I made this one to make blade forging more efficient than using the barbecue...
It's a steel box I found, with some marble inserts to create a thermal jacket inside it. The tube to the right is the column of an exercise that has been modded to create a way to blast air in to up the heat. Here, it is shown with a hot air paint stripper. This is OK, but isn't really pokey enough...
In practice, the air was blasted in from the front hatch. This was much more effective
The hole in the original tube was way too small, so I reamed it out to the right size with die grinders
Till it matched the girth of the blower that would be inserted later.
And the weirdness that is Vermiculate. This is super fluffy mineral granules that feel like polystyrene, but are not affected by heat.
With a lid on top...
That's about it
In use, I used lumpwood charcoal.
After heating in the mini-furnace, this took a battering on the anvil...
The same chisel after a good hammering.
Once flattened out, the blade face was created by hacking it off with the angle grinder.
This one is an old file.
It has been shaped with the grinder#
Eventually after a lot of grinding and polishing...
They become all shiny and lush like this
Before and after