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AFV Painting & Weathering
Answers to questions about the right paint scheme or tips for the right effect.
DIY Spray Booth
ProfessorP
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Minnesota, United States
Joined: February 20, 2007
KitMaker: 339 posts
Armorama: 325 posts
Posted: Sunday, April 24, 2011 - 05:49 PM UTC
Here's my DIY hobby spray booth that I built last week for less than $60. I got the idea from similar designs I found while digging around on the interwebs and I just incorporated my own features to make it a little nicer and more efficient. Thought I would post it here since I figured others might be interested in doing something similar.

Below is a parts list of components I got from Menard's and Target but most of which is probably available at Home Depot, Lowes or any other building center:

62 Liter Sterilite clear plastic storage tub (model 1758 available only at Target, chosen specifically for its very flat bottom and ability to accommodate a 14"x 20" filter, $9. However, just about any plastic storage tub would work for this if you mount the fan differently and use a different size/shape air filter.
General Electric 70CFM Bathroom Fan, Model BF85A ($20)
6 ft grounded power supply cord ($4)
Components to assemble a switch, housing and cover + wiring (about $5)
Flexible 3" vinyl dryer exhaust tubing and hose clamps (about $5)
Sheet of 1/8" plywood for window panel ($8)
Roll of foam Insulating tape ($4)
14" x 20" x 1" fiberglass furnace filter (58)
* Various and sundry screws, washers, wire nuts, etc. (free)

I started by cutting a hole in the bottom of the tub that's just large enough to fit the fan snugly. This will cut down on the work you will have to do to seal up the hole so that you get a good draw through the fan.



The fan itself is mounted between two foot-long pieces of two-by-four with wood screws, which in turn, are secured to the bottom of the tub with screws and washers.



I boxed in the outside of the fan with plywood just to make it look nicer and ostensibly to provide a bit more sound insulation, but of course that's totally optional.



Once the fan was securely mounted to the tub, I wired it to a standard on/off switch. Or, you could wire it directly to the power cord if you just want to plug it in only when you need it. I've since toyed with the idea of replacing the on/off switch with a timer switch so I can turn it on, spray my models and leave it running for 30 minutes or so, but haven't gotten around to looking into this.

IMPORTANT WORD OF CAUTION: If you don't know anything about electrical wiring, make sure you ask someone with electrical knowledge before trying to wire up an on/off switch! I plugged this thing in and blew my house's electrical main circuit (twice!) before I realized that my "simple" wiring scheme was not even close to correct. Please don't be a like me...make sure you know the RIGHT way to wire a switch so you don't set your house on fire...

As you can see in one of the photos above, I used foam insulating tape to seal up the inside of the tub where the fan fits into the hole. This also had the added benefit of sealing the gap where the fan cover meets the fan housing which created a bit more of a venturi effect so that the air is drawn straight through the fan cover and not in around the edges. I had enough insulating tape to create a sealed channel all the way around the inside of the tub into which the fiberglass filter fits. I mounted a small shaft/screw through the top of the tub to hold the filter in place...I just pull it up out of the way to allow for quick removal of the filter. This is needed because the filter is mounted at a pretty extreme angle to allow more room for models in the spray area. Without a pin, it won't stay in place when your are spraying.



To protect the fan itself from paint, I had planned to use a good quality paper furnace filter but I quickly discovered that the fan didn't pull enough air through it to draw the overspray into the tub. So I switched to a cheaper, "breezier" fiberglass type filter. It's just there to keep the largest paint particles out of the fan so I think it is working well enough. After a few uses, I'll check the fan cover for paint to see how much, if any, is actually getting through. As an aside, the type of fan employed here is a "sparkless" design where the electrical current simply activates an electromagnet ,which spins the fan. There is no electric "fan motor" per se, so there's no sparks and little if any danger of paint fumes igniting. My guess is that most household bathroom fans are of this design but it'd be a good idea to double check before you buy one if you can't find the specific GE model listed above.

Finally, for the window panel, I cut a piece of plywood just wide enough to fit into my window with a 4" hole in it to accommodate a standard dryer vent hood mounted on the outside of the panel.



The 3" exhaust tube connects to the 4" vent hood but I needed a 3" to 4" adapter for this ($2). You could probably just cut a 3" hole in the panel and hose clamp the tube on the other side if you don't care about backdraft when the fan is off. I also found out on the first use that it is essential to make sure you have a good seal all the way around the window panel where it meets the window frame and around the hole where the tube exits. This is so that the fumes don't sneak back in either around the edges or around the mounting hole for the tube.



Bonus: I happened to have an 18" florescent work lamp that I just lay onto the top of the tub to provide some direct lighting. Because it's on the outside of the tub, there's no chance of it getting paint overspray on it.



If needed, I can easily detach the hose and window panel, put them inside the tub, stick on the lid and store the whole thing in the closet between projects.

Hope you find this useful!

