[TheForge] Strengthening castable refractory

Fri Aug 22 23:30:01 2003

Hi Norm,

Sounds like you came up with a better mix than my first store-bought
attempt.  It's an insulating type with pearlite.  Very very soft.  You can
cut it up with a loose hacksaw blade.

Ed

----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Friday, August 22, 2003 11:35 AM
Subject: [TheForge] Strengthening castable refractory

> I think I read somewhere that castable refractory is reinforced with
> short pieces of stainless steel wire that are put into the mix before
> casting.  I'd call a field rep from the info below and ask them how to
> reinforce the dome.
>
> Everyone probably knows by  now that A.P. Green, North American
> Refractories, and Harbison-Walker are now all owned by some
> European company.  I use the website www.hwr.com that is a great
> site for locating nearest distributor, technical datasheetsl, product
> information, etc.
>
> In the castable forge that I'm still messing with I used Mizzou 3000
> but was interested in reducing its thermal conductivity.  Mizzou has
> a number of 7.4 for thermal conductivity at 2000 degrees and the
> insulating castable (Kastolite 30 LI, for one) has a conductivity of
> 4.4 at the same temperature which I think is quite a bit less but still
> no doubt much greater than an insulating blanket like Durablanket.
> I called a field rep and mentioned that I had heard that people
> make their own insulating refractory by adding perlite and/or
> vermiculite to the Mizzou.  I was surprised that he didn't pooh pooh
> the idea and said that he had heard the same thing and it might be
> worth a try.  Mizzou weighs 140 lbs per cu. ft. and Kastolite weighs
> 90 lbs. per cu. ft. so I just added perlite and vermiculite (I forget the
> proportiions that were recommended to me) until I got about the
> density I wanted (90 lbs per cu. ft).  For all I know both additives
> may just create air space in the mix after the heat gets to them.
>
> What the hell this long post has to do with the subject, I'll never
> know.  But personally, I wouldn't worry too much about damaging
> the castable in a reasonably sized dome unless the forge is
> dropped, etc. Anyone who has a castable forge with the experience
> of it would know much better than I would.
>
> Sorry the post is so long.
>
> Norm Larson
>
>
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