that I could simply withdraw the unit for maintenance (unlikely) or to access adjoining magazine storage.

A 20-watt fluorescent tube located directly in front of the unit took care of lighting.

In use, I have found the setup to be very quiet and efficient. I did initially use an air conditioner filter in front of the fan but found that it impeded the flow enough to result in some kickback of fumes.

Now, when Toni transits the room between the garage and entry hall, it is rarely that she asks if I have been painting. That’s how well this set-up has worked out.