I began this project approximately 4yrs ago *sigh* and recently tripped over it in the shop ;-)
The first photo depicts the front of the 12" diameter forge with the front access door closed. The second photo has the main door open. And, the
third photo is of the rear of the forge, illustrating a sliding pass-through for long bar stock. The burner assembly is a Rex Price unit.
I have some ITC-100 refractory coating and plenty of 2" Kaowool ready to install - that is where I left off.
My question is: do I coat the Kaowool with the ITC and then lay the refractory brick on top of it? Or, do I make a cut-out in the Kaowool and lay the
refractory brick directly on the forge's steel floor? FYI: I tried to follow the basic principals of forge design as outlined by Ron Reil when sizing the burner to the forge volume. Any tips and suggestions from those whom have successfully built their own gas forge would be greatly appreciated! I would like to wrap this thing up and expand my endeavors a bit :-)
Dino
Forge 1:
Forge 2
Forge 3
Dino, Welcome to the club-
Dino,
Welcome to the club- I've got a couple of half-completed forges I need to get busy and finish.
For my gas forges, I generally use Kaowool for the walls and ceilings and kiln shelf for the floors. I've found that the silicon carbide kiln shelf holds up the best to flux, but the synthetic mullite ones are almost as good and much cheaper. Hard firebrick is also perfectly fine. I also sometimes use strips of kiln shelf on the sides of the forge, up about two or three inches, to protect against tearouts from errant pieces of stock.
When I build my round forges, I usually wrap two layers of 1" Kaowool inside the shell, all the way around. Once it is in place, I put two or four (depending on forge size) kiln shelf supports to support the forge floor. I usually carve out holes in the Kaowool to accomodate them, and also grind the bottoms of the supports to match the curvature of the shell. Then I place the forge floor in place on the supports and fill any open areas under it with scraps of Kaowool. I also tuck scraps of Kaowool around the sides of the floor to wedge it in pretty securely.
Following the floor assembly, I put the Kaowool in the rar end of the forge and make any necessary cutouts for pass-through openings. When all that is done, I spray the Kaowool with a water mist and then paint on two coats of Plistix 900. I try for a thickness of about 3/32 to 1/8" on the Plistix. I use it because it is a third the price of the ITC-100 and is actually considerably stronger in my experience. For maximum efficiency you can fire the Plistix and then coat it with a couple of coats of ITC-100 for the IR reflectivity. Your ITC-100 wil go twice as far or more putting it over the Plistix instead of directly onto the Kaowool. I get the Plistix from Larry ZOeller at zoellerforge.net.
That front door is going to be a challenge to insulate unless you use rigid Kaowool board or a similar product. I've tried about every method I could think of to get Kaowool to stay on a flat surface and none work for long. The best so far was the one where I welded on a rim about 3/4"high with a 3/8" return to tuck the Kaowool under. I used pieces that were significantly oversize so I had to relaly cram them under the retainer and then coated the thing with Plistix 900. ITC-200 would be beter for this as it actually is supposed to adhere to steel. Never tried it so I can't say.
A piece of Inconel screen would hold the Kaowool in place very nicely, if money were no object. :-)
Well, there you have s few things to think about. If I can be of further help, just ask.
Rich