Last forge question

[JTknives]

well i ordered the rest of the forge stuff i needed from darren ellis. it turned out a lot cheaper then buying one and plus i get to build something which is allways fun right. so my question is this. im going to be running a forced air burner in my forge that is made from a old air tank that is 9" wide by 16-17" long. it has slightly domed ends that make up about an inch on each side. what im wondering is this, should i put 2 layers of 1" Inswool HTZ 2700 or 1. if i do 2 that will make the chamber around 4" accross and if i do 1 it will be 6". but i will be adding

Ins-tuff Ceramic-Fiber Rigidizer
Satanite Refractory Mortar
Bubble Alumina
ITC-100

so i am guessing all that will what, maybe add 1/4" - 1/2" per side. so that makes my chamber eather 5" - 5.5" or 3" - 3.5". Is one layer fine or must i have 2. i would like the space of just 1 layer because i think 3.5" is kinda small for a chamber size, makes it kinda hard to keep the blade out of the direct blast of the burner. IF i do the one layer im going to make a 6" hole in the front and make a door out of 1" Insboard 23 HD with a hole in it. then make a 4" hole in the back and weld tracks onto the tank to hold another 1" thick insboard to seal it off but will alow to be removed. i would also think about using 1" Thick Hard Fire Brick for the floor to protect it from any flux. what do you think?

 

[M.Griffin]

I would go with one layer of Inswool. My forge is nearly the same dimensions and I went with one layer and the chamber is none too big. It does get pretty hot on the outside of the forge though. My next one will be 11 or 12" diameter and two layers of wool. I think you are right that your blade will be right in the burner path if you go with two layers. I am also regretting not making my forge with hard fire brick floor, so I would do that too if you plan to forge weld or not. I didn't plan to forge weld, but ended up doing it later on, so you never know. Good luck. By the way, I am a rookie so take all this for what it is worth, which isn't much.

-Mike

 

[JTknives]

It looks like darren ellis only uses one layer of insulation on his forges. Am i right?

 

[1984nitro]

I put personally would use two My forge is alittle under 4" at the opening and I have know problems and it stays hot. The other thing that I was get some cement brick 11"x9"x2" from home depot and put them around the out side to help insulate.
Eric Knight