[WNC Goater]

Still, putting it at warm, cool, room temperature or whatever, and very, very slowly into LN is still thermal shock. Okay, I get it can take it. And maybe that doesn't qualify as thermal shock. Maybe it's like the frog and boiling pot analogy!

My point however, is that it can take that without breaking and yet if it is just left at room temperature without tempering after quenching it can spontaneous break. Supposedly anyway. I've never experienced that, I just know that's what "they" say and so I've gone from warm to the touch from the quenching oil into the tempering oven. I've read of people deciding to leave blades "until tomorrow" to temper and find them broken the next day. That's a pretty extreme reaction for steel in my mind. Everything I've read or heard says go from the quench immediately into the temper, do not leave them lying.

Forget the physics behind it or the why...That you can NOT safely leave them lying for a time at room temperature before tempering but CAN put them into LN blows my mind.

Anyway, back to the oven questions. It would be handy to have one at home. As far as cooling down the HT oven, I suppose the experience would be just like my burnout oven. And I figured that was the answer. The thing heats up and the kiln lining absorbs and holds heat for a time. It will be that way with any oven but particularly one designed to heat up to 2000?. By necessity they must hold the heat inside to even be able to heat to those levels.
Maybe if I get flush with cash (ha, ha!) I'll consider buying one for home. As it is, everything I've made to date can be put into the oven at work and tempered with the toaster oven. Longer forged knives can be made with hidden tang so the OAL of the blade doesn't exceed my current oven's capacity.

This butcher knife I have an order for isn't typical, it is a full tang, and will be made using Alabama Damascus, which can be HT in a forge.

Thanks for the HT oven info.