[Rapid Dog]

I'm going to put 1/2" SuperWool 607 HT to the outside of my gas kiln to help with insulation. The kiln is only one softbrick deep (4 1/2").

Even tough this product is described as 'safe", I want to contain the fiber as best as possible. A friend suggested something calles "M-board" which I can't seem to source.

Otherwise, I'm planning to secure the blanket to sheet metaland rivet it closed around the outer walls to the frame.

Any input as to where I can find insulating board?
Suggestions on other materials?
Anything available at Home Depot maybe, like fireplace insulation board?

[Seasoned Warrior]

Rapid Dog, on 11 August 2010 - 09:38 AM, said:

I'm going to put 1/2" SuperWool 607 HT to the outside of my gas kiln to help with insulation. The kiln is only one softbrick deep (4 1/2").

Even tough this product is described as 'safe", I want to contain the fiber as best as possible. A friend suggested something calles "M-board" which I can't seem to source.

Otherwise, I'm planning to secure the blanket to sheet metaland rivet it closed around the outer walls to the frame.

Any input as to where I can find insulating board?
Suggestions on other materials?
Anything available at Home Depot maybe, like fireplace insulation board?

I have no idea where you are located but I would start with a place that specializes in refractory materials. I use an excellent one in Richmond, CA but you porbably have one close to you in a major urban area, especially if you have a lot of industry locally. I'm not aware of a specific material called "M" board but then there is a lot of jagon in many areas of business and it may be specific to your area or to a trade. Check your Yellow Pages or the Thomas Register.

Regards,
Charles

[Rapid Dog]

I'm in SoCal, north L.A. County.
I did a lot of searching yesterday, acan't even seem to find fire resistant board.
I think I'm just going with galvanized sheet and rivit it to the frame....

[KathyG]

I'm planning to use Hardibacker 1/2" underlay board as my outside panels, then kaowool panels, then soft firebrick as I build my gas kiln. I was just looking at the Hardie board website, and it seems that it should work well, but has anyone else used this? There isn't a direct rating for heat that I can find on the site.

Kathy

[Marcia Selsor]

KathyG, on 12 August 2010 - 02:39 PM, said:

I'm planning to use Hardibacker 1/2" underlay board as my outside panels, then kaowool panels, then soft firebrick as I build my gas kiln. I was just looking at the Hardie board website, and it seems that it should work well, but has anyone else used this? There isn't a direct rating for heat that I can find on the site.

Kathy

Hardibacker is concrete and water absorbent. I would keep it dry so the steam won't cause trouble, like popping or explosions.
Insblock insulation is a product name for a fiber refractory board. This would serve your purposes better, in my opinion.
Marcia

[KathyG]

Marcia Selsor, on 12 August 2010 - 04:03 PM, said:

KathyG, on 12 August 2010 - 02:39 PM, said:

I'm planning to use Hardibacker 1/2" underlay board as my outside panels, then kaowool panels, then soft firebrick as I build my gas kiln. I was just looking at the Hardie board website, and it seems that it should work well, but has anyone else used this? There isn't a direct rating for heat that I can find on the site.

Kathy

Hardibacker is concrete and water absorbent. I would keep it dry so the steam won't cause trouble, like popping or explosions.
Insblock insulation is a product name for a fiber refractory board. This would serve your purposes better, in my opinion.
Marcia

Hmm, I hadn't thought about any moisture problems. My main concern was whether it held its integrity after repeated exposure to high temperatures; cellulose makes up 10% of its composition. I found a good description of Insblock at Marc Ward's site http://www.wardburne...erproducts.html and am now leaning toward using sheet metal as my outer shell and increasing the Kaowool thickness from 1/2" to 1", as long as it can be compressed. I'm rebuilding a kiln that I took apart to move, so I have 3/4" of shell space between the frame and the bricks. The old shell didn't handle being taken apart too well.

Thanks for your input!

Kathy

[Rapid Dog]

I'm going to go with 1/2" Superwool on the outside with a galvanized sheet to contain it.
It should compress fairly well as I'll use self-drilling screws to secure to the kiln frame.
I think that should be sufficient. I don't think I really need the 1" wool because it reflects the heat inward anyway.
I intend to use some sodium silicate to seal anywhere that the wool is exposed.
Even though my kiln is outdoors (as is the studio) and the Superwool is claimed as 'safe" I don't want fiber blowing around.

[AmeriSwede]

KathyG, on 13 August 2010 - 02:57 AM, said:

Hmm, I hadn't thought about any moisture problems. My main concern was whether it held its integrity after repeated exposure to high temperatures; cellulose makes up 10% of its composition. I found a good description of Insblock at Marc Ward's site http://www.wardburne...erproducts.html and am now leaning toward using sheet metal as my outer shell and increasing the Kaowool thickness from 1/2" to 1", as long as it can be compressed. I'm rebuilding a kiln that I took apart to move, so I have 3/4" of shell space between the frame and the bricks. The old shell didn't handle being taken apart too well.

