My home made spray booth/box.
Parts w/ cost:
Large box $8 wallmart, Small box $4 Walmart, Duct connector $7 Home Depot, 2 computer fans w/ 110v power supply $26 ( ebay ), flex duct tube $7 Home Depot. Total cost $52.
Here are the parts. You can see I traced out where the filer slot would be:
The 66 qt main box:
The small 6 qt air collector box:
Dryer duct quick connector:
Fans from Ebay. They came prewired, with power supply. They are brushless, ball bearing. I wanted somthing that would pull about 100cfm. I wanted a light air flow, so it would pull fumes and light paint dust, but not pull too much of the paint away from the project. These are 70cfm each. I guessed that with 140 total cfm minus the restriction from filter media and flow restriction in the exhuast collection box, I should still be at 100cfm.
Going to use the lid from the small box to attach vent hose to window. It fits perfectly:
Will continue in next post.
Holes that need to be cut for fans and exhaust. I left the center piece between fans for stability. I tried to use razor blades to cut this, that didnt work well. I ended up using an Electric Cutout Tool from harbor freight ( item#42831 ) with a name brand cutout bit. Bought this a few years ago on sale for $10. This worked like a charm.
When placing the smaller box on the larger box, there was a gap between the box on the ends. I used 1/2" x 3/8" foam seal tape as seen here:
Then used small sheet metal screws in the corners to attach them together. Not pictured, I used silicon caulk to seal around the top and bottom edges and where there was a slight gap at the ends of the foam tape:
Then I hot glued a 3/4x3/4" piece of wood along the bottom to hold the filter in place. I pushed it back just enough so the filter was pushed up against the fans. I did this so I didnt have to box the filter in completely. With the media against the fans, it shouldn't pull any paint around the sides. I tested and the media doesn't hinder the fan blades:
Vent hose connector ( female ) attached to the small box with silicone to seal and hot glue to hold in place ( you can see the hot glue on the sides ). I cut a small hole in top for the fan wires to pass through ( then sealed with silicone ):
The complete assembly. To attach the other end of the vent tube, I cut a bunch of tabs in the end of the tube, pull the tube through the hole on the small box lid, then bent the tabs over. Then sealed with silicone:
With the filter media, front and side view:
As can be seen above, I attached the fans ( with bolt/nuts ) to the inside of the spray box. Originaly I was going to mount them on the outside, but that left little room in the collector box, between the fan and the back of the collector box. I was afraid that would create too much of a back flow and restrict the fan too much ( the fans are 1" wide ).
I choose these plastic tubs becuase they were sightly opaque. This allows lots of light to shine through. I am hoping i will need no more than maybe a small lamp up top for lighting.
Nice spray booth Jim, hope it works as good as it looks. Keep us posted on how it performs.
-Bob
Life is what happens while you are making other plans!
Thanx Bob. When I was looking, ebay had a nice portable booth for $80 ( now $70 ), but it was only 13" wide. I wanted something wider because I plan on ( one day ) building a large ship model ( Cutty Shark ).
What do you plan on applying in your paint booth? Water based acrylics? Flammable/combustible based paints? Spray paints (rattle can)?
Inspired by Addiction
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Very nice booth! Well thought out.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
PennCentral99 What do you plan on applying in your paint booth? Water based acrylics? Flammable/combustible based paints? Spray paints (rattle can)?
All of the above? Questioned as i dont really know. I'm considering an airbrush at the moment. Either way, if your concerned about the flammable gases and the fans, I choose brushless just in case.
Very nice work! One concern I have.......... Are those fan motors "sparkless" (for want of the proper word)? If you use oil based paints, the fine mist can ignite from the minute motor sparks. That would not be a pleasant surprise.
If you use non-oil based paints, this is a moot point.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
I would be interested in learning more about the electric fans and the flammable nature of some paints. Is there a risk of combusition and fire?
