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Ceramic Mold

Posted: Mon Feb 16, 2004 3:34 pm
by Bellknap
Newbie question...
I have looked into the archives and wanted to claify. Can I use some of the bisque molds they would have at those you "paint it and fire here" stores? I would be slumping at a max of 1300.
I know I would need to make sure the bottom where the glass would go into should be smoth and balanced and that I would need to drill a couple of holes, right? Can I just drill with a dremel? Any other suggestions. The molds sold specifially for slumping are pretty pricey and since I am just starting out hate to spend tooooo much mulla. Thanks so much, Lydia

Posted: Mon Feb 16, 2004 5:30 pm
by Geri Comstock
Probably. The problem with these molds is that you have to fire them very slowly and can't vent the kiln or you risk breakage of the mold. I had a bunch of these and many of them broke for both of the reasons above.

I wouldn't fire any of these things faster than 250F per hour and I wouldn't vent the kiln.

Good luck!

Geri

Posted: Mon Feb 16, 2004 7:33 pm
by cherylka
I own one of those pottery shops, and have tried many different pieces as molds. Poured bisque is pretty fragile, as the previous poster suggested. If however, you get "Pressed" bisque, it lasts for many firings, and I fire with a 500 dph ramp with no problem. Much of the dishware I carry is Italian pressed bisque.

c

Thanks

Posted: Mon Feb 16, 2004 7:43 pm
by Bellknap
Thanks ladies, good information to have. By the way, I love those paint and fire shops. One of my foundest memories is spending an afternoon with my favorite little cousins painting our hearts out. I am in Ohio and they are in NC, so it made it really fun to get my plate in the mail! Lydia

Posted: Tue Feb 17, 2004 12:56 am
by Lynn g
I've used some plate molds with no problem. However, I bought a large (about 16-18" diameter) plate and tried to bisque-fire it in my 23" kiln, only to have it crack. I went back to the pottery sotre, and they told me large molds often don't fire well in glass kilns. So I had them fire the next one...cost about $5. I just took my drill in with me and drilled it there before they fired it. Problem solved.

Lynn g

Posted: Tue Feb 17, 2004 2:48 pm
by Lauri Levanto
Bellkanp,

You can drill bisquit fired clay with Dremel.
It is easier, however, to drill it before firing.

For bisquit clay you need preferably a diamond bit.
The only one I have seen for Dremel is ball shaped.
It does not effectively drill straight.
Start the hole with the drill at an angle.
When going deeper, rotate the drill is a snall
circular movement, so that the drill bit bites
with sides, not with the tip.

If you use steel bits, the carving type(!), you may
need a couple of bits per hole.

-lauri

Re: Ceramic Mold

Posted: Tue Feb 17, 2004 3:03 pm
by Paul Tarlow
Bellknap wrote:Newbie question...
I have looked into the archives and wanted to claify. Can I use some of the bisque molds they would have at those you "paint it and fire here" stores? I would be slumping at a max of 1300.
I know I would need to make sure the bottom where the glass would go into should be smoth and balanced and that I would need to drill a couple of holes, right? Can I just drill with a dremel? Any other suggestions. The molds sold specifially for slumping are pretty pricey and since I am just starting out hate to spend tooooo much mulla. Thanks so much, Lydia
About half of my molds are bisque-ware from the local paint-your-own pottery store -- including a nice big 18" bowl. To date I've never had one break or crack. It sounds like I've been lucky :)