Replies

1. 
   Kevin_Getchell | Mar 29, 2001 01:54pm | #1

   *
   Hey Ken,

   FWW did a short piece on a simple spray "booth". I cant recall which issue it was in though.

   I believe is was just a reworked cardboard box that was attached to a fan in a window like you are thinking.

   It should work fine...be prepared for a fan with lots o'color character and or gloss! A simple 3 speed box fan should be plenty powerful enough...assuming the fan is in the window itself.

   You may want to make sure that your exit area is free of objects you do not want to finish by proxy!

1. 
   Ron_Teti | Mar 30, 2001 04:52am | #2

   *KenThe type of fan would depend on what and where your spraying. If you are spraying laquer in the garage kind of enclosed then definately go with an explosion proof fan. If you plan on spraying out doors or water base material then just about any good fan would do.

1. 
   Don_Stephan | Apr 02, 2001 01:20am | #3

   *Based on articles in FWW I built a "booth" using 3 sheets of 1.5" x4' x8' blue foam with a fourth for the top. Join them using inexpensive removable pin hinges.

1. 
   ken_chase | Apr 04, 2001 12:33am | #4

   *Don:Thanks for the help. I'm not familiar with blue foam. Is it a type of rigid polyurethane? Where can it be purchased? Is the pin hinge you suggested the standard type hinge used on shutters with a removable pin? Do you use this with an exhaust fan?Appreciate your imputKen

1. 
   Don_Stephan | Apr 09, 2001 02:22am | #5

   *Wanted lightweight but fairly sturdy sheets. Local Home Depot had both white and blue colored foam insulating sheets. Blue was more expensive but more rigid, the white seemed like it might snap in two rather easily.For an exhaust fan, using an old direct drive furnace blower enclosed in a plywood box. 1/4" hardware cloth across the opening, then can use furnace filters (expensive) or pieces of HVLP filter found at an HVAC supply center in bulk.Saw a suggestion elsewhere that since overspray is heavier than air, the closer to the ground the exhaust fan the more effective it is.The hinges are an inexpensive Stanley brand utility hinge, look just like a smaller door hinge. Just drilled through the foam and attach the hinges to the foam with machine screws, using a large diameter washer under the nut. Mark for the hinge locations with the sheets taped into position.The fan is on a kitchen cabinet on casters. My sprayer compressor is a small Emglo which I keep in the bottom of the cabinet.

2. 
   Jim_Nation | Apr 23, 2001 02:05am | #6

   *Although it is unlikely, there is a possibility of explosion if you use an exhaust fan not designed for paint booth duty, particularly with nitrocellulose lacquer. The fan should have a non sparking impeller, aluminum, bronze or plastic, be direct drive with a TEFC explosion proof motor or have the motor outside the airstream.

3. 
   Kim_Carleton_Graves | Apr 25, 2001 02:59am | #7

   *Hi Ken,Before I answer your question directly, I'd like to address the issues surrounding spray booth design and expand on Jim's warning.While it's true that a good spray booth will provide you with a superior finish, the primary use of a spray booth is fire prevention. In order to have a fire you need three things: fuel, oxygen and a source of ignition. The cloud of over spray bouncing off the workpiece creates a very flammable environment because the fuel is atomized with a large amount of oxygen. Any small spark (even accross the room) can ignite the over spray causing a fireball. So the function of a spray booth is not just to remove the over spray but to provide a fireproof environment without any source of ignition. Fireproof lights, motors, switches are necessary. It is very dangerous to spray flammable products like shellac and lacquer without the fireproof protection of a spray booth that is up to code.The second function of a spray booth is to capture the toxic byproducts of spraying. While water-based lacquer is for all intents and purposes nonflammable compared to nitrocellulose-based lacquer, it is still very toxic. Spraying in your basement and venting to the outside with a window fan will do nothing to capture the toxic byproducts of spraying. Indeed anything you do vent is just going out onto the lawn. And the rest is left in the basement and spread through the house. The only non/low toxic finish that is good to spray is shellac. But alcohol is flammable which takes you back to the fire issue.The third function of a spray booth is to provide an environment where you can get a good finish. Not only must you vent the over spray before it falls back onto the work piece but the environment must be clean. Spray booths that are up to code have filters not only on the vent out, but they filter the air coming into the spray room to keep the air in the room clean. The sort of spray booth being talked about here doesn't do this.So what's my message here? I think the promise of spraying for the hobbyist is a false one. One can rationalize and say "well I'm only going to do this once or twice or three times a year so how dangerious/toxic can it be?" Maybe that's true. But there is a very good alternative to spraying: hand-applying finish with a brush or pad. Spraying is advantageous in a production environment because of its speed. Lacquer dries very quickly and that combined with the speed of application makes production finishing relatively cheap. It's also true that you'll get a "superior" finish if it's sprayed - but only if you have a spray booth that's up to code (no one tells you that part of the equation!) For the hobbyist, hand applying shellac, oil, lacquer, or varnish based products provides all the finishing capacity you really need. It is safer, much less toxic, and will give you good results that have stood the test of time. At the beginning, I promised to answer your question - No it won't work: not really. Hope this helps.Best,Kim Carleton GravesCarleton Woodworking