spray booth explosion

[Bowtienutz]

I found this on the Model Truck discussion board. We’ve all heard stories of this happening. Anthony encouraged me to forward this.

From: MTDG@yahoogroups.com [mailto:MTDG@yahoogroups.com] On Behalf Of Anthony Oteri

Sent: Thursday, February 18, 2010 6:07 PM

To: MTDG

Subject: [MTDG] Spray booth story, sad story

I know this topic has come up in the past but it needs to be discussed again. I friend of mine built his own spray paint booth from a kitchen stove exhaust hood that he was using in his garage. Last night he was using it when it caught on fire. He has burns on his chest, arms, face and head. His wife told me he has no eyebrows, eye lashes or hair left on his head. He also wears contact lenses which melted in his eyes from the fire. He's in pretty bad shape and was transferred to a Shriners burns hospital in Boston. He was using Testors rattle can enamel on an airplane model that he was building. His wife told me she herd a boom sound then a scream. When she opened the door into the garage his shirt was on fire. Luckily there daughter's boy friend was there and he used a fire extinguisher on him to put out the fire. If anyone is using a home made spray booth don't use it anymore. The fan motor windings are exposed and will ignite paint fumes and vapors. You need to use a motor this is in a vapor proof or explosion proof case. This guy Dennis is 47 years old and is a pipe fitter by trade, ironically he installs fire sprinklers. I didn't intend to ruin anyone's dinner, but I hope it may help save yourself from getting hurt, or worse. Sorry for the gloom and doom, be careful!

Anthony

[modelhut]

Anthony, thank you for posting this. It is not something I would have thought about when I get to building mine. I will pray for Dennis, and the doctors and nurses that are treating him!

[VW Dave]

I genuinely feel bad for the guy, and hope he makes a full recovery.

If anyone is using a home made spray booth don't use it anymore

built his own spray paint booth from a kitchen stove exhaust hood

I'll continue to use my homemade booth, thanks. I hate to say it, but his choice of equipment was the cause of the accident; a kitchen exhaust fan isn't normally subjected to flammable vapors, so their exposed windings are not an issue. A brushless fan motor will help prevent such an an awful thing from happening to anyone else

[george 53]

I use a bathroom fan exhast motor in mine. Is IT safe? Where do you get a BRUSHLESS fan motor from? And HOW MUCH does one cost?I been usein mine for YEARS,but Lord knows I don't wanna blow my house up!!!

[george 53]

Dave, I've been useing a 80 CFM Bathroom fan for about 10 years with NO problems. So I'm ASSUMING it's the right type, But you know what they say about assuming something. I just wanted to be SURE.

[mikemodeler]

This is some terrible news to hear and I too hope the man makes a full recovery.

There have been many articles written in magazines and how-to build your own booth posts in this forum and others. What I truly remember being the most important issue was the use of the right type of exhaust motor. I remember an article from Fine Scale Modeler that referenced a specific type of motor sourced from Grainger Supply and it cost around $80. While some of us are frugal and try to be resourceful, I think we all agree that $80 for the correct type motor is cheaper than a trip to the emergency room!

I have seen a small, inexpensive portable spray booth advertised at Model Expo for around $125 and am thinking about that as my next investment. I currently spray out in the garage in a homemade wooden booth with no fan and I know the Mrs. would appreciate a real spray booth in its' place.

There are many options on spray booths, and given the price of kits these days, it really boils down to the cost of 10 kits, maybe less, depending on which one you choose.

Mike

[Jordan White]

I don't have a spray both seeing as I just spray outside (I use spray cans), but wouldn't a couple computer fans work (not to mention they're pretty cheap), or wouldn't they move enough air?

[Kris Morgan]

Thank you for posting this. Sometimes we all need a reminder. I do hope the fella makes a full recovery. The part of the contact lenses melting sounds very scary.

[george 53]

Ed Shaver hooked me up with the right guys to check with. I'll do that now. Thanks Ed!!!

[coolplastic]

You can find a paint booth for $125.00? Is something you can find online?

[trogdor]

More importantly, people should be using respirators and safety glasses.

[mikemodeler]

You can find a paint booth for $125.00? Is something you can find online?

There are several sources for spray booths, depending on your budget.

Micro Mark www.micromark.com

Pace Spray Booths www.pacepaintbooths.com

Model Expo www.modelexpo.com

Testors www.testors.com

Many of the airbrush companies sell them as well, do a google search on airbrushes and you will get a ton of sources.

Research and see what your budget allows. Building a homemade booth is fine, the key is the correct type of motor to prevent an explosion.

