Heat Cast products for build?

[mthomestead]

Hello, I getting ready to order materials for my batch box build. I was planning on using heat cast 40 for the fire chamber and riser, with heat stop 50 as the mortar for the fire brick bell. The skin of my bell will be 3" natural stone and was thinking troweling on thin layer of Insul stick on the outside of the firebrick before I place the stone. Am I on the right track with this materials?
Here are links to the products.

www.mybuildingsupplystore.com/heatcast-40-p/200108.htm

www.mybuildingsupplystore.com/heat-stop-50-p/200103.htm

www.mybuildingsupplystore.com/heat-stop-insul-stick-p/200109.htm
Thanks

[peterberg]

I'd think you are on the right track. It looks like the Heatcast 40 doesn't need to be vibrated.

[mthomestead]

Thanks, I will move ahead with this product and see how it goes.

[econguy]

Hi all,

I have access to the same materials locally, so I am considering using them as well.

Question mostly for Peterberg (I've enjoyed many of your posts): In my application, I would like to cast the walls and roof of the firebox as well as the riser...would you recommend adding perlite to the Heat Cast 50 to reduce the mass of these components? I understand the chance that perlite might melt in in the riser...is that a problem structurally? As far as insulation goes, the remaining air pockets will still provide insulation. As a side note, the Heat Stop product insul-cast appears to be rated to only 2000F...is that sufficient for the riser and/or other components?


Thanks advance.

[peterberg]

Hi Econguy, welcome to the boards.

It's either Heat Cast 40 or Heat Stop 50, Heat Cast 50 isn't mentioned at the site. The Heat Cast 40 is the proper castable refractory as far as I know. Please don't add anything to it, the aluminum cement, being the binder is the most expensive part, its content is precisely what is required in order to get a good bond. When you add something, the bond will be weaker inevitably. The casting will be mildly insulating as it is, density is quite normal what they say at the site. More insulation around it would help, of course.

Most of the time insulating the firebox doesn't add anything, the riser is the part that should be hottest. Perlite will melt when the thing burn two batches back-to-back. It will soften at a temperature around 1600º F, the Heat Cast 40 product is rated 2500º F and that isn't a luxury.

[econguy]

Got it, thanks (I was referring to heat cast 40).

So for the riser, something like 1" thick casting, wrapped in fiber blanket would do the trick?

[peterberg]

Yes, certainly, although I would make those walls a little thicker, something like 1 1/4". That would be difficult enough already to vibrate the thing adequately.

[dcp]

Hello.

Does anybody used Borgcrete 50 as castable for firebox topp and floor?

Information about product available only via producers app: www.hoganasborgestad.com/knowledge/technical-data-sheets/