Lock looks great.
That's about the same temp we used when I worked at Turnbulls.
1430F was our temp and we had to hold it +/- 5*
Time in furnace was 2 hrs.
Only 2 different mixes.
One was 2 parts wood char / one part Bone char
The other was the other way around.
Mix it up outside on a windy day so the dust in each blows away. You don't want that in the mix. Just the granular char.
No blocking of parts though initially it was done. Warpage was overcome to the point where spacers, blocks and such were not used at all.
The char mix for the next days use was placed in a thin sheet metal box & placed on top of one of the furnaces that had been shutdown late in the afternoon for the day.
Over night the residual heat would dry the mix out for use the next day. Moisture in the pack will cause some spots to appear in the colors and sometimes no color at all.
No bubbles or anything extra in the quench. It was however warmed to 90*F for the quenching process.
That along with the close control on the temp helped keep warpage away.
We still had some through.,,and cracked parts as well.
The really bad stuff never gets mentioned of course!
Colors are possible at lower furnace temps but little or no hardening can result. Warpage or the chance of it was greatly reduced .
That was actually a desired result at one time until shooters actually started using their guns alot instead of just admiring them and close fitting parts started gauling.
The colors on those non-hardened parts wear very easily as well.
There are lots of little ways to change the process and still get results. That's why the mfg'rs all had a slight difference in look. But they all got results just the same.
