Replies

1. 
   mwestenberg | Jun 26, 2003 07:38am | #1

   Get one or two old furnace blowers, put them in the wall opposite of where you want the exhaust and turn them on.  If you don't SUCK the air out past the fan motor you won't have much of an issue with explosions or solvents etc.  Make sure you can provide some makeup air on the other side of the wall the blowers are installed in.  If the result is too drafty, make a couple of baffles to deflect the air around the work area.  The success of this scheme depends on making the room more or less air tight; forcing air in is the same as sucking air out as long as there is an exit.

2. 
   kbmunkholm | Jun 26, 2003 07:53am | #2

   Cutawooda,

   explosion proof and economical are two words that don't usually appear in the same sentence.

   Find a blower that has the motor and belt drive out of the airstream, this way, you minimize risk.

   Look for non-sparking impellers, (plastic or aluminum)

   http://www.delhi-industries.com/blowers.html

   http://www.canadianblower.com/41/Index.html

   http://www.tcf.com/

   Some schools that we have done use heat recovery ventilators for make-up air, exhaust and temperature control.

   KM

3. 
   HowardAcheson | Jun 26, 2003 07:23pm | #3

   Blow out instead of sucking out.

4. 
   JOSEPH2238 | Jun 26, 2003 09:54pm | #4

   Ditto on blowing out the fumes. When you blow air into to spray booth you will also be able to filter the supply to the blower. When you suck the air out of a booth, dirt and dust find all of the small holes in the booth, then into your finish.  When I built spray booths for a living I would ALWAYS make sure that the booth had positive pressure. It doesn't take much negative pressure usually measured in inches of water column to create a "dirty booth".

   Take care when you seal the booth so that ALL of the fumes go where you want them to go.  Also make sure that the wind will not push the fumes back into the blower inlet.

   Joe Phillips

   Plastics pay the bills, Woodworking keeps me sane!

1. 
   HowardAcheson | Jun 27, 2003 12:44am | #5

   Joe, that's an excellent point and I wish I had made it.

2. 
   Telemike | Jun 27, 2003 07:52am | #6

   Joe is abolutely right.  Industrially, virtually all clean rooms and quality spray rooms pump air throught filters INTO the room.  Then, with spray set ups, there is a scrubber or baghouse on the exit side to control emissions.

   By blowing in, the room is kept at positive pressure and air leaks OUT.  If you suck air from the room, air leaks IN and carries dust into the room with it!

1. 
   JOSEPH2238 | Jun 27, 2003 02:31pm | #7

   You can make a simple gauge to check the pressure in your spray room.  Get your self a 10' length of 1/2" or 3/8" clear/semi clear tubing. Fill it about 1/2 full of water with a little bleach (stops mold) and food coloring. Attach it to the wall in a "U" shape. One end goes in the booth, the other out side of the booth. With the fans off the water in both sides is level. If you booth has positive pressure, the water will rise toward the end outside of the booth. Every inch it rises is one inch of water column.

   It is always best to push the exhaust straight up out side so that the fumes can mix with outside air before falling back to the ground.  I would hate to hear about another liquid nails type of explosion.

   Joe Phillips

   Plastics pay the bills, Woodworking keeps me sane!

   Edited 6/27/2003 7:36:20 AM ET by Joe the Plastics Man