Cheapskate Spray Booth

When I put my electric kiln in the basement, discovered that it put out enough fumes to give me a headache when firing. So a kiln vent was in order. I decided the commercial units were too expensive for what they are made from so I opted to build my own. The little 4" duct fan I purchased didn't develop enough suction to reverse the bottom to top heat flow in my kiln.

So I got a powerful Vortek 4" fan that has excess drawing power.

That could have been the end of the story, but when I saw what Steven Hill was doing by spraying glazes, I knew I had to have a spray booth. Again being the cheapskate that I am, I was horrified by the prices of spray booths. It occurred to me that if my booth had a small enough opening, I might be able to use my kiln vent fan to vent the spray booth. I was thinking of building the box out of wood, but decided to look for alternatives. Steven's booth was built from a fiberglas shower stall. Off I went to Home Depot in search of the perfect spray booth. I ended up getting the biggest Rubbermaid plastic storage box I could find.

I cut out one end of it and cut a 4" hole in the other end, and added a 4" duct adaptor. I just sit the thing upside down on top of my kiln an connect it to my vent and it makes a serviceable spray booth. I buy cheap furnace filters, cut them in half and layer 3 of them in front of the exhaust to trap as much glaze overspray as possible.

My setup is a little small but quite useable. It captures most of the overspray, except when spraying a hollow form like the inside of a bowl that sends the spray back at me with enough velocity to overcome the fan's draw, but I wear a respirator when spraying, so it's not that big a problem. I've done three spraying sessions and am pretty happy with my setup. -George Lewter-

Update Feb. 8, 2112

What I have allows me to spray glazes and contain almost all of the overspray. I go through a fair amount of furnace filters and the glaze in the filters is wasted.

800-1,000 cfm is the recommended air movement for spray booths.  Mine is only 160 cfm, serviceable, but not a strong intake - go higher if possible with 6-8" vent piping. Its what I had already in use for my kiln vent.  More air movement is better.

I plan to replace the plastic box with the tub from an old dishwasher for better size and easier cleaning. The bottom half of a broken 36" fiberglass shower is also a good choice. Plumbing supply places frequently have them that have been damaged in shipment. The air outlet will be at the top. It will also work better if I get around to a water bath system which would spray water down the walls and into a reservoir with a recirculating pump. The glaze would settle to the bottom and clearer water nearer the top would be drawn up to again for spraying down the walls. This would capture most overspray and keep the  used glaze for recycling into scrap glaze.

Comment

You need to be a member of Electric Cone 6 & Other Ways w/ Clay to add comments!

Join Electric Cone 6 & Other Ways w/ Clay

Comment by Kathy Ransom on December 14, 2010 at 1:59pm

Thank you very much for the info George.  I hope to have my kiln set up and commence firing very soon!

Comment by Robert Seele on December 13, 2010 at 3:17pm

Here is a link for another home made spray booth.

 

http://picasaweb.google.com/AviHarriman/SprayBooth#

Comment by susan claysmith on December 7, 2010 at 9:04pm
Hi George - I agree that the shop vac will probably be inadequate. I do like your blower system setup and I think that I will check into something with more power when I set up my system. How often do yo need to change your filters? Have you tried washable filters? susan
Comment by George Lewter on December 7, 2010 at 8:41pm
Susan and Kathy.
First to Susan -- Your shop vac will be better than no vent at all, but that high velocity air moving into the hose is many time faster than what you will get at the large front opening of your laundry tub. I think you will experience a lot of blow back of overspray that will escape the spray booth. Professional grade spray booths move in the vicinity of 1000 cu ft per minute, mine probably moves 150 and I get a bit of blow back off some shapes. I think you will have even more. If you already have the shop vac go ahead and try it. The worst that can happen is it won't draw enough volume to be effective, in which case you will need to go to a bigger fan and larger vent piping. Make sure you wear a dust and mists rated respirator when spraying. If your getting a lot of blow back you will find glaze dust on the outside of your respirator, on you glasses if you wear them, and on your face after a spraying session. These are obvious signs that your spray booth isn't drawing in enough air.

