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Mark Dolan
12-10-2011, 09:51 AM
I bought a role of Ceramic Fiber to wrap around my Electric furnace to increase the heat retention. However, I have come to learn there are some health concerns with these fibers. Once I wrap this product around the furnace, is there something I can put over the fiber to reduce it's ability to go airborne?

Hugh Jenkins
12-10-2011, 12:25 PM
If you wrap it over a metal can, you will create a new hot face that will destroy the metal in time. That is a guarantee. Don't enclose metal.

If it is going to be the new exterior surface, there are "coating cements" that apply very nicely over almost any shape. I use some stuff called Super Stick 1900 but there are several other brands. It adds a heat leak preventing layer that is safe to touch, vacuums or sweeps clean, can be recoated for spring cleaning or open house. First coat can go on cold, and will shrink as it dries. Other layers will dry smoother and go best on a warm furnace. I highly recommend this stuff. There are also water proofing layers that can be put over it if that is necessary.

Pete saw what my furnace exterior looks like and called me a Gaudi wannabe.

Pete VanderLaan
12-10-2011, 01:59 PM
Is that what I said? I thought it to be pontilistic in nature and really more reminiscent of some early Monet. Gaudi? In your dreams. Grandma Prisbee perhaps.

But Hugh isn't kidding about not putting the fiber over sheet metal. Don't do it.

Hugh Jenkins
12-11-2011, 07:03 PM
Pete, I am crushed. I have lived with the glow of your comments since your visit and now I find out you not only don't remember, but would not say that again anyway.

I also have a correction to make. The material I use to coat fiber layers is an insulating cement. The coating cement is a very hard final coat that I do not use but can be used as a water barrier.

Cecil McKenzie
12-11-2011, 08:32 PM
The frax insulation I use on the top of my furnace is covered with aluminum foil with a few weights placed to keep it from blowing around. My furnace is outside.

I added a simple heat exchanger a few years ago. It is wrapped with frax then heavy aluminum foil, then 1/4 inch hardware cloth over the aluminum foil. Seems to work well and is not hard to remove if necessary.

George Tessman
12-11-2011, 09:56 PM
I have used sairset. thin it out spread over the fiber. It will dry to a hard shell.
Inside my glory hole I thin out ramable to a milkshake state and do the same.

Rick Sherbert
12-21-2011, 06:34 AM
Dip Lag ("rewettable cloth" is another name) is one thing to encapsulate fibers. Coloidal silica and zircon mixed will do the same (more expensive though).

Pete VanderLaan
12-21-2011, 09:33 AM
The material I use to coat fiber layers is an insulating cement. The coating cement is a very hard final coat that I do not use but can be used as a water barrier.

*************
The first truly certifiable ocean going furnace on the big Island but the barnacles near the cleanout slow it down in a following sea.

Hugh Jenkins
12-21-2011, 02:05 PM
I will run it against anyone in a fuel efficiency contest. Any takers? Beauty contest, no thanks!

Kenny Pieper
12-21-2011, 03:25 PM
Dip Lag ("rewettable cloth" is another name) is one thing to encapsulate fibers.

has anyone tried to re wet this stuff and use it again?

Thomas Chapman
12-21-2011, 05:33 PM
Despite the name, it doesn't work that way.

Hugh Jenkins
12-21-2011, 08:33 PM
The insulating cement comes off as a shell and tends to bring a layer of the fiber with it, but it is rewettable and will form a moldable paste again, except where it might have gotten really hot like right next to the gathering port or burner. I don't generally do that because of the fiber that gets included, but I have sprayed and retooled the already placed material when resetting the cap after a crucible change.

Pete VanderLaan
12-22-2011, 09:20 AM
Pete, I am crushed. I have lived with the glow of your comments since your visit and now I find out you not only don't remember, but would not say that again anyway.

I also have a correction to make. The material I use to coat fiber layers is an insulating cement. The coating cement is a very hard final coat that I do not use but can be used as a water barrier.
**********
Hey Hugh, you should wrap that furnace with copper coils and get your hot water...

