In the video it seems the quench tank was filled just prior to the quench so the temp of the water is fairly cool. The water doesn't seem to be oxygenated as many people in the states do with compressed air. It appears the amount of the char , which keeps the oxygen from the part, is more important than having a sealed crucible. Also by using the heat of the crucible to dry the parts may also normalize the parts also. I've seen the normalizing bring out more color than achieved from just the quench. I've seen decent color achieved with temps from 1325-1425 F. Most of the older American guns frames are some form of a 1020 steel. Are the British frames a similar low carbon steel? We also don't know how long the heat soak was. Is one hour enough? I've been told 1 1/2 -2 hours. Getting the colors you want once is cool, being able to do it on demand over and over is the art I feel.