Thanks for your input!

Kathy

Kathy... I'm not quite sure what your meaning is when you say 'increasing the Kaowool thickness from 1/2" to 1", as long as it can be compressed.' Kaowool like any other insulating product yields its efficiency in insulating properties when uncompressed. When compressed these properties are diminished.

So if you are increasing your Kaowool blanket thickness, say, from 1/2" to 1" and then compressing back to 1/2" you would not be achieving much, if any, gain in insulation....In reality, you might be 'padding' the billfold of the supplier more than that of your kiln....

[JBaymore]

AmeriSwede, on 14 August 2010 - 02:01 AM, said:

Kaowool like any other insulating product yields its efficiency in insulating properties when uncompressed. When compressed these properties are diminished.

What he said.

best,

.................john

[KathyG]

JBaymore, on 14 August 2010 - 06:08 AM, said:

AmeriSwede, on 14 August 2010 - 02:01 AM, said:

Kaowool like any other insulating product yields its efficiency in insulating properties when uncompressed. When compressed these properties are diminished.

What he said.

best,

.................john

Point taken, thanks! I may end up with a little airspace, but I'm not sure since I'll be mortaring the bricks together this time. Will having a bit of space between the bricks, the kaowool and the sheet metal be any problem?

Kathy

[KathyG]

Rapid Dog, on 13 August 2010 - 07:08 AM, said:

I'm going to go with 1/2" Superwool on the outside with a galvanized sheet to contain it.
It should compress fairly well as I'll use self-drilling screws to secure to the kiln frame.
I think that should be sufficient. I don't think I really need the 1" wool because it reflects the heat inward anyway.
I intend to use some sodium silicate to seal anywhere that the wool is exposed.
Even though my kiln is outdoors (as is the studio) and the Superwool is claimed as 'safe" I don't want fiber blowing around.

We were just looking at the kiln parts, and the back with the flue is made of galvanized sheet. The kiln was built in the early 80s and kept outdoors with a small corrugated metal roof in a moist environment. The sheet metal looks to be in good shape, even at the screw holes, except for the flue. My husband thinks the flue had some heat leaks, because there is a rust pattern at its back in the shape of a fat candle flame. So, it looks to me like galvanized sheet covering good insulation should work well!

Kathy

[AmeriSwede]

KathyG, on 15 August 2010 - 01:07 AM, said:

Will having a bit of space between the bricks, the kaowool and the sheet metal be any problem?

Kathy

I really don't believe it would be a problem as the air space (sealed off) is an insulating element unto its own. However any future problems would most likely occur (in regards to that design aspect) if something was bumped up against the sheet metal exterior wall hard enough to move the bricks inward. It would not be advisable to move the kiln either, if it is built on wheels, unless done so with absolute care, so as not to jostle the exterior wall or knock the kaowool loose.

You might also care to check with your refractory supplier, they may sell Fiberfrax or some other insulation that would be suitable for the heat range with the thickness of the extra space you wish to fill. It will add to the cost but make the kiln more solid and could provide the (small) added benefit of extra fuel savings.

[AmeriSwede]

KathyG... after rereading your post, an addendum to my previous response above would be that it doesn't sound like it's that much extra space. The bricks will expand and contract naturally anyway as they go through the regular heat up and down cycles. One/quarter of an inch is not enough to personally bother me, but that is a call that you need to make. The Fiberfrax I mentioned, however, does come in about a quarter inch thickness so could easily be added for the fill you need. I don't think I personally would spend the money for that additional amount, as the space age insulation blankets and felt papers can be expensive.

[Marcia Selsor]

KathyG, on 14 August 2010 - 05:23 PM, said:

Rapid Dog, on 13 August 2010 - 07:08 AM, said:

I'm going to go with 1/2" Superwool on the outside with a galvanized sheet to contain it.
It should compress fairly well as I'll use self-drilling screws to secure to the kiln frame.
I think that should be sufficient. I don't think I really need the 1" wool because it reflects the heat inward anyway.
I intend to use some sodium silicate to seal anywhere that the wool is exposed.
Even though my kiln is outdoors (as is the studio) and the Superwool is claimed as 'safe" I don't want fiber blowing around.

We were just looking at the kiln parts, and the back with the flue is made of galvanized sheet. The kiln was built in the early 80s and kept outdoors with a small corrugated metal roof in a moist environment. The sheet metal looks to be in good shape, even at the screw holes, except for the flue. My husband thinks the flue had some heat leaks, because there is a rust pattern at its back in the shape of a fat candle flame. So, it looks to me like galvanized sheet covering good insulation should work well!

Kathy

Galvanized sheet metal contains zinc. Be careful of breathing the fumes if it gets hot enough to outgas.
Marcia

[KathyG]

Thanks for all of your input; I'm learning a lot!

Kathy