Paint booth fan?

[Leigh Betsch]

I am converting my downdraft sanding table to a duel purpose downdraft/paint booth. Basically I have a 3'x5' downdraft bench on wheels with an old furnace blower to draw the sanding dust thru the table and out thru furnace filters. With my sander hooked to my Festool dust extractor, it does a fine job. I plan to continue using this for sanding. But, I built a frame over the top of the bench to hang a clean room plastic curtain from and also enclosed the top, thus enclosing the bench. I rarely spray anything but water based finished these days however I think I should build it so I can also spray anything I might need. I would like to mount a separate fan for the paint booth purpose and just use the furnace blower for the sanding downdraft.
Does anyone know of a relatively cheap explosion proof fan for a paint booth?

[Leigh Betsch]

And LED lights, are they paint booth/explosion proof?

[Jim Becker]

I am converting my downdraft sanding table to a duel purpose downdraft/paint booth. Basically I have a 3'x5' downdraft bench on wheels with an old furnace blower to draw the sanding dust thru the table and out thru furnace filters. With my sander hooked to my Festool dust extractor, it does a fine job. I plan to continue using this for sanding. But, I built a frame over the top of the bench to hang a clean room plastic curtain from and also enclosed the top, thus enclosing the sides. I rarely spray anything but water based finished these days however I think I should build it so I can also spray anything I might need. I would like to mount a separate fan for the paint booth purpose and just use the furnace blower for the sanding downdraft.
Does anyone know of a relatively cheap explosion proof fan for a paint booth?

"Cheap" and "Explosion Proof" really have problems being in the same sentence... And I'm serious about that. Unless you believe you truly need to put in provisions for spraying solvent based products, it would be an expensive proposition to build out for that because in addition to the explosion proof fan and the necessary ducting outside (with the negative effect of spilling your heated/cooled air out with it) you'll need to make other safety provisions to isolate the space and do it correctly. With waterborne finishes, you're primary focus is capturing fines in the air from the spraying process which is much easier to deal with. While you still should wear PPE while spraying waterborne, it's primarily for particulates rather than chemical fumes at this point with modern waterborne products.

But if you really want an explosion proof fan, perhaps you can find something surplus rather than buying new.

There should be no issue with LED lighting...it's quite common. Just keep the switch on the outside of the space if you truly need "explosion proof".

[Leigh Betsch]

That's pretty much the same conclusion I have come to but I also thought maybe someone here has an option. I will surely want to do the occasional rattle can of something.
I have found paint booth fans on eBay for about $150 but I'm thinking they are counterfeit and probably not really explosion proof. I plan to just build a duct to mate up with a shop window.

"Cheap" and "Explosion Proof" really have problems being in the same sentence... And I'm serious about that. Unless you believe you truly need to put in provisions for spraying solvent based products, it would be an expensive proposition to build out for that because in addition to the explosion proof fan and the necessary ducting outside (with the negative effect of spilling your heated/cooled air out with it) you'll need to make other safety provisions to isolate the space and do it correctly. With waterborne finishes, you're primary focus is capturing fines in the air from the spraying process which is much easier to deal with. While you still should wear PPE while spraying waterborne, it's primarily for particulates rather than chemical fumes at this point with modern waterborne products.

But if you really want an explosion proof fan, perhaps you can find something surplus rather than buying new.

There should be no issue with LED lighting...it's quite common. Just keep the switch on the outside of the space if you truly need "explosion proof".

[Jim Becker]

I've taken to doing rattle can (solvent based) spraying outside which means avoiding it in the cold months, unfortunately. Even though I plan on a more thoughtful spraying environment in the new shop, it's most likely only going to be suitable for the waterborne stuff I largely spray and I'll just continue with the "outside" thing for rattle cans. But I'm aways from even having that on my radar and I could change my mind. There are some things I'd like to use with my guitar projects that most certainly are not waterborne...

[Rollie Meyers]

Most paint booth lighting is standard fixtures behind wired glass & are accessed from outside the booth.

[Jason Roehl]

If you only spray with an occasional rattle can, you’ll likely never come anywhere near the LEL of the solvent in your spray booth. You may not want to be in there due to the intensity of the fumes, but it takes a specific percentage range of the air to be solvent to even have a risk of an explosion.

