[TheForge] crucible furnace

[Jerry Frost]

Terry:

Mike's right on this score, sodium silicate will not 
work for this.

You see sodium silicate in home brew refractory recipes 
for one purpose only. It acts as a binder to hold the 
other ingredients together until they fire properly, 
this is the same thing portland cement does in 
refractory recipies. They both burn out (sort of) at 
high temp but they hold everything else together till 
they fire hard.

If you dome the lid and use a rigidizer, Kaowool will 
hold just fine at high heat. One of my students had 
been hemming and hawing around waiting to get all the 
"perfect" stuff to make a gas forge. We'd made his 
burner literally months before, he had his regulator, 
gage, hose, 100lb propane bottle and a perfectly 
servicable steel table. Still, he wasn't getting up and 
going because he needed . . . (Insert list of materials 
to build the perfect forge of your choice here.)

Anyway I got tired of telling him how simple it was 
(actually I finally realized I had fallen down on my 
responsibility as an instructor.) and just made a 
forge. I gave him a pair of aviation snips and told him 
how much hardware cloth to cut while I cut an 
appropriate piece of Kaowool. We finished in under five 
minutes and proceeded to the next step. I rolled the 
Kaowool into a two layer tube, stuck it with a little 
duct tape then bent the hardware cloth around it and 
wired it together. A few quick snips with the aviation 
snips, some knife work, laid two half firebricks in it 
for a floor, inserting the burner finished the unit.

It was larger, faster heating and more efficient than 
my regular forge and took about 15 minutes total to 
build. We used it for his next couple sessions but that 
was it. I'd already explained the danger from the 
fibers, not panicing about short term exposure but not 
exposing yourself uneccessarily regardless. The lesson 
being learned the forge had served it's purpose and 
went back into my Kaowool stockpile.

Anyway, how it applies in this case is how well the 
Kaowool held it's shape in a high temp environment. If 
you were to use a SS mixing bowl of the right size and 
line it with 2-3" of Kaowool, (+ ITC-100, or whatever.) 
it'll hold up fine.

Frosty
-------------------------------
If it ain't forged
it ain't real.
Wrought iron is.
The FrostWorks

Meadow Lakes, AK.

http://www.artmetalradio.com/

From: "Michael" <michael.a.porter at comcast.net>

> Terry,
> That is not a good idea. If I remember correctly, the 
> various forms of water
> glass liquefy somewhere between 1300 and 1500 degrees 
> F.
> Mikey
>
>
>
> From: >  On Behalf Of terry l. ridder
>
>
> hello;
>
>
>  i also toyed
> with the idea of painting the strips with sodium 
> silicate. i have one
> gallon of sodium silicate.
>
> or i could just line the lid with the homebrew 
> refractory.
>
> -- 
> terry l. ridder ><>
> _______________________________________________
>