Kathy, You need a galvanized steel box with flanges that you can screw with sheet metal screws to the bottom of your kiln. 99% of the air moving through your vent will be room temperature air that will rapidly mix with the 1% of 2000 degree air coming from inside your kiln. Except for the flange screwed to the kiln, none of the vent piping will be more than slightly warm to the touch. I have posted a much more complete description of my kiln vent on a separate web page I describe a shutter in the vent box that lets a lot of room air mix with the hot kiln air so it can easily be handled by standard furnace and air conditioning vent piping.
Comment by Kathy Ransom on December 7, 2010 at 7:29pm
I have been trying to put together a down draft vent for a while but when I go to home depot and tell the salesmen what I want to build and the temp the kiln will reach I always get "you can't do that!" I have an in-line fan but my biggest problem is the collector box and a spring mechanism to hold the box tight to the bottom of the kiln. The boxes I've found are either PVC or aluminum and need to be glued together but I'm not sure if either will hold/melt. Can you tell me what you use to hold the box against the bottom of the kiln when it contracts during firing George?
Comment by susan claysmith on December 3, 2010 at 6:03pm
I have been thinking about building a spray booth. I like what you've done here. I was thinking that I would get a single plastic laundry tub and put it on edge and running a wet/dry shop vac off of the drain, which could be exhausted outside. I think that your venting and filtrarion system is a better way to go, although I think the laundrry tub might be a good way to go for the hood because of the size. I would enlarge the drain area to fit 4 inch venting to it. Any thoughts on this idea?
Comment by Marv Kitshaw on October 8, 2010 at 4:49am
I think we could also learn a lot from space saving for this too!
Comment by JUDITH FREDERICK on July 25, 2010 at 9:49pm
I am interested in you kiln vent, would you care to share a little more about that. I would appreciate it.
Comment by Judy Thompson on July 6, 2010 at 11:49pm
I am going to have my S.O. to look at this. What a great idea!
Comment by George Lewter on January 3, 2010 at 3:17pm
I would not use a speed controller. They are quite twitchy about maintaining a constant speed over time. The cycling of the A/C power voltage curve helps a motor keep a constant speed. I wouldn't buy the Vortek fan at this point unless you want to do the kiln vent/spray booth combo. I think by dampering the holes at the "cup", you will solve your venting issue. $115 sounds like about what I paid for the vortek fan. I don't really have to, but I usually open a small basement ventilating window for make up air the kiln keeps the basement pretty toasty, so I'm not pulling cold air into the house somewhere else where I don't really want it coming in.
Comment by George Lewter on January 3, 2010 at 1:54pm
Good questions. On my overpowered fan system I have a single 3/8" hole in the lid of the kiln and four 1/4" holes in a 6" square pattern at the bottom that fit inside a sheetmetal box with a four inch duct adaptor at the back and an adjustable shutter at the front. I quickly discovered that the shutter could not open far enough to reduce the suction to the point that hot air was coming out of the top of the kiln. As my kiln consistently fired cooler at the top, I concluded that I was pulling in too much air via the kiln vent, so I opened another shuttered opening in the 4" duct line between the kiln and the fan, and by adjusting the air there, I was able to finely control the exhaust/suction at the top of the kiln. I found the same situation you described -- a suction setting that is just barely pulling air at the top at low temperatures at the beginning of the firing cycle is not strong enough at high temperatures to maintain the top to bottom air flow. Your idea of closing off holes at the bottom is the right one, but you need to do it in a way that is adjustable, so you can change it during the firing and as the fan ages and loses some of its efficiency.
Comment by eleanor akowitz on December 24, 2009 at 4:49pm
wow! that is neat and cheap. my only concern is overspray on my kiln sides and on the walls by the kiln. is suppose i could do this by buying a vortex fan and adapting it to a home depot box. and move it away from the kiln . great idea!
thanks

Photos

Loading…
  • Add Photos
  • View All

Use These Links to Support Us

Purchase Glazes Cone 6 by Michael Bailey, The Potters Book of Glaze Recipes by Emmanuel Cooper, or Making Marks by Robin Hopper, all available at amazon.comMastering Cone 6 Glazes by John Hesselberth & Ron Roy is now out of print.

Harbor Freight is a great place to find unbeatable prices for better HVLP spray guns and serviceable economy models, as well as detail guns, all tested by our members for spraying glazes, as well as compressors to power the guns. As yet no one has tested and commented on the remarkably inexpensive air brushes at harbor freight.

The critter siphon gun is a spray alternative that is well liked by some of our members, and is available at amazon.

Amazon is also a competitive source for photo light tents for shooting professional quality pictures of your work. They also have the EZ Cube brand favored by several of our members. You might also want to purchase the book Photographing Arts, Crafts and Collectibles . . .

Following are a few scales useful for potters:

Weighmax Top-class Stainless Steel 6KG 13LB Digital kitchen scale, ... $19.99

American Weigh Black Blade Digital Scale, 1000g X 0.1g $11.08 

For the non-digitally inclined the old standard Ohaus Triple Pro Mechanical Triple Beam Balance, 2610g x 0.1g, with Tare $169.00

And finally a low cost clone of the OHaus. The Adam Equipment TBB2610T Triple Beam Mechanical Balance With Tare Beam $99.62

Videos

  • Add Videos
  • View All

© 2014   Created by George Lewter.   Powered by

Badges  |  Report an Issue  |  Terms of Service