Parts Spray Booth/Fume Hood

[e-tek]

In another thread, someone asked about building a spray "booth" for small parts and just so happens I just built one, so I thought I'd share mine here rather than hijacking. I had thought of building one every time I sprayed some parts on my bench, or on the floor and had overspray all over, dust in my paint and the mist filled the shop for hours.
At first I was thinking of making it of sheet metal, or getting a furnace box - which would look best and be most "professional". But then I thought how I wanted to heat it hotter than the shop. I had some left-over ridgid foam insulation from the shop build, which turned out to be a perfect solution for me and free (best price!). As well, I can replace it when it gets too dirty.
On top, I cut a hole and inserted a furnace duct "amplifier" fan. These are used in long ducts to get the hot air all the way to the end of the run. They sell at Princess Auto (Harbour Freight?) for about $25.00 on sale. On top of that I just used the box it came in and covered one end with Allergen Furnace Filter material, which is catching all the organic vapours. I also installed a small heater and thermostat, so now I can paint and cure at higher temps!
Inside the cabinet, I can hang parts from the foam itself, or from hooks or hangars. Have a look, let me know what you think!

[Torque1st]

Nice use of available materials! It looks good.

[rickairmedic]

e-tec my only fear would be that that fan is not explosion proof and could ignite the paint fumes/overspray.

Rick

[e-tek]

Originally Posted by rickairmedic

e-tec my only fear would be that that fan is not explosion proof and could ignite the paint fumes/overspray.

Rick

Safety is over rated!!

Just kidding - great comment. I store all my thinners and paints right under that!
Wonder if that's true of the heater too - guess it would be. Can you buy explosion-proof heaters? I'll have to see if there's a different fan I could use. The beauty of this one is that it pulled a lot of air, but was very gentle - no pushback.

[rickairmedic]

e-tec for the fan the answer might be putting the filter before the fan instead of past it . The heater is another issue altogether .


Rick

[PAToyota]

I'm sort of thinking that the heater, fan, explosive vapors, and fairly flammable foam insulation board is not exactly OSHA approved. I'm also thinking that the filter fabric is not doing anything for organic vapors - you'd need a charcoal filter of some sort for that.

Bare minimum I'd make the enclosure out of plywood and run the duct outside of the shop. For his model railroading, for decades my father has used a plywood enclosure with a kitchen range hood as an exhaust without issues.

[kbs2244]

I would have a concern about the motor being in air flow and having fumes going over it also.
The cheap trick around that is to use a blower assembly from a junk cloths dryer.
Because they are afraid of the lint catching fire, the blowers have the motor outside the air flow.
They move lots of air, they are free at the curb, and the come with about 3 feet of 4 inch ductwork to get you started
When you take it out of the dryer, be sure to get the wireing digram for the machine.
They put all kinds of safty interlocks around them, and they will interupt both side of the circuit.
On this one I ended up tieing 2 wires together on both the hot and ground sides before wireing it to a plug in cord.
It wasn't hard, but I couldn't have done it without the digram since everything changes colors all through the machine.
(BTW Starting ether will work really well on the advisive holding the wireing diagram to the box.)
You will need a foot plate across the bottom with a 3 or 4 inch hole centered on the blower shaft.
These things will typicaly be filthy with dust and lint when you take them out.
This one has been gone over with a blow gun more than once.

[kbs2244]

As far as the box is concerned, if this is going to be one of those "temp to perm" tools,
I would guess some imaginative use of hinges could give you a fold up box that will store easier.
Check out some of the furniture design sites.

[e-tek]

Hmmmm - I thought it was too good to be "OSHA Compliant"!!! Damn!

Oh well, I'm calling it my PROTOTYPE now.... Great ideas on making this idea better/safer. I like the kitchen fume hood idea, but maybe I'll go with my original idea of finding a sheet metal box of the same size, putting a dryer motor or kitchen hood on it and vent it outside. I was going to do that, but didn't want to cut a hole in the new shop and the siding until I was sure where it should go, etc. Maybe charcoal is the best answer there.

As usual, thanks guys! Any more ideas/improvements?

[kbs2244]

I didn't think of it, but the kitchen vent blowers should have remote motors also.
They don't want any grease fires blamed on them.

