Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

[david s]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

A recipe I have for castable in kiln building use is 5 parts crushed firebrick to one part calcium aluminate cement. I have used this recipe, but crushing dense firebricks is a lot of work.

[Tscarborough]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Heatstop II is a great mortar, but it is NOT a castable refractory. If someone told you that it was I would look for a different, more knowledgeable source. Heatstop does sell a 40# bag of castable, but it is not the same as HSII.

[Tscarborough]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Here is their website:

Heat Stop - High Temperature Resistent Refractory Mortar

It is called Heatcast 40.

[jgestner]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Thanks guys
The more I get into this, the less I know! Hope that changes sometime fairly soon.
The lack of local vendor knowledge issue seems to be a sore point. I may be trying to build the first WFO in my north central Wisconsin county.

John in Merrill

[jgestner]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Wonderful
I look up HeatStop 40 and the first site I see a price for says "Heat Cast-40
Castable refractory used to form and pour special shapes, hearth or oven dome.
HC40 Heat Cast-40 (40# bag) ................. $51.88 plus $39.00 shipping


HC40 Heat Cast-40 (40# bag) - $90.88"

At this rate I might just go dig my own clay and do a straw mud oven for zero cost solution that might last just more than a year with a lot of babying.

John in Merrill

[Tscarborough]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

You will need more like 5 or 6 bags, so that helps the math.

[Lburou]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Do a google search for Wisconsin Refractories....its easy and fast.

[jgestner]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Hi Gang
I am getting closer, but still in research mode.

I am looking at a product from Empire Refractories for casting my own oven shell. It's called KS-4V Plus and they have it for $41.47 per 55 LB bag. I believe it is an ANH/Harbison Walker product and from the MSDS here is the main ingredients...
Chemical characterization
• Description: Mixture of the substances listed below with nonhazardous additions.
• Components:
1302-93-8 alumina silicate 30-60%
14464-46-1 crystalline silica (cristobalite) 20-30%
1344-28-1 non-fibrous alumina 10-20%
12042-68-1 calcium aluminate 3.3/2A, 3.8/3 10-20%
14808-60-7 crystalline silica (quartz) 0.5-0.9%
organic fibers 0.1-0.5%

Two different refractory supply places that I talked to thought this would be an appropriate material to use. I was wondering if anyone out there has used this formula refractory cement for their WFO builds.

Still looking into the best materials to make the castable form parts but 2 rings of this composite edging might be pretty easy to manage for some cast walls for a pompeii type build. I could see how I could use that for entry arch sections pretty easily also. I have not found my perfect solution for the cast dome form yet.

Thanks for any advise.
John in Merrill

[david s]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

You can't go out and buy alumina silicate or crystalline silica in pure form. They are present in varying quantities in other materials such as silica sand and grog (fired ground up clay) these materials will also contain certain (perhaps undesirable) fluxes, which will vary depending on their source. Making your own brew, like I stated before is extremely difficult and you'll need to do plenty of trial and error before obtaining a workable mix.Even then you'll have no idea how it will stand up to the test of time. Good luck, let me know if you hit on a workable recipe.

[dmun]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Just did a search on the Empire KS4V. It's a castable with all the aggregates in it: You might also look at their KS-4 PLUS. It's rated for a lower temperature and might be more affordable.

[jgestner]

Re: Defining the terms "Cement Fondue" & "Calcium Aluminate Cement"

Hi All
I have kind of hijacked this thread with my own questions and plans. I will try to stay on task here, but follow my ecapades in my own thread on Castable Questions http://www.fornobravo.com/forum/f3/c...ons-15887.html

When I start putting forms and castable mixtures together, I will start a new build thread.

I have found that some in these forums have confusion over castable vocabulary. For instance there are dense castable refractory cements that should be used for casting oven walls, dome/ceilings and sometimes floors. These are usually very strong mixes often suitable enough for electric arc furnaces.
Many of these dense refractory mixes contain as much as 95% alumina formulas. These are the actual thermal mass of your oven. And some can be way more than we need in a wood fired oven.

The other possible refractory castable mixture is a less dense insulating refractory mix, (not to be used for actual oven shell, walls, dome, or floor). This type refractory material can still handle pretty high heats, but is meant to disipate the oven mass heat gradually to the point that the outside of the insulating mass can be touched. This is the same function as the ceramic thermal blanket and a full fill of vermiculite or perlite surrounding the oven can do.

The most surprising thing to me has been that by looking for all of the possible mixtures and sources to determine best strength, thermal needs, and cost, I was able to find a local fireplace/ refractory repair person who had ready stock and reasonably priced sources for all of the WFO castable build materials I might want.

My advise to you all is to ask more than two experts or sources in your area and national manufacturing sources as well. You will almost never get the same answer twice, but all of them will provide a workable solution. With more sources you can make better choices on style, quality, and price. Maybe like me, you'll find that you won't have to ship heavy refractory materials from Texas, Pennsylvania, or California if you look under every stone in your own town or county.

See you all again I hope... I'm off to do some mud experiments.

John in Merrill