Sources for polyurethane/polyisocyanurate insulation board

donbingham · June 15, 2005, 05:12:31 PM

I want to use polyurethane insulation board for a DH Kiln but I am not able to find a source for the stuff. Since Home Depot and Lowe's came in and ran the local building supply stores out of business, I am pretty much stuck with what they have and they don't carry anthing but 1/2" board. They almost never have much in stock and what they have is busted up scrap. I thought it would be easy to find a source on the internet but when I did a Google search I found a lot of sites telling how good it was but no distributors. I could always get SIPs but they are not common around here and shipping would be way too much so I just want to find something like foil faced 1" or 2" insulation. I need some suggestions about where to look for this stuff.

Ernie · June 15, 2005, 06:30:55 PM

I used to have a polyisocyanurate spray gun set up which I used in my fiberglass business for insulating the holds of fishing boats.

You could try to see if there is someone in your area with a spray set up that way you could get it as thick or as thin as you want with no gaps.

Just remember that the fumes are super toxic and you need an external breathing outfit. I used a BA set like the firemen have.

Hope this helps.

Ernie

donbingham · June 16, 2005, 09:10:56 AM

I have thought about the spray set up and will probably use one if I cannot find the rigid sheets. I have a suppied air breathing set up that I bought for spraying polyurethane paints. I think the rigid foil faced sheets have better long term insulating properties so I would rather use them even though they would cost more.

Ernie · June 16, 2005, 02:35:37 PM

Don, I forgot. Welcome to the forum.

Ernie

Don_Lewis · June 16, 2005, 08:49:42 PM

Find out who does flat roofs (shopping centers, offices, motels etc.) and call them. They use it in thick sheets every day

Ironwood · June 16, 2005, 09:06:16 PM

Don Lewis,

Exactly! and they usually have "tapered" left overs that could be ripped on a band mill. I found some from a non profit used building material supply warehouse here in the "Burgh" (Pittsburgh). REID

Ernie · June 16, 2005, 09:53:11 PM

If ripping on a bandmill, don't breathe the dust, it's real nasty stuff

donbingham · June 17, 2005, 08:54:44 AM

The roofing lead is good. There should be a few of them in Austin. I had contacted a insulation materials supplier there but he said he did not stock it and I would have to order a semi load if I wanted it. There are also some surplus building supply stores there. I found a couple of sources for the spray urethane on the web. That stuff costs more than gold! Enough to put on 4" on a 12' x 20' building would cost $4200. I think I may need to look at less effective means of insulating my kiln. Since I am using a Lyle L200 DH unit and it was 100 degrees in the shade here yesterday, maybe I don't need all that much insulation.

Don_Lewis · June 18, 2005, 10:36:07 AM

Don't skimp on insulation. There are reasons to have it well insulated besides just heat loss. It is important to make sure that there are no or few points where the surface can be below the dewpoint and have condensation form. It is just as important to insulate in Guatemala as it is in Canada.

By the way, professionally applied spray foam is a very good way to insulate a kiln IF it is done right. There are ways it has to be applied that will work and ways that it won't. The spray kits that you buy are generally not good as the foam is too light for anything but patching. Most professional faom installers do not understand the quirks of kiln insulation. I can't tell you how many times I have had to argue with one of them to get them to do it right. I think they breath too much of that stuff, sometimes.

Dan_Shade · June 18, 2005, 07:26:02 PM

Don, I was under the impression that water condensing (when temp drops below the dew point, water condenses

) wasn't a problem in a solar kiln, and that it helped to avoid case hardening. Was this bum info?

I really don't know what's going on with the kiln I use. We did a relative humidity test/temp test last week, and it's dropping pretty good, but I have never bothered attempting to check the dew point, and I really don't know how, other than sticking my expensive Kestral unit in there. I'd rather not do that since I heard that the acids in the moisture can rot out the electronics.

to keep this on topic, I used the roll-type insulation, I figure it will eventually cause it all to rot out. the sheets of stuff were too expensive for my blood. Do you have any tips on the spray in methods? I'm planning on building another kiln when I get that far.