Rich
Alton Junction
richhotrain I would be interested in learning more about the electric fans and the flammable nature of some paints. Is there a risk of combusition and fire? Rich
The recipe for fire requires heat, fuel, oxygen and a chemical chain reaction. There's oxygen in the air we breathe. The heat (ignition) can come from several sources; in this case, it could be the light he plans on using, the fan motors or even static electricity (not sure if "brushless" classifies as "intrinsically" safe). The fuel would be the vapors from the flamm/comb liquid. The vapors would need to be in a proper ratio to burn (just like a carburetor on a motor - to rich or to lean won't burn correctly). All this brought together in the proper setting will result in your chemical chain reaction.
Would need to read the manufacturer data on the fans. Every paint can has a label, which would also need to be read for flammable or combustibility. The difference between flammable and combustible is the temperature a which it ignites. Just for a quick "down and dirty" - a liquid that ignites below 100 degree farenheit is flammable, above 100 would be combustible (think gasoline vs. diesel)
Thanks, PC, kinda scary.
OK, I'll be the "glass half empty guy" (somebody had to do it)
A few points:
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
I know of guys using cheap bathroom exhaust fans in a simular size spray box without problems ( so far ). Those fans have brushes which do spark. I am using a brushless which does not produce sparks. There are many who have used what I am using with good results. Can an explosion happen? I'm sure there is a slim chance somehow. But there is also the chance I could be killed in an auto accident while driving to a LHS. I'm not going to live in a bubble. If I burn my house down, I'll make sure to post it here.
My fans may not have enought CFM, I havent tried using it yet. If I have to go with more CFM, I will. If that turns out to be the case, I will look into a U.S.C.G. approved exhuast fan ( they can be had fairly cheap ).
carl425 OK, I'll be the "glass half empty guy" (somebody had to do it)
Just remember, the glass can always be refilled. :)
You'll need lights when the clear plastic gets covered with paint.
The plan is to try clear plastic wrap, clinging to side walls, but i am not sure that it will cling. If it does, then I just toss the cling wrap as it starts to get a paint build up. If that doesnt work ( cling ), I was thnking of applying a light coat of cooking oil, like a PAM cooking spray, onto the sides/top. Would need soapy rag to clean, but would be doable. I did plan on placing a small light on top of the box to shine down ( through the plastic ) if needed.
No offence intended Jim, it is your house. But since your original post is presented in the form of a tutorial, I felt anyone considering following your advice should be fully informed.
JimInMichiganCan an explosion happen? I'm sure there is a slim chance somehow. But there is also the chance I could be killed in an auto accident while driving to a LHS. I'm not going to live in a bubble. If I burn my house down, I'll make sure to post it here.
One last point that your response brings to mind is that if you do burn down your house using this device, you will probably have voided your home owners insurance and will be on your own to pay for it. As you point out, the risk is very low, but the cost is very high.
Carl, no offence taken. I thank you for trying to help and warn others. I guess I'm the guy who remembers riding in the back dash of a car, not wearing seatbelts ( which now I do ), climbing a tree without safety equipment, ect.
I've had this on my radar screen awhile and read this with interest. I do seem to remember that our old friend Jeffrey reported and episode with something like an old vent fan of some type. So if I try a homemeade type someday I will have to get more comfortable with the fire/explosion prevention aspects. I do recall some folks reporting on using squirrel cage blowers where the air flow does not surround the motor IIRC.
http://cs.trains.com/mrr/f/88/t/231327.aspx
One detail I noticed was the filter I think is a typical fiberglass A/C filter? I would imagine that would pass alot of paint mist as the spaces are fairly large between fibers and the indirect path is needed for particles to "hit" the fibers along the route. I wonder if some optimizing could be done with the finer pleated allergen filters I see in Lowes. It might be possible to select one with a better balance between airflow, particle pickup and filter longevity (and cost, if that important).