Cheers.
zontar
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Hawaii, United States
Joined: August 27, 2006
KitMaker: 1,626 posts
Armorama: 1,546 posts
Posted: Sunday, April 24, 2011 - 07:25 PM UTC
Super Cool! You've inspired me to complete mine as I purchased the fan and the light some time ago and then got distracted. Thanks for the great step by step and the materials list.

Happy Modelling, -zon
rebelsoldier
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Arizona, United States
Joined: June 30, 2004
KitMaker: 1,336 posts
Armorama: 757 posts
Posted: Saturday, April 30, 2011 - 08:35 AM UTC
thank you professor!
a great and informative piece and design!


reb

Krieg-Hammer
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Scotland, United Kingdom
Joined: May 17, 2011
KitMaker: 106 posts
Armorama: 92 posts
Posted: Tuesday, June 07, 2011 - 07:46 AM UTC
Yup you'll def need some electrical knowledge or get someone in the know. You don't want to cross over the live and neutral wires, and ensure it is the live wire that is being switched. You'll need to earth and cross bond (Ground) all metal on this homemade device, so if there is a breakdown in the wiring insulation or so, you will be protected by the consumer unit mccb if anything did go wrong.

A way to make it far safer would be to use a step down transformer (230V-12V UK/Europe) (120V-12V USA/Canada) and run the whole set up at 12V AC. The sizing of the transformer in watts will have to be calculated by the total wattage of the fan, light etc. I am sure us members on this forum could come up with a refined DIY base design.
Alaska
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Maine, United States
Joined: January 22, 2015
KitMaker: 158 posts
Armorama: 112 posts
Posted: Saturday, May 09, 2015 - 02:29 AM UTC
Hey Don..

Great post Don ! I've been thinking of purchasing a spray booth but the commercial versions cost are way out of sight for this modeler and so I have be running some ideas around in my head to build my own also and (Your) own creativity has helped me add to my own thoughts on the subject.

Thanks for posting your nice little project it's great!

Craig..
210cav
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Virginia, United States
Joined: February 05, 2002
KitMaker: 6,139 posts
Armorama: 4,563 posts
Posted: Saturday, May 09, 2015 - 04:20 AM UTC
Don-- great post! I am collecting the items to replicate your fine work
Many thanks
DJ
SSGToms
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Connecticut, United States
Joined: April 02, 2005
KitMaker: 3,511 posts
Armorama: 3,003 posts
Posted: Tuesday, May 12, 2015 - 09:59 PM UTC
Don,

This is such a well made booth, and economical. Your parts list and tutorial make it concise and complete. I am pinning it to the top of the painting forum for ready reference.
j76lr
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New Jersey, United States
Joined: September 22, 2006
KitMaker: 1,054 posts
Armorama: 1,039 posts
Posted: Friday, July 22, 2016 - 07:35 PM UTC
that's nice !! great job . I'm going to give that a try !! Thanks !
railbuilderdhd
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United States
Joined: February 23, 2009
KitMaker: 113 posts
Armorama: 91 posts
Posted: Monday, November 14, 2016 - 10:46 PM UTC
Looks great and I was thinking I would try this now but I can't find that fan or one that will work for less then $100+. Yuck!

Dave
doppelganger
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Idaho, United States
Joined: March 09, 2010
KitMaker: 557 posts
Armorama: 217 posts
Posted: Saturday, December 10, 2016 - 12:30 PM UTC
I have two inline duct fans on my booth,only $37.50, they work great and have mucho sucking power the windings are insulated however unless you use a motor that is not inline with the exhaust you run the risk of an explosion http://www.homedepot.com/p/Suncourt-Inductor-6-in-Corded-In-Line-Duct-Fan-DB206C/206584745?cm_mmc=Shopping%7cTHD%7cG%7c0%7cG-BASE-PLA-D26P-AirCirculation%7c&gclid=Cj0KEQiA7K7CBRCrwt26v5uHs98BEiQA0JzsZzwsikWyQKkIBXmcyIXlqhVuNUauhpstG25WYrVV5hYaAhkf8P8HAQ&gclsrc=aw.ds
Owengate
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United States
Joined: June 03, 2019
KitMaker: 73 posts
Armorama: 39 posts
Posted: Wednesday, June 26, 2019 - 03:52 AM UTC
It's innovative, indeed. I hope to have one of those in the future.
alanmac
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United Kingdom
Joined: February 25, 2007
KitMaker: 2,996 posts
Armorama: 2,917 posts
Posted: Wednesday, June 26, 2019 - 06:05 AM UTC
Hi

whilst this would have been relevant a few years ago, and the original post was 2011, given that you can now buy small folding spray units for around 60-70, that's about 70- 80 dollars is it really worth it?

After you've brought all the parts you must be pretty close that figure, without the hassle of making it or blowing the house fusebox....

A quick Google search brought up quite a few, all under different brands or unbranded but basically the same unit.



You can double them up for a bigger area, pack away when not in use and if brought from a reputable supplier, be able to get spares etc.