A question about forge design

[Ninja Blacksmith]

I'm set on rebuilding my forge, the same type, but I want to see if there way to tweak the first design in order to improve efficiency a bit. It's a 6" nominal diameter steel cylindrical propane forge, single venturi type burner, with 1" ceramic fiber insulation caoated with thin (3 - 4 mm) refractory clay. The only major design flaw in the first one (that I'm aware of) is that the orifice placement for the burner wasn't ideal for uniform heating - though at least it worked, more or less. I've done some more homework on forge design, but I'm still wondering about improving flame rotation. Would something like ribs in the refractory clay assist with improving the stability of a flame vortex, or is it all in the placement of the burner orifice?

If this question can be answered in a sticky thread, then I apologize - I must've missed that one when I read through them.

 

[Stacy E. Apelt - Bladesmith]

The flame should enter the forge chamber about 20% forward of the back. It should angle about 15-20° forward. The angle of the burner should be on a chord that is just below the tangent. This will allow the flame to swirl around the chamber as it goes forward. The walls should be as smooth and round as possible. The floor can be flat for the width needed to lay a knife blade down, but the joint of the floor and sides should be curved.

Use about 6mm of refractory coating and a thin layer of ITC-100 mover that.

You should get a good running forge with the above.

Also, consider making a blown burner and putting that on when you make these changes. That way your forge will be much more versatile.