I would forget the mortar idea for securing the blanket to the
shell as it just won't hold, at least not for long. The blanket expands
and contracts and sooner than later it will separate form the shell.
The hangers might work but Tungsten is expensive and how would you
attach it to the steel shell?
Here is a trick I learned from glass blowers who have been playing with
modern refractories long before us smiths. It is a little more work but
in the long run you will have a forge lining that should hold up for
many years. The method is as follows: Instead of using one or two flat
layers of blanket rolled up into the shell, cut the blanket into narrow
strips approx.4" wide x the length of the shell. These strips are then
soaked in water (yes water) then folded in half along the length. Now
compress the strips between boards to make a nice tight fold, most of
the water exits now. Take these folded sections and fit them into your
shell. It is a little awkward and the last couple of strips require
some fudging around but it really is not that much work. As the strips
continue to dry out they expand and self lock themselves in place. Not
only that but depending on how wide you cut your strips you can get a
nice thick layer of insulation. If you want to get real serious about
ultimate durability find a source for collodial silica. This is a water
based suspension of extremely fine silica particles. This is mixed with
the water you use to soak the blanket in. This substance acts as a
stiffener similar to the binders used for making refractory fiber board.
The collodial silica also makes a great base coat if you intend to add a
hard shell layer of refractory to the exposed lining of your forge. This
is a good idea for several reasons not least of which is health related!
A great top coat for the inside of your forge is finely milled
Zirconium mixed with collodial silica. Glassblowers call this mixture
"Z-wash" This coating stabilizes the lining acts as a heat reflective
coating and is fairly resistant to borax flux, (which will eat through
naked blanket like gasoline on styrofoam)!
There are lots more tricks we can learn from glassblowers. A great
source of supplies and information is available from Dudley Gibberson
milled Zirconium, burner heads, blanket etc. He also has a great book
on furnace design. It is geared towards glassblowers but there is a LOT
of data directly related to gas forges. It costs like $35. but it's
Get it HOT, FAST!