I actually spent about a year developing my process for repeatable and reliable results. I would take 1/8 inch flat stock and surface grind them so that they were dead flat. I would then CCH them changing one variable at a time checking for colors and warpage. Sometimes up to two quenches a day; so a lot of time, money and energy went into setting up my system.
I remember talking to Oscar Gaddy about this, our first conversation he chuckled.. Told me not to do it . After a while he was quite helpful.
My set-up is a standard ceramic kiln, generally they can be had cheap on the secondary market, some bored housewife tries pottery for a month or so then gets tired of playing. I’ve got four kilns in my shop all from the above.
I use a digital kiln controller on the kilns, good ones are not cheap, but it will maintain the temp +/- 2 degrees. The first one I bought, something like $400 15+ years ago, now I just build my own using inexpensive PID controllers.
My crucibles are Ľ inch stainless steel, I’ve designed my quench tank system where the lid is removed and the crucible drops to a pre-determined distance from the water all in one movement. Again..consistancy.. Always the same each and every time.
Charcoal is mixed using a concrete mixer.
I keep 4 standard wood/bone ratios on hand; one for bold bright colors, two different mixes for Winchesters, and one for Colts.
Lots of variables in getting colors: Water temp, quench temp, wood/bone ratio, bone char size, blocking, drop distance between crucible and water, quantity of O2 in the water etc. And even then there are no guarantees… one side of the frame may only have browns and blues, the other side looks like Picasso puked on it… all the colors of the rainbow.