Sky Campbell
12-22-2011, 10:19 AM
Better yet stop blowing cold air on top of your furnace and collect that one percent in hot water.

Pete VanderLaan
12-22-2011, 12:42 PM
The cold air is a real conundrum. The element ends have to be cooled and so do the straps. We've got nine inches of fiber up there. Running a plenum like Rollin did doesn't appeal to my curmudgeonly partner. I am going to see how the direct approach works. Charlie is a real stickler about heat transfer and he thought it to be totally acceptable. Time will tell. It's really nice to have this furnace just up the road so I can monitor it easily.

I was joking about the hot water with Hugh and he knows the joke.

John Riepma
12-22-2011, 02:30 PM
Let me get this straight: your partner is a curmudgeon?

Pete VanderLaan
12-22-2011, 02:39 PM
Oh, hmm, you noticed that did you?

Hugh Jenkins
12-24-2011, 11:47 PM
Thanks for reminding me Pete. We have been having such lousy weather that I have no solar hot water. So I am wrapping the furnace up for Christmas with copper ribbons to heat my hot tub. I'll bet you feel sorry you brought this up, but I will be happy and warm again in a few days.

Actually, I will be using the exhaust, which is convected heat not conducted. But if this issue allows us to re-laugh yet again, it is worth the provocation.

Best to everyone in even colder places.

Hugh

David Sandidge
03-12-2012, 08:16 AM
Where can I find super stick 1900?

Hugh Jenkins
03-12-2012, 02:05 PM
Ask your refractory dealer or furnace repair company. It or similar products are actually quite common. I have had to order in from California. I actually think it is available in Honolulu, but I would have to wrangle with the refinery repair guys, and one bag is not in their vocabulary.

Tom Clifton
03-12-2012, 07:22 PM
I bought a role of Ceramic Fiber to wrap around my Electric furnace to increase the heat retention... Once I wrap this product around the furnace, is there something I can put over the fiber to reduce it's ability to go airborne?

Mark Lauchner has an interesting approach to this. He sprays a couple coats of automotive 'high temp manifold paint' on the exposed face of the fiber, then wraps heavy gauge expanded steel over the fiber to give it mechanical protection. Then one more shot of paint. No new hot-face, and the fiber is well protected against mechanical damage, and you don't get burnt quite as bad when you back into it...

Yours truely
Waffle-Butt in St. Louis

Ben Solwitz
03-13-2012, 10:03 AM
I think they were suggesting that if the furnace is currently covered in metal, covering the metal in fiber will make a new hot face and destroy the metal. Doesn't matter how you treat the outside of the fiber.

Pete VanderLaan
03-13-2012, 11:29 AM
If you are getting burned at all, it's really under insulated. I like a surface I can put my hand on. Metal does seem to feel hotter than other materials

Pete VanderLaan
03-13-2012, 11:29 AM
I think they were suggesting that if the furnace is currently covered in metal, covering the metal in fiber will make a new hot face and destroy the metal. Doesn't matter how you treat the outside of the fiber.
********
correct.

Ben Solwitz
03-16-2012, 05:36 PM
Metal burns you more because it is a better conductor of heat than a lot of things. It can transfer a lot of energy into your hand very quickly. When you brush up against hot glass for example, it doesn't transfer nearly as much energy to you because it's a poor conductor, especially when it isn't really molten. It's a much better conductor when it's really hot.

Hugh Jenkins
03-17-2012, 04:56 PM
It's the combination of high specific heat and high conductivity that gives metal a high burn potential.

But if you think that hot glass wont just seer the hell out of you, think again!

Pete VanderLaan
03-17-2012, 05:23 PM
I'm with you Hugh. Glass burns quickly and thoroughly just fine. It's that little snapping noise I really hate before the neurons report that is.

Ben Solwitz
03-18-2012, 02:23 PM
Ah true, it stores a lot of energy as well.