[Bobby Robbinett]

We used to spray 100’s (if not more) of gallons of solvent based finishes at work using a primitive wall of the $89 red Harbor Freight exhaust fans. They actually did extremely good. We probably had 10 or more and they were cheap enough and readily available that we could swap one out here and there if one died. Those things last forever in an extremely harsh environment where we abused the crap out of them.

I would build you another down draft table with the furnace blower and just use that as a down draft booth. I am not sure if a furnace blower is explosion proof but I would give it a go or do some research.

I have worked in shops that have paint rooms with 16ft x 12ft walls of fans. My shop uses a down draft booth within an enclosed area. After my work pieces are sprayed they go to a separate room for drying. This is the most ideal way of doing it.

[Frank Pratt]

Haha, 'cheap explosion proof' are mutually exclusive concepts.

You can't use any kind of lighting that isn't approved the location, LED or not. But the work around is easy and one that is very commonly used. Just put a glass panel or two in the top of the booth and have whatever fixture you want sit on top. You do need to seal around the edges of the glass. There are also rules defining how far outside the opening of the booth is also classified as hazardous. I can't provide that for you because I only have the CEC and the NEC rules may vary a bit.

[Jeff Roltgen]

Hey fellow South Dakotan!

How long did it take for Steve Irwin to finally have the death he flirted with for decades?
I am scared sh@@tless that you may actually go forth with improper equipment* as described in another post above. Good for them. They accidentally did not have an accident. Your health, building, and life are simply not worth it. Please, disregard any advice to blissfully go forth doing what you know to be flirting with disaster, just because someone else got away with it.
Damned foolishness.

Just saw the largest commercial cab shop in our region go up in smoke last week. 24,000 square foot building. Opened for business at 7am. By 11:15 the alarm was raised. By 5pm: GONE. Pile of rubble still smoldering 24 hrs later.
No word yet, but chances are it was a finishing room disaster, yet again.

Good grief, people. Share good advice, but keep the daredevil stupidity to yourselves.

*BTW: 10 HF fans @ $89 = enough money to buy a Jenny explosion proof exhaust fan.

[Alan Lightstone]

In my last workshop I bought and installed an explosion proof fan. Moved it to my new workshop for the dedicated finishing room. Wouldn't think of spraying solvent based finishes without it. Nor should you.

Not cheap. Nor is the value of your life.

[Leigh Betsch]

A quick pic of the spray booth as it sets today. I’m still looking for a fan to mount to the back of it. The plan is to just exhaust out the shop window. I’ll make some kind of window sleeve once I get the fan figured out. I plan to make a cabinet into the front, and another one in the end. I installed two LED lights on the sides of the front opening. I have a few areas that need paint also. But for now I’m on hold while I do some work to dust collector. I filled the filters, damn.

[Frank Pratt]

A quick pic of the spray booth as it sets today. I’m still looking for a fan to mount to the back of it. The plan is to just exhaust out the shop window. I’ll make some kind of window sleeve once I get the fan figured out. I plan to make a cabinet into the front, and another one in the end. I installed two LED lights on the sides of the front opening. I have a few areas that need paint also. But for now I’m on hold while I do some work to dust collector. I filled the filters, damn.

You need to move those LED lights along with any associated wiring outside the box. The light can shine through the clear walls. It is not safe to have them inside the booth, LED or not. An added benefit is that the fixtures will not get fouled by overspray.

[Kevin Jenness]

If you are spraying solvent based finishes in any volume you need to decide what level of risk you are willing to take. What you can get away with and what is advisable may be two different things.
Best practice would call for 100 ft/min airflow across the booth area and any possible sparking sources outside the airstream.

I have a 24" tube-axial blower with a (undersized) 2' x 2' filter bank mounted in the wall of my shop. The blower is belt driven so the motor is outside the airflow. You might be able to find a similar unit used.

[Leigh Betsch]

Thanks for the 100 f/min number. It will help a bunch helping to pic a fan. I'd rather not over due it and create a noise monster. If I can't find something reasonably cheap ($150) I'll likely build something. The ebay axial fans I've been looking at are over 2675 cubic meters per hour, and 71db. Compared to the 100 cfm number they are way oversize.