Originally Posted by 302 Z28
Standard H&V filters will work, just don't use the cheap fiberglass looking ones, they won't stop squat. I would use some high quality 3M filters.
66Restomod, good site on your booth. I have one of those canopy's in 10 X 20, never thought about using it as a booth though
Important to use the box fans to push
air in and not to use them to pull
air out. Box fans have induction motors that do not produce sparks, but the switches sure do.
You are right about both the filters and box fans. The odds of a box fan setting off an explosion is probably small but not worth chancing.
I found it was actually better to pressurize the enclosure with a positive pressure by blowing air in. That way all the incoming air must pass through the filters. If you have fans sucking air out, there will be unfiltered air leaking into the booth from cracks and seams.
I used pleated furnace filters and not the "see thru" type on the box fans. They were 6 bucks each and worth it.
Here is the link again with pictures, how we built it, tips that I learned as well as some safety considerations. Remember, Safety is No Accident...