Mike

[coolplastic]

Mike thanks for the info. I had plans to build my own but I will check these sites out also. I never even thought of the dangers of an explosion. My thoughts and prayers go out to him and his family.

[Jon Cole]

Pace Spray booth ( www.pacepaintbooths.com ) for me! I don't remember the cost (it was a gift) but I know it was under $200. (now the price is $225.) and less $$$ than MicroMark booths. Also I can buy replacement filters at any hardware store. Stainless steel is easy to clean up, but I cover the inside with Glad "Press 'n Seal".

[VW Dave]

My homebuilt booth uses the same filter as my furnace, so I bought them in bulk.

[Chuck Most]

you know George, a bathroom fan could be exposed to flammable gases on a regular basis depending on your diet and regularity

I've seen guys use old box fans. I steer far clear of those knuckle-draggers. That seems just tempting an explosion to me, and I really don't want to be involved in an explosion! Life may suck... but the alternative is unacceptable.

[CAL]

I use a bathroom fan too, but they are not explosion proof certified. You'd have to get a XP certified motor. I have not been able to find an XP Cert bathroom fan, or any fan assmebly small enough for my booth. All the certified units are huge 12" and up and are starting at $500 + for a certified unit.

But then technically you should have all explosion proof lighing, wiring, switchs and a static mat oh and probably a suit and resp, and an equally protected cleaning station.

Edited February 20, 2010 by CAL

[Marc @ MPC Motorsports]

Precisely why I bought a Pace Paint Booth. Nothing more to add.

[Guest Gramps-xrds]

The only way a fan motor can cause anything to ignite or explode is for it to have brushes. Most motors now days are induction motors and there's no sparks involved, only magnetism . The windings have nothing to do with causing anything to ignite. I've been using a bathroom exhaust fan for 20+ yrs. Occasionally you might have to take it apart and clean the paint build up off the armature and stator and oil the bearings.

[Karmodeler2]

Hey Guys,

Just to clarify something that I think has been lost in the "filter" talk and the like.

The fan motor, yes the fan motor, needs to be SEPARATE from the path of the air flow. You can get these from Grainger or other places like them. The fan blades need to be moving air from the booth to the exit point without EVER passing through the electrical motor or through the windings on the motor. Almost all of the bathroom fans draw air across the motor (and it's wiring, and it's power source.....I.E. Electricity). This is the part that is unsafe and where most explosions occur. You motor should be in what looks like it's own casing attached to the casing holding the fan. It should be something similar to the water pump on your car. The pump is encased and separate from the fan and the shaft that holds it. I know, the blades are not encased, but you get the point. If you are shooting automotive paints, especially the high VOC ones from like PPG, you are only playing Russian Roulette. It will blow up sooner or later. I hope this will help with preventing future explosions.

And the price of just about ANY motor, has to be cheaper than the cost of the hospital visit, time off from work, embarrasment and the like!

David

[Crusader101]

I guess I'm safe....I only paint outdoors

[CAL]

The odds cannot be real good that you'll blow yourself up twice in your lifetime. Since I have already blew myself up once with something else - stupid. I think my odd have greatly decreased it wont happen - again. So I think I am safe too.

[Aaronw]

You don't need an explosion proof fan unless you are building a room sized spray booth to paint 1-1 cars, but it is advisable that you use a fan as David described, where the motor is out of the path of the air flow. These are typically called Squirrel cage or shaded pole blowers. Beyond the type of fan you want to make sure you have adequate airflow, the real danger is accumulating vapors.

Almost all of the commercial hobby booths use the same fans you can get from Grainger, and none that I've seen use an explosion proof fan. You can build a perfectly safe booth yourself, just buy the right stuff and don't go cheap.

There are lots of people out there using box fans, bathroom fans, stove hoods etc who haven't blown up. It really is a perfect storm event of having just the right air to vapor ratio, and an untimely spark for an ignition source, but it just takes once to ruin your day.

[Aaronw]

The odds cannot be real good that you'll blow yourself up twice in your lifetime. Since I have already blew myself up once with something else - stupid. I think my odd have greatly decreased it wont happen - again. So I think I am safe too.

I'm sure this guy thought the same thing the first 6 times he was struck by lightning.

http://en.wikipedia.org/wiki/Roy_Sullivan

Edited February 20, 2010 by Aaronw

[Guest]

A bathroom fan is NOT explosion proof!! You need to have the motor OUTSIDE the air stream. The photo of the booth above has the right type. You can get them at www.grainger.com. I built my own booth, and bought one of them, a 494cfm one. They aren't cheap, and that is why premade booths are spendy.