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