[Rod and Custom]

I was going to comment about fire hazard and paint booths. Common sense is the best safety equipment. As the other comments stated, stupidity leads to accidents and fires. The standard spraying operation is not all that dangerous. Think about it. How much solvent would you have to evaporate into the air to achieve a volatile air/fuel ratio? As long as you have airflow through the spray area, you shouldn't have a fire hazard. That is, if you don't light something on fire in the process.

Keep a good fire extinguisher(s) near the exit(s). Why there? So you can decide whether to go back and fight the fire, or RUN!


Reflected edges in the sprayed surface are the best way to determine wetness and flow. I've seen PDR guys put lines of tape on their fluorescent lights, so they can see the surface. When setting up paint booth lights, make as many edges as you can. Photography lighting uses diffusers to eliminate hard lines and shadows. We want the opposite when we spray.

[Lizer]

Originally Posted by Rod and Custom

I was going to comment about fire hazard and paint booths. Common sense is the best safety equipment. As the other comments stated, stupidity leads to accidents and fires. The standard spraying operation is not all that dangerous. Think about it. How much solvent would you have to evaporate into the air to achieve a volatile air/fuel ratio? As long as you have airflow through the spray area, you shouldn't have a fire hazard. That is, if you don't light something on fire in the process.

Keep a good fire extinguisher(s) near the exit(s). Why there? So you can decide whether to go back and fight the fire, or RUN!


Reflected edges in the sprayed surface are the best way to determine wetness and flow. I've seen PDR guys put lines of tape on their fluorescent lights, so they can see the surface. When setting up paint booth lights, make as many edges as you can. Photography lighting uses diffusers to eliminate hard lines and shadows. We want the opposite when we spray.

I've been traveling so really hadn't had a chance to respond to this until now, even though I saw it come through in my email.

I too was thinking the same thing as what you pointed out...I'll have air in and air out...in order for a spark to ignite I'd have to have a really thick haze in there. Common sense as you say...

Was wondering if you could expand on how to make as many edges as possible....?

[oldfart952]

hi bud, got to give my 2cents worth. first make sure that you have enough room top to bottom. what if you got a truck to paint???them insulate it after u wire it. then sheet rock it. heats very preious you'll need all you can get. i painted out of a barn,no heat made a stall out of plastic but i did have an explosion proof fan. i painted there for 4yrs. jobs came out **** !!!!! lights i got 12at home depot 8 on top one in every corner. keep them on. good luck bud i'll help ya anytime !!

[Old Fool]

A fire extinguisher is always a must have in any shop, vehicle, or whatever.

Chances are if your paint booth were to have a fire the extinguisher will do little to no good.

When air in the booth reaches the LEL of the solvents being sprayed and
IF there is an ignition source then you have a BOOM or flash fire, then maybe fire.
Most likely You probably won't be in any condition to use the extinguisher at that point.

The LEL for urethane clear is around 1.0 and the UEL is around 13.1.

That means if the atmosphere in your "booth" is 1% urethane than it is possible to have ignition.
If the atmosphere is above 13.1 urethane then the mixture is to rich to ignite.
Anywhere in between will ignite.
This information is available in the MSDS sheet for any chemical you use.

[Old Fool]

I too use the homemade spray booth and have thought a lot about ignition sources.
Box fans are not to high on MY risk list, they are a brushless motor- so no sparks from a commutator & brush assy.
Blades are plastic so no risk of sparks being generated there either.
IF a bearing were to fail then there is a risk of sparks.
BUT- the switch sparks every time you turn it, set it where you want and leave it alone.
Connect your fans to extension cords that are plugged in somewhere else outside of your booth.
Plug and unplug the cord at that location to turn the fans on and off.

Lights: I use auxiliary fluorescent lighting, the risk of sparks at the connection of the ends of the bulbs and the sockets is a concern to me.
I make sure there is no corrosion on either, then I apply some dielectric grease on the contacts before installing the bulbs.
I only spray a couple times a year, so I check and service them before each "booth setup".
I plug my lights into extension cords and do the same as the fans, plug and unplug from outside the "booth"

Air compressor: big risk - keep in another area, there are pressure switches,metal pulleys,magnetic starters, etc.
Needs to be in a remote location.
( not to mention it might be blowing oil vapors into your booth air)

Thermostats, the old contact type are a spark risk.
Solid state not a problem normally.
If either were to short out and burn up they may provide an ignition source.
I turn off at power source.

