Forge Construction?

L6steel

L6steel

Joined
Sep 23, 1999
Messages
5,855
My heat treat oven is made out of fire brick that are mortared together with what I imagine is castable refractory. It can get up to 2500 degrees and at 1975 you can touch the outside of it without being burned.
Why do so many folks build their forges with koa wool instead of building it like my heat treat oven??? Thanks! Michael
 
I'm just in the process of building a new forge and after doing some research,i t seems that using koa wool allows the forge to heat up faster and cool down faster,difinately a advantage with many users..also useing wool allow more flexable designs eg. round chambers verses square ..I,have decided to build mine with castable refractory; based on don foggs design,,hope i,m on the right track
 
Michael, I think Allan is on to something. The quick heat up and cool down is a plus for my forge because it is portable and the kaowool allowed me to utilize an existing object, namely a freon tank to make a small forge. Your forge is perfectly acceptable and has points of its own. If you have a permanent location for a forge something like what you built is a good idea plus the mass of the forge allows you to hold a more even temperature and allows you to cut you forge off and restart it over a short period without relighting it with a flame.
Like most things I suppose there is no "ideal", only what works.

Allan, a Don Fogg style verticle forge with a high quality castable refractory sounds ideal, especially for making damascus. In addiiton the design seems to alllow most of the oxygen in the forge to be burned up by the time the gases reach the upper portion of the forge where the access hole is. Forced air blowers definitely allow more control of temperature and atmosphere. I use a forge based on the Donn Fogg style regularly at a friends shop and love it. I believe the key is having a blower that puts out enough volume for the size of the forge.

Maybe others with more exerience will chime in and say what they think are the best points of whatever forges they use!

Guy Thomas
 
If you get silicon carbide in sand form(I make mine from smashing up old cutting disks) and you mix it in with fireclay(very high silicate clay), it makes a forge liner coating that is amazingly insular and very very durable. It will take as much heat as you can throw at it. I have melted a firebrick in my charcoal forge by accident before, but this liner material doesn't flinch from that sorta heat(I think around 3500-4000 degrees...). I prefer this setup to kaowool. In my case I am not moving the forge around though. If you think you will move it much, you'll learn the value of kaowool very quickly.
 
Michael-

I guess I will chime in with some words on my new forge. My friend and fellow forumite Bill Cottrell refined some of the designs out there for a vertical forge and built his own. After seeing his I REALLY wanted one...and Bill put one together for me. We have a couple changes and I'm hoping it will work out great.

It is a 14" stainless pipe that's 18" tall with a stainless cap welded on top. It sits on top of a mold that holds a dished out castable refractory bottom.

There are 2" of kao-wool going around the sides, and 3" on top. Bill welded up some small pieces of stainless that go into the forge at the doors to act as troughs to channel the flux down onto the castable and away from the kao-wool.

It has a Dayton blower on it with a gate that Bill made.

It gets hot! I have a pyrometer set up with it but it's only been fired once for a few minutes to set the lining a little.

It seems as though this forge is the closest thing to the best of "both-worlds" a guy can have. I will definitely let you guys know how it works out!!!

And thanks Bill!!!
Nick

ps- Bill does NOT want to be a forge builder, so please don't get any funny ideas about him building you one :)
 
I had a problem w/ my forge where the flux from billets dripped down the side into the Kaowool liner. (I was working a chain billet that I used a LOT of flux on) Needless to say the wool was no longer there after that. So on Nicks forge I welded a stainless trough into the door with a lip that sticks past the wool and turns down a little on the end. The turned down end should make liquid flux drip off the edge onto the floor without getting on the walls and eating them up.

My own forge got the wool torn out today and I am starting a castable top and side walls for it. Since I already had the castable I thought I'd give it a try. If I don't like the time it takes to preheat the forge I will knock it out and go back to the wool. this is a continuing R&D project on our forges.

plain ol Bill
 
You must log in or register to reply here.
Back
Top