Shipable core idea

I was listening to Paul Wheaton's recent podcast about shippable cores where he was talking about cutting up stodoor seal rope to mix into refractory cement. It occured to me that this was very much like the fiberglass that I do at my day job. It also occured to me that (at least in a fiberglass application) a woven mat would be stronger.

Have you considered using a high temperature mat like welders use? At the shipyard I work at the welder's shop uses this stuff called refrasil to contain wled splatter. I looked the stuff up and it's high nintysomething percnet silica fibers woven into a cloth. The stuff can get up to 1800 F and still retain it's strength and flexability.

I'm wondering if this could be incorporated into your shippable core like a plaster cast that a doctor would use on a broken bone. I know the temps inside get hotter than that if you're able to forge steel with this thing, but the temps on the ourside of the heat riser shouldn't be as hot. You might be able to use whatever Erica's "mystery goo" is for the inside and then wrap that in one layer of refrasil, then spread more goo and add a layer over that. This is the same thing we do with fiberglass. My only question is if the goo would penetrate into the fibers?

The only bummer is that I haven't been able to find a place that actually sells the stuff (well at least not online). I don't know what it costs but I'm sure it ain't cheap. I'll talk to some of the guys in the weld shop and see if they have some scraps I could get for y'all to play with. Well, if you're interested that is.

I taked to a couple of guys in the welders shop and they said no go on the scraps. Apparently they had a big shop cleanup just before Christmas and threw out their excess material. When I told him about what I wanted to use it for he sugested using a wire mesh on the outside layer of the riser.

The inside would be pure super secret mystery refractory wonder goo to insulate it while there would be an outer layer of something like hardware cloth embeded in the wonder goo. It would act like micro-rebar or maybe something like ferrocement to add some structural strength. Hopefully the temps on the exterior wouldn't be hot enough to melt the steel wire.

Now y'all have got me thinking about this problem and I just might have to try making one myself.

The steel expands and contracts at a different rate from the masonry materials. This will eventually cause cracking in the masonry materials...the opposite of what you want.

I think this is what your looking for.
594 Tillman High Silica Heavy Duty Welding Blanket
I used to work there & am still friends with the people who still do. Feel free to drop my name if you order one (but don't expect a discount : )
Tillman also sells a "Extreme Duty" 36oz instead of 18oz
595 Tillman High Silica Extreme Duty Welding Blanket