spray booth...

[Jason Raksnis]

Im planning to build a spray booth separate from my shop. Any suggestions for size and ventilation will be appreciated. thanks

jason

[Brian Backner]

Jason,

It would help to know how large of a spray booth you are planning to build. Is this going to be something that would fit on a benchtop, or an automobile sized spray painting "room" in which you will be standing next the chair/table/etc. you will be painting. What type of paint/finish will you be applying - i.e., just how toxic and/or flammable/explosive will the stuff be when aerosolized?

Brian

[Jason Raksnis]

I have a cabinet shop and im planning to build a seperate booth or room near my shop to do all my spraying and final sanding in. I spray mostly waterborne laquers but would like to spray all types of wood finishes. In what instance do i have to use a explosion proof motor? Im asking for advice on size. I have an area probably 16x24, so i have some room to work with. I plan to build it kinda like one of those prefab sheds, wheres its built on some beefy timbers as to where i can move it if ever move from my current location. I got about 5 grand to spend. any help would be nice.

[Wayne Cannon]

I followed a suggestion from Jeff Jewitt in "Fine Woodworking's" Spray Finishing book to use rigid foil- or paper-backed foam insulation panels (4' x 8', cut down to 6'8"). I made mine 8' (two panels) wide and 4' deep, with a 4' x 8' panel on top. I connect them with Velcro, planning the placement so I could opt for either 4' (one panel) or 8' (two panels) wide.

A shallow filter box on the inside of a hole in one back panel holds two cascaded 24" x 24" filters (coarse and medium), and a fan is mounted on the outside. He used a standard box fan sitting on a box for the right height. I made a pseudo-explosion-proof fan from a cylinder of metal flashing with a pulley-driven fan inside and motor outside. By the time I finished, it would have been better and less expensive to have purchased a commercial explosion-proof fan.

What would I have done differently? I would have created more filter area, still not intruding too much into the depth of the booth.

Here's a wooden version from the same book. It would be much heavier, about the same size knocked down, more expensive, and less susceptible to damage than the foam version.http://books.google.com/books?id=IsKThFbDkx4C&pg=PA70&lpg=PA70&dq=jewitt+spray+booth&source=bl&ots=d639h1xjtF&sig=Jhy7QNZVM7CHnAV74KtpvrqPkBU&hl=en&ei=RoPqSqvMIoK6swOC4r3nCA&sa=X&oi=book_result&ct=result&resnum=3&ved=0CB0Q6AEwAg#v=onepage&q=jewitt%20spray%20booth&f=false

[Brian Backner]

Jason,

If you have a commercial cabinet shop, the restrictions on what you can and can't do can be rather harsh. Even if you only use non-flammable finishes, I think OSHA will mandate an explosion proof fan. With a budget of 5K, I would suggest checking the market for used automobile spray painting booths - these are typically 8 or 12' wide by 20-24' long, but you can remove side panels to shorten them. And yes, they come with explosion proof fans. You can check your local CraigsList as a place to start in addition to Googling for manufacturers' info and specs. New these things go as expensive as you want, but I see them locally used for $2-10k depending on size/features (infrared heat to cure finishes, etc.).

Also, be aware that commercial installations require some research to set up properly. For instance, I know around here (Massachusetts) there is a requirement that spray booths have fire/smoke detectors that are set up to automatically alert the local fire station - you may want to check local regs as YMMV. A false alarm will still send out a truck/crew and you will pay for the cost ($2-3K a pop). No charge for a real fire, however.

Additional to the exhaust filters usually required to protect your neighbors, I would also consider intake filters - after all, you wouldn't want that 5,000+ cfm fan sucking airborne dust/bugs/etc. onto freshly laid on finish as it's sucking away the fumes.

Brian

[Matt Meiser]

You probably want to anonymously check with your state's environmental agency too, especially in CA.

[David G Baker]

My sons wanted to paint cars in their shop in California and were required to have a halon fire suppression setup at the cost of around $50,000 as well as a lot of other restrictions. Needless to say, that idea went out the window real fast.

[Al Navas]

Im planning to build a spray booth separate from my shop. Any suggestions for size and ventilation will be appreciated. thanks

jason
Jason,

You will some info here on SMC on how I built mine, at this link (http://sawmillcreek.org/showthread.php?t=56793&highlight=spray+booth), and also at this one (http://www.sawmillcreek.org/showthread.php?t=40466&highlight=spray+velcro). I spray *only* waterborne coatings, as I did not want to deal with the requirements of spraying with the solvent-based coatings.

I *still* used an explosion-proof exhaust blower from Grainger. It is 2,200 CFM, which exchanges one full volume of the air in my 12' X 15' finishing room. I exhaust to the outside, which means make-up air through filters in the wall.

One of the photos:

http://i4.photobucket.com/albums/y136/Sandal_Woods/Shop%20Tools/Finishingroom-spraybooth-1.jpg


.

[Brian Backner]

Al,

While you can get away with virtually anything in a home shop, putting a booth into a commercial shop kicks in local, state and even federal regs. Choosing to "only" spray waterborne finishes doesn't matter - who's to say one of your employees won't come in at night to touch up his mother's thingamajig, use lacquer and send your shop to the moon? What happens if you then go to sell your shop, etc., etc.

That's why OSHA and state regs all require that all commercial shops have explosion-proof everything and at such ridiculous costs (looks into the regs/costs of using two part polyurethanes if you want to be shocked/surprised).

Brian

[Wayne Cannon]

Sorry, I must have been tired and overlooked the fact that you were a commercial venture.