Jed
I have recently made a knock down spray booth. I plan to post some details when I next get it out to spray the units I have shown in this thread
https://www.ukworkshop.co.uk/forums/pain ... 39492.html.
In my case, the considerations were: knockable down to flat pack, transportable, capable of taking an 8ft wide unit/door, well sealed as it is being used initially in smallish rooms that have been finished.
I looked far and wide for examples and guidance, and the best I found was here
http://www.highlandwoodworking.com/knoc ... booth.aspx. My own design was rather different and more flexible, but this was very helpful and my construction follows the same principles.
I worked on the guidance that you should aim for 6,000 cfm on the fan - my experience so far, however, is that this is very generous as I only needed to run the fan at pretty much its lowest speed to maintain a good flow into the filter. At full speed, you can feel the breeze!
The major outlay was:
A (500mm) plate extractor fan
http://www.eltafans.com/select-axial.php and controller - approx £300 all up
Some filter material
http://cgi.ebay.co.uk/Paint-Spray-Booth ... 563711e449
One sheet of 18mm plywood and 3 sheets of 6mm
Some 21.5mm overflow pipe and connectors which form a frame for polythene which I have used for the front enclosure.
It is clear that you are confined to using water based finishes unless you can build a more sophisticated dedicated facility. I am not (yet) an expert on finishes and am still at the early stages on using the spray booth, but it has been well tested and works very well.
Unfortunately I do not have any photos of the booth erected and it will be a couple of weeks before I am back there, but I will put some up when I can.
I hope that helps
cheers