anyone used low density fiber board(mineral rock) insulation before?

[Brian Gingras]

I'm changing out the crucible and it gives me a chance to make changes if needed...I was looking at the mayne island glass foundry page and he has a new furnace design using all low density fiber board for insulation. It got me wondering if this material is better at the lower temp locations(outer areas) of the walls? Has anyone used it? did it work better than ceramic?

[Doug Chaussee]

Brian,
I have used it inside an annealer, behind the IFB interior wall. I used a product called Kfac-19 from Harbison Walker. It is a very soft material and stinks more than duraboard when heated up. It is not for direct surface application but I would have to wonder if it would hold up even as a backer to any other very hot material. Don't try to spray it with a ridgidizer as it will turn to a crumbling mess. It's great in the annealer and easy to work with but I would be afraid that it may fall apart in a hotter application of over 1500 degrees or so.

[Brian Gingras]

I was thinking of pulling off 4" of fiber, as I have 14" on the top now, and putting on a couple inches of the board instead. I'm thinking I have more of a heat sink/radiator now with all that fiber, and the board would insulate better at the lower temps beyond 10" of top fiber, and at the same time reduce the masson the top and radiating area...it's $50/bundle, and I only need one so I may try it anyway, can't hurt right? I also built a new 8" thick insulated door this time around to try to cut costs even more, as rates are now at $.16/kwh!

[Dave Bross]

I once built with the mineral wool blanket, which is basically the same as the board.

As mentioned already, it's an incredible mess if you ever have to remove it. I also used it as back up in a glory and chunks and pieces of it would escape out any outside opening as it was dissolving in place. I just use all frax now, one thing to keep in stock and it disassembles quite nicely.

[Virginia Slawson]

Hi Brian,

We've used the mineral board in small annealers and rod pre-heaters--all where it was covered over--the stuff is nasty. For the low price it works well but I'd definitely plan on containing it so that stuff isn't free to float around the room.

Instead, I might cast a cap out of 6-7" of v-bloc mix (over 2" of frax). (Dudley says "you can take a nap on top of this furnace without getting hot")

While the v-bloc is crumbly, it might be contained with a dip-lag wrap. (BTW, if a casting breaks apart, the already cast stuff can be reused by crumbling it and adding it to a new mix). It can also be strengthened with the addition of cement to the mix (although that would reduce the insulative value some). Much more user-friendly than the mineral board.

Virginia

[Brian Gingras]

Well I'm curious as to how it's going to handle the 200-300 degree range, which is what it's going to see...as I look at the Mayne island site I see he has used his for 3 years. My insulation is all cased with fabric anyway...I bought a case and I'm going to try it out...I am trying to cut the losses as much as possible before I flip the switch again.

[Rollin Karg]

Originally posted by Virginia Slawson
While the v-bloc is crumbly, it might be contained with a dip-lag wrap.
Virginia,can you tell me who makes the Dip-lag and where I can get some?
Thanks
Rollin

[Steve Stadelman]

Dip-Lag can be found under the name Re-Wettable Fiberglass Cloth from E.J. Bartells.

[Brian Gingras]

same stuff I'm using on my furnace...keeps everything nice and contained.

[Henry Halem]

Originally posted by Rollin Karg
Virginia,can you tell me who makes the Dip-lag and where I can get some?
Thanks
Rollin Rollin the Dip Lag info is in the book you just bought, pg. 333 (Great Lakes Textiles).

[Rollin Karg]

Thanks guys!!!

[Jeff Mentuck]

Brian,

Is this the green colored m-board? I have used this stuff as a backer for brick in a color pick up oven and in this application it works great, seems like a good low temp insulator and has sttod up well over a few years. I got it up at Zar-Tech, and might stil have a half a case of it laying around.



J

[Brian Gingras]

yes, it's a greenish color, board form but compressible. I got an 8lb density. It's also sold as safing insulation for for blocking and for insulating boilers and other mid range temp applications.

[Virginia Slawson]

Hi Rollin:wave:

Yeah, what they said! Thanks guys!