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I've done the search and found a lot of good info on using plaster, paper clay and other materials for kiln carving molds, but I don't really want to take the time to go thru the trial and error process of learning how to do that.

I want to use my CNC router to do some very detail carving for a kiln carving mold. Is there a source for pre-made high quality refractory blocks that can be carved and then cured. The mold will be used for many, firings and needs to be able to hold fine detail. I will be making ornament sized pieces.

Thanks
Perry

Kopperwood wrote:I want to use my CNC router to do some very detail carving for a kiln carving mold. Is there a source for pre-made high quality refractory blocks that can be carved and then cured. The mold will be used for many, firings and needs to be able to hold fine detail. I will be making ornament sized pieces.

We're doing this using vermiculite board and Ceramaguard (and have worked with plaster/silica as well). In fact, I'm teaching a class on the technique in a couple of weeks: http://www.kilnforming.com/workshops/14 ... al-july-13

Kaiser lee board. Stan Harmon uses that. Get up with him. Comming to the obx any time? R.

Try Unifrax Duraboard. Treat afterward with colloidal alumina. I usually lean toward HD boards, but I know of companies that use LD board and CNC routing. The primary reason they use LD is that it is the only style available in oversized boards.

Thanks, for getting me started.

Brad, sounds like a good class.

Perry

If you work with vermiculite boards, I have learned how to make an additive paste that can be sanded down. Take coarse sandpaper and make dust. Mix it in with colloidal silica to a putty, apply, dry, sand, and fire. You could use this to repair any anomalies from the CNC routing. I see no reason you couldn't do this with any type of board fibers.

Bert Weiss wrote:If you work with vermiculite boards, I have learned how to make an additive paste that can be sanded down. Take coarse sandpaper and make dust. Mix it in with colloidal silica to a putty, apply, dry, sand, and fire. You could use this to repair any anomalies from the CNC routing. I see no reason you couldn't do this with any type of board fibers.

Thanks for the tip on the paste. I'll give it a try.

FWIW, we haven't seen any issues with CNC and vermiculite boards. But sometimes vermiculite board chips if mishandled, the paste could come in handy there.

Brad Walker wrote:

Bert Weiss wrote:If you work with vermiculite boards, I have learned how to make an additive paste that can be sanded down. Take coarse sandpaper and make dust. Mix it in with colloidal silica to a putty, apply, dry, sand, and fire. You could use this to repair any anomalies from the CNC routing. I see no reason you couldn't do this with any type of board fibers.

Thanks for the tip on the paste. I'll give it a try.

FWIW, we haven't seen any issues with CNC and vermiculite boards. But sometimes vermiculite board chips if mishandled, the paste could come in handy there.

I was in a shop helping out one day, and my project was to resurface a Best Mix mold. I rubbed the paste in, dried it, sanded it, and fired the mold. It worked beautifully to make a smooth surface. I was surprised considering the 2 materials must have different expansion characteristics. I am told the fix was durable. It does need kiln wash though.