New forge design

I think you may be missing my point. Hardware cloth is flexible. Once the forge has been fired (rendering the ceramic wool brittle) if
the shell of hardware cloth flexes (like, when it's moved or bumped), the brittle ceramic wool will break and shatter.
Maybe some ceramic wool materials don't get brittle like that, but the ones I've worked with do. Maybe the Satanite or ITC-100 coatings will make the material stronger, but it won't make it less brittle.
In short, it makes sense to use a steel shell for a gas forge.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Not at all. Define flexible. I'ts not as tough as a solid steel shell, say 1/8" thick or better but it's not quite flimsy either. If the wool gets really brittle all the way through AND I bang it around a lot, yeah it could shatter. Nothing in my limited experience tells me that the wool is in any danger of getting that brittle any time soon though and as I said, I didn't build it to last a century - I built it for functionality, convenience of assembly and portability and cost.

Definately NOT "Once" under normal use and maybe ONLY if exceeding the design specs of 2400 degrees. I got a buddy with a torch that gets REALLY hot if he wants to and yeah, he has caused limited brittleness in wool in his experimenting.

By that definition it "makes sense" to never move your forge around.
GA
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bruce, If the wool lining in a forge/furnace gets to a "brittle" stage it means that it has been heated to a point where it is starting to melt/fuse. If this occurs it effectively renders the insulating properties to that of a hard brick, in other words, useless. This will only occur when the blanket material is OVERHEATED. Blanket comes in different heat ratings. If you are running a forge at say 2000?F using 1800?F rated blanket it will begin to fuse and break down, slowly becoming a useless brittle hard shell. I have glassblowing friends that use 2400? blanket (with a thin coat of Satanite or ITC 100) for the roofs of their glass furnaces. These furnaces are typically run at 2200? -2400? constantly for MONTHS at a time with virtually no change in the texture of the blanket.
Glen G.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.