Pro's and cons of Wool v.s. Brick v.s castable

[Turambar]

I'm curous, it seems that everyone uses kaowool or some equivalent.  Is this because it is better than brick or just more convienient? also how does the performance of these two things compare with the castable stuff.  on an unrelated topic entirely when you guys talk about the salt baths you use what for i asume heat treating or tempering but which, why, what salts do you use and where do you get them? many thanks

[Kristopher Skelton]

I'm pretty new to the smithing thing (just about 2 years of actual practice) but I always have an opinion

I use blanket to line my mailbox (propane forge), and that's covered with ITC-100 clay.  I used to use refractory cement, but it took forever to heat up the forge because the cement mostly absorbs the heat.  The clay reflects much better, and it's way lighter. My forge gets up to temp in about a minute and gets hotter now than before.9 I tried the "spray" method of applying the ITC-100 (as the instructions suggest), but a little water to thin it out and a spatula work much better (see Don's forge buildng instructions for using blanket and clay together).

I use bricks on the bottom of the forge because I can take them out, flip them around, replace them as needed.

 

Good luck, have fun, be safe!!

[Terry_Dodson]

engineerboy do you have a pic of your forge?     i recently bought a metal mailbox to try and make me a 2 burner forge from, so any pics and advice will help.  i plan on using soft brick on the bottom, but not sure whether to use soft brick all the way around or use wool everywhere but the bottom.

[Kristopher Skelton]

I started with a WAY too big mailbox- one of those that the neighbor kids could likely hide themselves in to jump out at you

 

Now my box is too small. They make three sizes and the middle sized one should be just right (for my next forge).

 

Since I knew that I was going to "line" the bottom with brick (it took two of them), I only used the wool on the "top and sides".  Lined with ITC-100 (used that on the bricks, too, just for a little added reflection).  I'll post a pic of the forge both cold and hot when I get home.

 

I have bricks everywhere: My mailbox sits on some regular smooth building brick, and I use the firebrick to shield stuff on the sides from heat and it makes for a great place to lay hot stuff.

[Ragnar238]

Saw a new product in a ceramic supply catalog called "superwool".  It works like Kaowool, but dosn't cause lung problems (it can be disolved by the lung).  Looks interesting, but it's temp rating is only 2200F degrees.  Don't know if that would take the heats we get to, but not having to worry about lung issues is a nice thought.

 

Jeff

[TOM PITTMAN]

Ragnar,

I can vouch for super wool. We got a sample at work that I was lucky enough to convince the boss to part with. I used it on my new forge and haven't seen any problems at all. The same company makes a wet version that dries when on firing.

[Ragnar238]

Thanks Tom!  I'm going to give it a try then.

 

Jeff

[Kristopher Skelton]

Terry, here are the pics, as promised

 

edit: there's a hole in the back about 3/4" x 2" so I can slide longer pieces through as needed.  I use a brick (surprise!) to hold a piece of cerawool over the hole.

[Kristopher Skelton]

Inlet side. . . I wasn't kidding about the bricks!

[Kristopher Skelton]

Ok, the old 50CFM blower ($13 bathroom ceiling fan from the Depot) did not get the forge to yellow hot as this picture would lead you to believe.  My camera has a funny interpretation of color.  I just installed a larger blower and we'll see what happens.  Note the hot spot is about the only place that's hot right then.  Putting the bricks up in the front helps to capture that heat and it's very possible to get a piece hot along the length that's in the forge (for twists on some of my work)