Refractory Mortar Question

[james]

I wish you could skip that part, but the fireclay is the part that is heat resistent in your mortar -- so you need it. I am guessing you have called every brick yard and stone supplier in a 60 mile radius.

If worse comes to worse, we can always send you bags of Refrax via UPS Ground.

James

[TomB]

I am building a oven now and am having trouble finding fire clay to make the morter. I an in north east Texas. Any ideas?

[Alf]

We use LaFarge Fondue or any high alumina cement for casting furnace caps, oven side springer bricks etc for our large bread ovens. I have also used it to repair oven arches and have built complete oven arches with it. When we are doing a quick Forno Bravo oven installation we use high alumina cement for the island hearth and vermiculite insulation to get things going.

There are two drawbacks with refractory cement mortar, that is, it sets up very fast so trying to build a small oven from brick is difficult as you usually have a lot of cutting and experimenting to do with the bricks. The second problem is that the mortar can really stain the bricks during building so your lovely brick dome is stained black and no amount of firing will clean it off.

Alf

[CanuckJim]

Refractory

Or you could use a brick mortar made from LaFarge Fondue, brick sand and water. Fondue is readily available in Canada, but it's not cheap and not easy to work with. It sets quite quickly but takes a week to cure and you must be very careful with small fires at first to make sure it's absolutely dry.

Jim

[Alf]

In a nutshell ?air set? mortars are for thin bed high temperature installations. In other words you use a thin bed of mortar between each brick, we use it in the furnaces under the large bread ovens we build as the furnace runs at a very high temperature when firing. If you use thick beds of mortar shrinkage takes place during drying.

Don?t be mislead by the name ?Air set?, the mortar only sets when heat is applied, i.e. during firing. Personally I wouldn?t use it for oven construction, its to expensive and wont hold the bricks well until fired.

Use James?s Refrax or a mortar made with lime and fireclay.

Alf

[james]

I have heard from builders that some of the wet pre-mixed mortars (in a tub) don't like exposure to moisture, and that you have to be careful in outdoor use. I think you have to be patient and make sure your enclosure is waterproof.

Not to belabor the point, but Refrax from Forno Bravo is made for pizza oven installation. That's its sole goal in life (along with fireplaces). It is a dry premix, works fine outdoors, has a setting agent, and is less expensive than the wet pre-mixed you find in various masonry supply stores. Some refractory mortars take 48-72 hours to cure, but Refrax is 70% set in 70 minutes.

You still have to pay for shipping from California, but it's something to think about.
James

[DrakeRemoray]

The DEMON appears to be an "Air Set" mortar. Here is a link to a different refractory air-set mortar that has a little more info on the page This company does not reccomend Air set for outside installations...I ended up buying http://www.alsey.com/non_water_soluble_mortar.htm
and when I ran out, I bought Heat Stop 50 Dry Mix. These were not cheap either...

Probably want to keep it dry as you can, and then once it is enclosed it would stay dry?
Drake

[Fudugazi]

Im using a refractory Plastic Fireclay Premixed Mortar for Firebrick Called DEMON Mortar Mix made by Plibrico Purchased in a Pail. This stuff seems to take quite a while to set up and then if exposed to moisture the next few days it seems to take up moisture again and become more pliable Does this stuff require higher than normal summer air temps to fully cure? Anyone familiar with this stuff It was purchased from Alsips in Winnipeg the largest brick and refractory place around Quite expensive about $40.00 a pail . Hope its the right Stuff!!!