Finally, I am in my NEW studio ! It is a mess of boxes, etc. for the time being. I am ripping out the carpeting around my kilns so they will sit on cement and I won't have a fire problem. I didn't think about the sheet rock walls behind the kilns until my electrician said that it's not safe - before I was in a basement with cement floors and walls so it was never an issue. He mentioned that I should buy interlocking bricks to build a wall behind the kilns and place them several inches from the sheet rock. Sounds good, but I was wondering what any of you have done if you have this situation. My ceilings in the studio are cathedral but come down lower were the kilns are because I have these banks of small windows that go in a horizontal direction along the top and then. He said I should put a heavy duty fan in one of the windows above the kiln. I also have a Casablanca ceiling fan that might not fair to will after countless firings. Any thoughts? I was thinking about just tacking up sheet metal to reflect the heat off of the ceiling. The rate I am going I won't be back in business full throtlle till next year ~Elle
It sounds like the electrictician was freaking out a bit, to me anyway. I would just put some Durock or wonder board up behind your kilns covering the drywall. But you should really check with your city inspectors to see if there is anything special you need to do to meet code.
I know there's discussion on this in the old archives. Seems to me someone posted that the sheet metal protection is not good because it conducts heat. That's what I happen to have behind the kilns, and it's not a problem unless I have a runaway kiln issue, as neither of mine radiate much heat on the surface. I believe many folks suggested cement backer board around the kilns.... that's probably less expensive than brick.
You didn't mention what kind of kiln you are running. I would measure the temp of the outside wall of the kiln at top temp, just to know what you are dealing with.
For a wood stove, the procedure is to make a wall with cement board like Hardibacker that is 1" offset from the drywall with a provision for air to flow from underneath and out the top. Wood stoves are designed to give off heat while kilns are designed to hold the heat in. You can use a number of creative ways to offset the cement board. My installers used copper tubing cut in 1" lengths. You are supposed to use a material that is less heat conducting than metal and also not flammable.
Yep, my electrician is very much a safety man and does go to extremes. He would probably feel that most of the houses in my town are wired wrong and could go up in smoke any second. he does have valid points though. There is a fireplace shop a few towns over that I will call this morning. They should be able to direct me to those cement boards. I will also try a contractor supply store to compare prices. I am assuming that this is something that I can put up by myself?
BTW, I run an 18" Paragon and a large Evenheat "coffin".
~Elle
Hi. I very seldom have anything to add to the board discussions but I do have a different approach to insulating the wall around your kiln. I went to a welding supply store and they sold me a welding blanket that tolerates temps up to 1000 degrees F. It is 4' X 8'. I drape it on the two cornor walls that suround my kiln. I can fold it back when I don't need it but I just leave it in place. I was so worried about burning my house down when I started, I got the highest rated one I could find ($100). After running my kiln I measured the outside temps and the highest it got was about 100 on a hot summer day. My utility room is small so I thought it would really heat up. If I had known the temp I would have gone with a lower rated blanket and paid less, but I feel really safe with what I have. Ann
I run an Evenheat coffin that is placed 12" away from a regular stud wall with a standard drywall finish. The heat outside this kiln at 12" is minimal.I think you don't need anything special if you keep a reasonable clearance.
The cement backer board can be purchased at places like Home Depot, it's not any particularly unusual material. Also, it's used to protect against worst case scenarios.... runaway kiln, in which case regular flammable materials are not good to have right next to your kiln. If I had my studio in my home or near it, I would most certainly take the extra precaution.
if you go the backer board route - do put in the spacer either with steel studs or metal clips. 1" should be fine. I learned the hard way that the airspace is critical! Install a fan that will exhaust to the outside.
I wouldn't rely on any active method (ie a fan) for keeping a wall cool, if the fan fails things would get hot. Do the backerboard thing like Bert said and keep the kiln the recommended distance from the wall.