Garage door opener: possible source, unplug it.

Light switches: Danger Will Robinson! they arc internally darn near every time you turn them on or off. I turn them on before starting and do not turn them off until my "booth" is totally cleared out.

That is my routine, not saying it is safe or unsafe, just my thoughts for my "booth"

[johnnyg]

We built a small paint booth (for a wheel re-finisher) we put a restaurant type exhaust fan on the roof to draw air out.

[Lizer]

I see this thread has come back to life. I never got around to constructing the booth this summer as I was too busy with other things, but I would still like it to happen and the most recent comments have given some good info.

Yes I always do keep a fire extinguisher in the shop, no I don't think it will help me if my booth explodes, and yes, sparking is a concern of mine. I also do not plan to heat the booth as I only paint/spray in the spring, summer, and fall when the temps are warm enough.

[bob wilcox]

I've built four booths, the first was a "not very good one". The last three were cheap and great. A spraqy booth should be 24 by 14 feet. The height should be 10 feet if possible. I framed them with metal studs--2x4--on 16" centers. at the door openings i doubled the studs, one inside of another, I used 2x6 metal studs on the ceiling on 12" centers--it doesn't cost that much more for the strength gained. I used wind braces for diagonal support. I lined it with white barn metal, not galvinized because of the weight. Run the metal horizontally and caulk the heck out of it as you install it. For the ventilation I had the fans [3] with air ducts and filerts about 6 feet from the booth and ducted the air into the ceiling corners and the center corners of the ceiling. The exhaust was through two ducts under the area where a car would sit just laying on the floor. The were heat ducts made to go inside of walls of a house, an oval or rectangular shape, they make both. these ducts were parallel and running lengthdwise nearly the full length of the car. They are made to go in a 3 1/2" wall, so they clear most cars. If they wont clear, lay 2x6 boards on the floor to drive in on and raise the car 1 1/2". cut about 3" holes in the side of the ducts for the air to go through' four per outer side of duct. Install duct work on the ends of the booth for these to slide on to. Don't make this a perminent attachment, leave it so that the ducts can be slid off of the ducting at the wall when not in use. Now you have a pressurized booth that wont draw dust and oil in when in use. Place your lights verticly on the walls so that they extend at least a foot above any car you are painting. put he ceiling lights cross ways in the booth [3]. Put the end lights about 2 feet from the end of the booth. You can add more lights, the more the better.
A good and cheap place to get lights and studs, and even a walk in door is Your local Home For Humanity outlet. Construction companys donate materials and you can get it for cents on the dollar, and the best part is that it is a tax deductable contribution. Hope this helps someone!

[oldfart952]

ya bud sounds sweet.but your hot air ducts will they cause the paint to dry in these duct holes first ????? one more thang to much fan works blow it'll suck your heat out so fast it won't stay warm.yes there's a fornual for what size fans u need . no **** i had a 36" fan on a 12'x14 high door it got cold !!!! just check it out. hey take care bud pops

[Lizer]

I scored a free fan from an old body guy that used it in his home garage to spray. He took a squirrel cage furnace blower and put it in this enclosure with filtered inlets on the top and front. It's belt driven by the motor on the side there.

Is this type of AC motor brushless? He just sprayed with the entire thing in the room, and had ducting that took it out the roof. I'll run my ducting out in a similar fashion.

Second, do the cheapie utility lights with exposed bulbs have issues with the bulbs getting coated and covered in overspray?

Third, I'm trying to figure out how to mount the lights on the side walls in terms of running power to them. The lights will have a cord that plugs in. If there were actually outlets in the booth for the lights to plug into--and outlets either had a light plugged into it or one of those outlet baby-proofing protectors you plug into it, would this present a serious risk? I ask because people mention plugging lights into extension cords and this is the same thing, it's just an outlet, not extension cord.