make it. Plenty of recipes around, I recommend (w/w/w) 110 kaolin/480
sodium silicate/410 graphite powder. Mix real good!!! use within 3
hours. Bake for 45-60 minutes at 160C. It's good to 350C, chemically
resistant and conductive as a side bonus.
Make sure your powders are fine enough for your dimensions!
Good luck
Alex