wow i had no idea so many people had great info, thanks everyone, sorry it has been awhile for me to answer. its hard to answer while at work. thanks again everyone
[}:)]
Amen!! Just don’t ask me to convert any scale measurements.[:D]
Ray
For what it’s worth - for years, I have used a home-made booth which uses a cardboard box. I got a squirrel-cage fan and a 120v motor, mounted them in a can that fit the fan impeller, cut a hole in the can to attach a dryer vent hose to the outside and cut a hole for the can to fit in a cardboard box. It worked well until I went to Harbor Freight Tools and found a booth for $50.00. Anyone wanting info on the construction, email me.
Yes… but you have to be a little careful about flow ratings…
They are ratings measured with NO load, NO extra resistence, and NO ducting. SO your actual flow rate will certainly be less than rated. It is also affected by the area where air can flow into the hood.
A lower flow rate can work very well if you restrict the in-flow area, so you don’t get fumes circulating back into the room. I do have some experience with Chem Lab hoods…
Als remember that more flow can mean more dust going thru… I put simple window screen material over my in-flow area to filter some of the larger stuff…
I too started out using the cardboard box idea. For the fan I used a blower I got from a boat supply store. Blowers are used to remove any gasoline vapors that may have accumulated in the bilge of boats with inboard engines, so I figured it was perfect for spray booth use. A 200cfm blower was pretty inexpensive. The only problem was how to power it, since they are designed to run off of 12V boat batteries (similar to a car battery) - in other words, DC. One could use a car battery (but this brings up another problem - how would you recharge the battery?), but what I ended up doing was using an AC/DC converter I got at Radio Shack, so I could plug it into a wall outlet and convert the AC house current to 12V DC for the blower. A little complicated? What can I say, I’m an engineer, and had a little fun with it! After awhile, however, I decided the blower made too much noise. In the end, I came across the December 2000 article and built a more sturdy spray booth following that. I also highly recommend getting a fan from Grainger. I did, and it’s a lot quieter than the marine blower, while moving more cfm. I think the Grainger fan was about $125, but well worth it.
What type of paints are you spraying with?
If you use acrylics exclusively then you don’t need a squirrel cage fan, you can use any fan with a filter on it.
You can even use a 20" boxfan with a 20x20 furnace filter on the front and back to filter the air going through it.
If you are spraying enamels and laquers there are also brushless motor fans that do not produce a spark so the chance of a mishap is minimized greatly.
Here is a good article on booth design:
http://modelcartech.com/booth2.htm
Mike
naplak, I took a look at your example and I am thinking of building out my booth like this. I do primarily spray with acrylics, just wondering what you do to clean out your air brush when you are done, ie. what can you run through it that won’t be flammable? I want to make sure I am safe with this thing.
Thanks.
Nailz,
You can clean airbrushes of acrylic paints with Windex or Formula 409 to go the cheapest route, followed by straight water. Both are not flammable.
There are other cleaners that work a little better but they are harder to find and more expensive.
Mike
Excellent, thanks for the tip Mike. I guess I need to go get started on my new booth then. 
Glad I could help Nailz. [:)]
Just remember that if you use enamels and clean your gun with laquer thinner the advice I gave does not apply. [:D]
Let us know how that booth comes out. [;)]
Mike