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Hi
Has anyone used Skamol as a dam for kiln casting? Whad'ja' think?
And where do you buy it?
Thanks in advance
Steve Zorn

SteveZorn wrote:Hi
Has anyone used Skamol as a dam for kiln casting? Whad'ja' think?
And where do you buy it?

It works fine. So does fiberboard, Ceramaguard, mullilte, or lots of other products.

Bullseye sells Skamol. I'll also be selling it in about a month.

For those that don't recognize the company name Skamol, the product is actually vermiculite board or panel. Bullseye is recommending Skamol, and selling their board, as a high quality, asbestos free board for building boxes to cast into. The big advantage is that you can screw the boards together, cast into them, then unscrew them to release the glass and reuse them. The boards cut easily on a table saw. See Bullseye's recent bulletin on the topic. I think it is number 5.

I have been testing the lower density board. I found it at a local refractory supplier, (MUCH cheaper than BE), that didn't have the 600 lbs/cubic foot density that Bullseye recommends. I don't know if what I'm using is 375 or 475 density.

It has worked pretty well so far. I broke two opposite ends of one box when I put a piece of glass in that was too big. The glass expanded as it heated up and pushed out enough on the boards to break them. I was impressed that the screws held and the corners stayed together. I made sure I was using stainless wood screws that have a wide space between threads for lots of grip. Using smaller pieces of glass to load the mold, I haven't had any problems during firing. I have been casting pieces up to about 2.25 inches thick finished glass. I did break one board by hand testing how much it would bend. (Not much.)

I have thought that I might soak the boards and fill the screw holes with rigidizer to strengthen them some. If boards bend or break when I cast deeper I may try that.

ch

I just bought 6 vermiculite boards from BE(Skamol)
$30 a sheet 24"x 36" , but the cost of the box was $60.00 three in a box!!! . Plus $84.00 postage
A$50 refund if you send it back but with the postage for oversize boxes from Pittsburgh my UPS man said it was not worth it.
I will be attempting to make some negative castings when I get my new kiln up and running. I'll let you know how it works out.
Judi

Please let us know how it works for you, Judi. I know that Marty Kremer is also using the board as a kiln shelf (he's using the 2" thickness).

The postage is the main reason I'm going to try to carry it. I'll be selling the board at the same price as BE, but will offer it mostly to people east of the Mississippi. That will cut the postage dramatically. And we'll also be offering a lower delivery rate for people in the DC area.

More details on all this when I finally get the board in -- it'll probably be mid November before the next boat arrives from Denmark.

Charlie,
You might try reinforcing the wall by backing it up with a hard brick or you could build a flying butress!

jerry flanary wrote:Charlie,
You might try reinforcing the wall by backing it up with a hard brick or you could build a flying butress!

I was thinking of painting five layers of Mold Mix 6 around the outside, carefully, with a tiny little brush so I fill in all the voids, then embedding the entire thing in sand. That will hold all the glass I want in. It will just be lifting the whole thing into the trash that will be the problem.

ch

Charlie:
I've been working a little with the 475 compressive strength material and find it to be much more flaky and brittle than the 600. The distributor in Charlotte, NC was kind enough to send me a sheet of the 475 to test out. It's easily cut with a chop saw but throws out a lot of dust. The screw holes would probably strip more easily with the 475 material were taken apart and put together frequently. I've put in my order for the 600 material through Brad, with local East Coast delivery through our local guild. Is there a source for the 2" thick material other than the US distributor? How big a mold are you making?
Nikki

Nikki O'Neill wrote:Charlie:
I've been working a little with the 475 compressive strength material and find it to be much more flaky and brittle than the 600. The distributor in Charlotte, NC was kind enough to send me a sheet of the 475 to test out. It's easily cut with a chop saw but throws out a lot of dust. The screw holes would probably strip more easily with the 475 material were taken apart and put together frequently. I've put in my order for the 600 material through Brad, with local East Coast delivery through our local guild. Is there a source for the 2" thick material other than the US distributor? How big a mold are you making?
Nikki

I have to be very careful with the stuff I've got. I can tell that the screw holes aren't going to last forever. That's why I may try to rigidize the surface. The key to a strong screw attachment is to drill a clear hole in the outside board and a narrow pilot hole in the inside board. In other words, the threads slip through the hole in the outside board then grab the edges of the hole in the inside board. The head of the screw is what holds the outside board, not any threads.

I don't think it needs to be much stronger to contain the glass though. I haven't been screwing on a bottom board, as Bullseye describes, and the molds easily contain glass 2" deep without warping. So far my molds are about 18"x 11"x 4". I'll probably back them up with a brick or two when I build longer walls. Fluid pressure is a function of the depth of the liquid. So the big strength issues come in when you try to cast something deep.

It is hard to find places that will sell small amounts. They have to buy a minimum of a full pallet from Skamol, and the guys I bought mine from don't seem to be selling much of it. The pallet they have is the lighter stuff and they don't seem inclined to buy another pallet of the 600. I think they do have 2" light density, though. If you want to find a local source try the yellow pages for refractory supplies, insulation, ovens, furnaces, fire protection and fire door manufacturing. If you can find somebody that has it you will save a lot of money.

ch

I'm curious about using Skamol as a kiln shelf. Would like to know what luck Marty Kremer if having with it. Anyone guess how long it would hold up for? Would imagine 18" paper/blanket over the top would be good. Maybe even rolling it (paper) flat after first use to reuse more conveniently.

Britestar wrote:I'm curious about using Skamol as a kiln shelf. Would like to know what luck Marty Kremer if having with it. Anyone guess how long it would hold up for? Would imagine 18" paper/blanket over the top would be good. Maybe even rolling it (paper) flat after first use to reuse more conveniently.

The boards are 1'x3' by either one or two inches thick. Not wide enough for a functional kiln shelf.

charlie holden wrote:The boards are 1'x3' by either one or two inches thick. Not wide enough for a functional kiln shelf.

The boards are available both 2 feet by 3 feet and 1 foot by 3 feet.

http://www.skamol.com/pdf_front/v_slabs.pdf

Why is this product better than using regular dams from mullite backed with kiln brick or posts? It would certainly need some kind of superior qualities to justify its cost????

Carol

Carol wrote:Why is this product better than using regular dams from mullite backed with kiln brick or posts? It would certainly need some kind of superior qualities to justify its cost????l

The vermiculite board is $5 a square foot retail. Mullite shelves are around $10 to $20 a square foot. So unless you already have the mullite strips hanging around, the board is cheaper, not more expensive.

If you do have the strips hanging around (from a broken shelf, most likely), then the board may still have a few advantages. First, it can be screwed together to form the mold box, making it a bit stronger and less likely to come apart when firing. Second, it allows the glass to heat more evenly than mullite backed with kiln furniture, making for better annealing and less chance of thermal shock. And finally, it takes up a bit less room in your kiln, which may or may not be important.

(Ceramaguard, by the way, is cheaper than either mullite or vermiculite board, especially considering shipping costs. Works just as well for a mold box, too. On the downside, while it's relatively long lasting, it probably doesn't last as long as the other two products.)