Called a few places and found out that cement board is rather inexpensive - $13-$16 for a 3'x5' sheet. Figure that I need 2 of them. The welders blanket sounds intresting ! Fiber board with some brackets or bricks to give me air space should work out fine though. Unfortunatly, I can't test my kiln until I get the place rewired. My concern with the heat though is not how hot the kiln actually gets on the outside, but when I flash vent it to 1100 degrees. That's a whole lot of heat pouring out of that puppy!!!
I just want to get back on track It's driving me nuts! ~Elle
Why are you flash venting? This is REALLY hard on your bricks/fiber. About the only situation I would flash vent is when I would wnat to stop a slump in it's tracks, i.e. drop out. Besides the heat that actually reaches the ceiling isn't going to be hot enough to start anything on fire.
Interesting discussion. I'm just finishing builiding my studio so the following discussion pertains to AZ code but I suspect where you live it is not much different.
On fire code, I do not need any ventilation or sprinkler system as there is no open flame. Our kilns are not much different than a large Pizza oven and they do not require vents or sprinklers. For fire code I was required to have 5/8" sheetrock on the ceiling and walls. That is it. You can use backerboard if you want but I think you are going to a lot of expense unless you plan on placing the kilns closer to the walls than what is recommended by the manufacturer.
My kiln is a 4'x4'x1.5' steel cage with fiberboard/fiberblanket insulation. I've got a number of data-recording systems in place so when it is done I plan on taking a fair amount of data and I will make this data available to those on this board as there seems to be a large number of inquiries on this subject and no real data to back up any recommendations/suggestions.
Phil
PS - As an aside, I have a propane stove/fireplace in my home which is 1) open flame and 2) non-insulated. In fact it's sole function is to radiate heat not trap it. Placement of this is 12" from any wall and keep flamable material away. Mine does have a chimny but for lower elevations they do make units that do not. Granted, it's peak temp is not that of my kilns but its surface operating temp is far hotter than my kilns ever reach.
PPS - Ditto on Amy's comment, why are you flash venting??? Not required unless you are stopping a drop.
I am very interested to hear more on the topic of NOT flash venting, I understood it to be pretty important to avoid devit. My kiln is my laundry room and I would love to skip the flash venting. It's not too fun either! I guess too, a matter of time, my kiln loses heat pretty slowly and I imagine not flash venting would add hours to every fire. I'm very curious.
lissa wrote:I am very interested to hear more on the topic of NOT flash venting, I understood it to be pretty important to avoid devit. My kiln is my laundry room and I would love to skip the flash venting. It's not too fun either! I guess too, a matter of time, my kiln loses heat pretty slowly and I imagine not flash venting would add hours to every fire. I'm very curious.
lissa.
Flash venting has historically been used to avoid devit. The old (20 years ago) formulation of glasses devitted way worse than the newer formulas. Flash venting was used to get out of the devit range, above 1300F? as fast as possible. With the newer formulas, devit is not as much of a problem, and the ancillary wear and tear on lids is not desirable. There are many ways to avoid devit, but flash venting is the worst of them, in my opinion. Brock
My memory is so good, I can't remember the last time I forgot something . . .
Excellent! I use super spray usually, should I just program my kiln to drop AFAP to 1050 or so and let it do its thing? What a great thing to have learned today, thanks a bunch. I think our laundry room walls and ceiling will be quite pleased as well.
lissa wrote:I am very interested to hear more on the topic of NOT flash venting, I understood it to be pretty important to avoid devit. My kiln is my laundry room and I would love to skip the flash venting. It's not too fun either! I guess too, a matter of time, my kiln loses heat pretty slowly and I imagine not flash venting would add hours to every fire. I'm very curious.
lissa.
Flash venting has historically been used to avoid devit. The old (20 years ago) formulation of glasses devitted way worse than the newer formulas. Flash venting was used to get out of the devit range, above 1300F? as fast as possible. With the newer formulas, devit is not as much of a problem, and the ancillary wear and tear on lids is not desirable. There are many ways to avoid devit, but flash venting is the worst of them, in my opinion. Brock
One of the reasons I like fiber kilns is that once you stop adding heat, They cool down quickly. That is when you are above 1300º. I used to flash, then I discovered that I didn't need to, so I was happy to quit. In my kiln I can even get away with just stopping on a drop slump. With a brick kiln it might take some more foresight.