Paul
Modeling HO with a transition era UP bent
JimInMichigan PennCentral99 What do you plan on applying in your paint booth? Water based acrylics? Flammable/combustible based paints? Spray paints (rattle can)? All of the above? Questioned as i dont really know. I'm considering an airbrush at the moment. Either way, if your concerned about the flammable gases and the fans, I choose brushless just in case.
Another thought is that some oil based spray paints may contain chemical elements that might eat into the plastic box. This is probably a very low probability these days, and would be more of an annoyance than a fire hazard, but it's a possibility.
peahrens....One detail I noticed was the filter I think is a typical fiberglass A/C filter? I would imagine that would pass alot of paint mist as the spaces are fairly large between fibers and the indirect path is needed for particles to "hit" the fibers along the route. I wonder if some optimizing could be done with the finer pleated allergen filters....
I deliberately chose fibreglass filters because the paper ones would be clogged after one painting session. The fibreglass, perhaps surprisingly, doesn't allow all that much paint through, and my fan blades are relatively clean even after almost 35 years of airbrushing.If you have the fan running before you even start spraying, there's not much chance of fire or explosion, as the concentration of flammables never gets very high. You should, however, provide a source of make-up air to replenish that exhausted by the fan.
Wayne
Hi again!
As Wayne indicated, having the fan on before spraying will also keep the "sparking issue" down as it occurs more typically when the switch is turned on/off.
Given I've spent a lot of time at refineries and went thru fire training, etc., I am probably more sensitive to the issue than most. But the idea of a homemade spray booth is very tempting and if vented properly, a great thing to have.
Soooo, may I suggest this...... have a proper fire extinguisher near by - just in case. Actually, you should have one in your work room anyway.
SPRAY BOOTH of LION:
For the amount of spraying that I do, it is wholy sufficient.
1) LIION glue foam to wall with silicone caulk.
2) When Dry, LION glue box to wall with silicone caulk. Will not slip because of the foam, foam did not slip because is too light.
Project done.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
My experience with fiberglass filters is similar to Wayne's. After multiple uses of the booth (certainly not 35 years though) there is very little paint on the fan blades. The other indicator that the filters are stopping most of the paint is that they clog fairly quickly. The filter may look ok and the air flow is not totally blocked but the volume of air is reduced significantly. On one occasion I pulled the filter when the fan was still running. I was suprised by how much the fan sped up as soon as the filter was out of the way. The fan was obviously labouring because of the partially clogged filter. To me, overheating the fan represents more of a risk than sparking. Note that the filter did not seem to be heavily clogged to the eye. I could still see through it. I am using a standard 16" square three speed cooling fan.
This is what the filter looked like:
As far as fire risks go, I am using acrylics exclusively, and I don't run the fan when I'm cleaning the air brush with laquer thinner.
A $29 (with shipping) Bilge fan from Amazon will be safe and produce enough flow to get the particles to the filter. http://www.amazon.com/gp/product/B00D96LYSY/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A10KONGIV6WPUI
Have fun!
Dan
A very nicely done spray booth...I need to start thinking about some kind of portable booth for my workbench.
Bob Berger, C.O.O. N-ovation & Northwestern R.R. My patio layout....SEE IT HERE
There's no place like ~/ ;)
Update:
Sorry it has taken so long. The 70cfm fans ( 140 total ) were just a bit too weak. I just purchased a couple 140cfm muffin fans ( 280 total ) from the same supplier as the originals. Not installed yet, but wanted to type an update as to how the spray box has worked out.
In gerenal, it has worked great, other than I did notice a little of the fumes a couple times. Hense the reason for upgrading the fans. Lighting has not been an issue, the semi clear plastic is working great. I haven't used it heavily yet, so I have not worried about trying to keep the plastic clean.
A filter alone can build up quite a bit of static pressure and just gets worse as they get dirty. Those computer fans will just deadhead trying to draw air through a filter.
I wouldn't use those fans becuase they are not for paint exhaust. You need a squirrel cage fan to be safe because the air does not flow through the motor.
j...........
I ended up buying the fan from Walmart for $17; picked it up at the store.
240CFM and works great!