[billspit]

Originally Posted by kbs2244

I didn't think of it, but the kitchen vent blowers should have remote motors also.
They don't want any grease fires blamed on them.

Now that you mentioned that, you could get an old cast off vent hood and put side walls and a back on it. Presto changeo, a spray booth.

Guess who through a perfectly good one away a couple of years ago?

[Industrial Concepts]

Originally Posted by rickairmedic

e-tec for the fan the answer might be putting the filter before the fan instead of past it . The heater is another issue altogether .


Rick

Rick/etec

Filters are only for particulate not fumes/ vocs. This fan is a big no no. There is no need for an explosion proof motor, the motor can't be in the air stream. NFPA 33 states when using a spray booth all electrical connections must be 5ft from the opening of the spray zone. Control panels 3ft away from a door. Most industrial spray booths utilize a tube axial fan with a non explosion proof motor.

[KenS]

Originally Posted by Industrial Concepts

a non explosion proof motor.

HHHmmmmm...

Sounds like it's ready to blow at any minute.

[buening]

I'm going to build my box using funace filters. No fans needed assuming you aren't painting for 10 minutes (small parts box, so not likely) and the filters are replaceable

[e-tek]

Originally Posted by buening

I'm going to build my box using funace filters. No fans needed assuming you aren't painting for 10 minutes (small parts box, so not likely) and the filters are replaceable

The reason I put a fan in was that I had painted in a box before. What I found was that it can cloud up and you can't see all that well (depending on the size of the part!) and it's nice to have the fumes going through this fan and through the filter.

To all - the safety changes will be nice, BUT - it's not as though this model doesn't work - IT WORKS EXTREMELY WELL for what I wanted. It contains the fumes and overspray. The fan removes the spray from my work area AND it stops the overspray from floating out and onto everything around. Whether or not it's the safest, or VOC's are being trapped or not, the overspray is caught & the smell is now non-existant. I have used it for about 10 parts thus far (you can see some of them in there). The extra heat is awesome, as my shop is generally 12-15C (56-64F) and having the paint box at 75-80F makes the paint flow better and dry faster!

Upgrades will be made - stay tuned!

[PAToyota]

Originally Posted by buening

I'm going to build my box using funace filters.

Again, furnace filters aren't going to do anything for the fumes - perhaps catch the overspray, but that is about it.

[buening]

Originally Posted by PAToyota

Again, furnace filters aren't going to do anything for the fumes - perhaps catch the overspray, but that is about it.

Fumes don't bother me as I can simply open the garage door. Overspray on my walls/floors/cabinets do, and I learned my lesson once.

[e-tek]

Originally Posted by PAToyota

Again, furnace filters aren't going to do anything for the fumes - perhaps catch the overspray, but that is about it.

PAT - I hear ya, but when I doubled up a microfibre allergen filter, which even cathces cigarette smoke - I can't smell any of the overspray, whereas I could prior. So even if it's not getting all the VOC's, it is getting what was bothering me and as such I'll probably use it unitl I vent it outside. As I said, I don't really want to cut another hole in my new walls!
Perhaps if I set it up under my exhaust fan that would solve my problem, as the exhausted portion would go right outside without any new holes.

[spike95]

Originally Posted by billspit

Now that you mentioned that, you could get an old cast off vent hood and put side walls and a back on it. Presto changeo, a spray booth.

Guess who through a perfectly good one away a couple of years ago?

This is making me sick. I threw away a good vent hood just a couple weeks ago.
I have been thinking about making a small booth for a long time and would now have the space to do it, but using the hood never crossed my mind. Don't I feel dumb.

[Uncle Buck]

I think you would be better served by simply skipping the whole enclosure thing and using tarps, or the like to cover what you do not want painted and spray over an old piece of plywood and the like, keeping the whole area ventilated. This is my answer for rattle cans, which judging from the pics is what you are using.

You can get heaters, fans, switches and lighting made for explosion proof environments, but be prepared. Explosion proof anything comes at great cost $$$$$$$$$$$ huge increase in cost, not really justified for most do it yourselfers, and certainly not justified for rattlecan painting. My 2 bits (great thought though!)