The float glasses I use will either devit or not. Flashing is not much of a deterrent. 10 mm and thicker don't devit anyway. 1/4" fired to below 1300 doesn't devit. So my only issues are thin glasses fired hot, and borax works for those.
Wow! I've been fusing for just about 5 years and used this board to get most of my information (What a Godsend!!!). Almost all of my pieces are pretty small - I make dichroic cabs for my jewelry - and I usually get away with using my 17" Paragon octagon kiln, since it would take forever to fill my coffin. The directions I was given early on was to fuse to about 1500 degrees, or whenever my pieces are how I want them, turn off and flash vent to 1100 degrees to stop the "cooking" process, and then shut the kiln until it reaches room temp. The reason I was told to flash vent was so that the cooling process will be shorter. I have never experienced diviet and really don't know what it is. (but if I did have something strange happen you can be sure I would hop on the board and ask I make ornaments in my large kiln (about 2.5-5" round) because I can put a whole run in there and it saves a heck of a lot of time. I just transferred the information I knew to that fusing process, hence, I flash vent. So now I really don't need to do that? It would save muscle power lifting up the lid and sometimes heating up my legs, and I would be thrilled!!!! I do still have to open the kiln to make sure the pieces are fused properly - tried the peephole thing and for the life of me can't figure out if things are fused to perfection or not. Because I do that I still have 1500 degrees escaping from the kiln, but for an instant. Might I be ok with just my sheet rock wall behind the kiln? I will have to unearth the instruction manual - it's in a box somewhere - and find out how far from the wall I need to have the kiln. If memory serves me right, I think it was 12".
Interested in hearing more about this "no flash venting".
I keep to just venting my unpacking frustrations for a while ~Elle
devit looks like a scummy surface. it can be gotten rid of by using a borax spray on the glass before fusing.
rig up some sort of pulley system to open your kiln, connected to the ceiling and wall behind the kiln. a 2 part pully will quarter the amount of force necessary to open the lid, and also let you be farther away from the heat.
! It is a mess of boxes, etc. for the time being. I am ripping out the carpeting around my kilns so they will sit on cement and I won't have a fire problem. I didn't think about the sheet rock walls behind the kilns until my electrician said that it's not safe - before I was in a basement with cement floors and walls so it was never an issue. He mentioned that I should buy interlocking bricks to build a wall behind the kilns and place them several inches from the sheet rock. Sounds good, but I was wondering what any of you have done if you have this situation. My ceilings in the studio are cathedral but come down lower were the kilns are because I have these banks of small windows that go in a horizontal direction along the top and then. He said I should put a heavy duty fan in one of the windows above the kiln. I also have a Casablanca ceiling fan that might not fair to will after countless firings. Any thoughts? I was thinking about just tacking up sheet metal to reflect the heat off of the ceiling. The rate I am going I won't be back in business full throtlle till next year 
~Elle
Install a fan that will exhaust to the outside.
I make ornaments in my large kiln (about 2.5-5" round) because I can put a whole run in there and it saves a heck of a lot of time. I just transferred the information I knew to that fusing process, hence, I flash vent. So now I really don't need to do that? It would save muscle power lifting up the lid and sometimes heating up my legs, and I would be thrilled!!!! I do still have to open the kiln to make sure the pieces are fused properly - tried the peephole thing and for the life of me can't figure out if things are fused to perfection or not. Because I do that I still have 1500 degrees escaping from the kiln, but for an instant. Might I be ok with just my sheet rock wall behind the kiln? I will have to unearth the instruction manual - it's in a box somewhere 
- and find out how far from the wall I need to have the kiln. If memory serves me right, I think it was 12". 
~Elle