OK ya'll blacksmiths i need all your .02 worth on this. I can get a roll of Kaowool insulation for $150. If i go that way i have to use the Satinite to protect the Kaowool. (Forgive my misspellin') now i had a hair brain idea while workin' out. Why can't i use refracotry clay and i know that i can get that stuff for $12.00 per 100 lbs. Now I've got a piece of 12 water main .375 in. wall thickness. See the water company left that piece out there too long so it ended up in the back of my truck. so i want to know whether i should go the Kaowool route or the refractroy clay route. i was thinkin' about doing a 2" lining of whichever i choose. Intuitively i don't know which one will heat up faster and all that. weight ain't a limiting factor, and i'm gonna use the public pressure natural gas with a blower to heat this little baby. When i do get this thing up and runnin' I'm lookin' forward to makin' mokume and damascus!!!!! THANK YOU VERY MUCH

You say you want to make Damascus and Mokume in your message. That alone is the key to your answer. Kaowool is great for fast heat ups and cool downs. I have it in my small forge that I use for heat treating. The problem with Kaowool is the fibers it blows out of the forge and the fact that the flux will eat it up. By putting Satanite on it you will protect it from the flux, FOR A WHILE. But it will still go bad fairly quickly, especially if you are like me and keep poking the walls with your steel. Not sure how much a "ROLL" of Kaowool is but it should not take anywhere near $150 to make a forge. If you go that route, look for a cheaper supplier that sells by the square foot.

Refractory clay is great for coating the kaowool but I have never used it as the only refractory, if you get high temp stuff it would probably work ok and not be as sensitive to the flux.

You could also make it out of fire brick. A lot of people do that also.

If it were me, I would go for refractory cement. This is a high temp castable refractory that you can get in temp ranges of 4500 degrees up to 8000 degrees (probably other temps as well). The 4500 degree stuff will work great and is about 60 bucks for the avarage sized forge. You can really abuse this stuff for a long time before you will have problems with it. I know of one forge that has a thick coat of flux on the bottom of it from years of use and it still works great. You can't damage it by poking it with the steel either. The drawback (if you see it as one) is that it takes a long time to heat up. This is ok though because that means it also takes a long ime to cool down, and if you need to aneal anything you just close the forge door and go in the house. Another benefit is that in a kaowool forge you add a large piece of steel and it will cool the entire forge down and you will have to let it heat up again and then heat your steel. In a castable forge the steel will not make a drastic temp drop because of all of the stored heat in the cement. So it really becomes more efficient once it is hot.

I know of one guy that got a 12" pipe and put a 8" paper roll inside of it. He poured refractory cement into it to get 2" thick walls all the way around. Then he added 2" of Kaowool to the outside of the pipe and slid the entire thing inside a 16" pipe. It has been running for years also.

Hope this helps.

Thanks a bunch there Bob. I figured there were good pros and cons to both insulationg materials. Yeah i'll try and find somone else that carries Kaowool.
So the refractory clay may take a little longer to heat up, but that isn't a draw back, So thanks a bunch.

Nathan, I don't know where you are located, but I finaly got ahold of some Kaowool from Atlass Insulation in Jackson Mississippi.

It cost me 15 dollars for a remanent piece 2' x 6', and a couple of pieces of Koaboard. You should be able to find some place that has remanents.

Yes flux does eat up the lining, but I solved the problem by making an adobe botom and putting a layer of kitty litter in.

Hope this helps...

I use refractory plaster in all mine.
It is solid and strong.
The fiber stuff gets eaten too quickly for me.
I make a mess when I work. I need tough stuff to work with.
My time is better spent making knives, rather than working on the equipment.
I want to turn it on and GO!
I use that preheat time to clean the cable anyway.(to burn the gunk out)When the billet is ready to flux, the forge is ready too.
The fiber really doesn't like the flux either, Bob was right.

Geno and Wiliiam,
thanks for the advice, i've settled on a refractory clay cylider and then the kaowool around that, followed by my pipe. i'm gonna try and leave a little space for expansion and contraction but for the most part thats about it. thanks for all the help on this.