by Ron Joseph
July, 2006
Portable Spray Booths
Q. I came across the following system: http://www.mobilepaintbooth.com/portable_paint_booth_home.html
We are furniture wholesalers and we have the need to get a portable spray booth or contaminant capture system for refinishing our products. We sand the surfaces following repairs, and spray with solvent-based lacquer. Our biggest table is 8x4 ft. We need to produce high quality finish and at the same time we want the process to be safe and less intrusive (in size or noise). It would be ideal if we can find a system that doubles as a sand-dust and overspray/contaminant capture.
Particularly, I am concerned about the air flow and its effect on horizontally placed flat surfaces and any impact it may have on the spray pattern.
A: In my opinion, and this is strictly my opinion, the type of portable booth you've described is useful for small jobs where you need to be able to spray apply paint in an area where others are working, or where it is not practical of feasible to build a dedicated spray booth. The booth you've described does have the potential to draw solvent vapors away and exhaust them to the outside air. With regard to the capture of paint particulates I am skeptical because, based on my experience with similar spray capturing equipment I have found that the air velocity is too low to carry the particles over distances of more than a few feet. A few years ago I conducted an air velocity profile on a similar type of device and found that while the air velocity was fairly good when measured directly at the face of the filter, the velocity dropped to zero at approximately 2 ft in front of the filter.
I don't have sufficient information about the portable booth to which you are referring; therefore I suggest that if you wish to purchase such equipment for your refinishing needs, you should conduct air velocity tests a various distances from the filters. If you find that the velocity drops to zero only a few feet from the filters, you can assume that most of the overspray from your painting operation will fall onto horizontal surfaces, such as the floor, or perhaps even freshly painted surfaces.
In summary, if you are looking for a high quality painting job, portable spray booths of the type you have mentioned are probably not our best bet.
Best wishes,
Ron Joseph
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