My forge build will be used to heat treat tool steel for wood turning tools.

The forge will be about 125 cu-in heated with a Frosty 1/2" T-Burner. Insulated using 2 layers of 1" Kaowool and rigidized.
The kaowool will be treated with Plistex.

I suppose the use of a floor would be well. My reading in this forum gives info for High Alumina Shelves $$. For my limited use of the forge, I'm open to alternative materials?

1, Mullite Shelf material as an alternative to High Alumina?
2. How is this material cut to size? I don't have access to a tile saw?

Ed...

You would be better off with Kast-O-lite 30 refractory. Mullite is nothing more than Low alumina content refractory, which no amount of extra long heat curing is going to transform into anything worthwhile.

While you are working on building a forge plan that you are going to use it for more than just heat treating.  Build a good forge that suits your needs but will serve you well when your interest expand.  Check out the attachments on the Forge Supplies page at www.WayneCoeArtistBlacksmith.com.

Let me know if I can help you.

Wayne

Here's your man Ed. You can get good plans and the necessary materials to build it right for reasonable.

Frosty The Lucky.

I've cast a floor for my forge using Mizzou. It's 1/2" thick, 4" wide and 11" long. It's still in the form.

I've read the instructions for curing Mizzou which will take days. Besides, don't have a way of measuring temperatures above 500 deg say less at 75 deg per step.

Can someone give me an alternate curing method?

Ed...

I wish I could Ed but I've worked with Mizzou. I've seen it used in forges for I don't know how long though and I don't think any of those guys ramped the cure temp up or down. 

This is speculation so do NOT take it as THE right way to do this. Okay?

Give it plenty of dry time, hang a light bulb in the forge or whatever to assist. Being warmer than ambient temp will dry anything faster.

First firing should be a few minutes, or maybe burn a couple charcoal brickettes in it. Just bring it up to a couple few hundred degrees, maybe the kitchen oven is good.

Second firing bring it up hotter for longer, say pushing 400f or better and give it half an hour or so and let it cool slowly.

Third firing push into the red and let it cook for a while a couple hours even maybe.

She should be good to do after that.

Bear in mind that is just a generic curing strategy I've had some success with but not with Mizzou. I've never worked Mizzou. The refractory I've started using is a water set and doesn't require a cure cycle, Kast-O-Lite-30 and even then I give it a low temp firing before bringing it up to forging temps.

I sure hope one of the guys here who use Mizzou speaks up I'd hate to have you rely on my advice in this and have it turn out badly.

Frosty The Lucky.

Thank you Frosty,

What you propose sounds pretty good to me. I removed the cast from the mold today. Gotta find a release better than cooking spray.

I have the casting in front of the fireplace hearth at 98 degs. In a couple of days, I'll use our toaster oven and bake at a couple hundred degrees. The oven has a very good temperature resolution. 

I'll work with this floor casting before trying to cast the door baffles. Plan to use Kast-o-Lite 26 and 30.

Ed...

 

I'd get as hot as possible at the 100 deg/hr rate recommended in your oven, then candle it slowly in the forge.  As long as it isn't load bearing, or restrained from expansion and contraction I've been petty successful with that.  Remember to vent the oven periodically to allow the moisture out.  You will be surprised at the amount of vapor driven off and the temperatures it still is produced at.  I know I was.

I used to use my annealer to fire Mizzou.  If you know someone with a temperature controlled kiln, that will work well also.  Recently preheated a Mizzou ribbon burner in my heat treat oven.

Thank you Latticino for the reply. I'll give that a try.

Ed..