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Refractory Mortar Question

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  • That's Amore
    replied
    Re: Refractory Mortar Question

    How do I get this refrax mortars from forno bravo I can't seem to find it

    Leave a comment:


  • That's Amore
    replied
    Re: Refractory Mortar Question

    Hy guy's I am new and would like to know if the refmix is exclusive to forno bravo or can I purchase this anywhere. If only at forno bravo how do I go about ordering it. I am building the pomeii 42" and I have the FB board and am just in need of the proper morter

    Thanks

    Leave a comment:


  • james
    replied
    Re: Refractory Mortar Question

    Not many people are mixing their own mortar with Calcium Aluminate (Lumnite), so it is not a big issue, but Balty's posting earlier in this thread on the better mix for lumnite is very useful.

    2 sand
    2 lumnite
    1 clay

    James

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  • Unofornaio
    replied
    Re: Refractory Mortar Question

    Fire Clay does not reach its strength untill FIRED.

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  • asudavew
    replied
    Re: Refractory Mortar Question

    Yes you can buy premixed high temp mortar.

    Here's a link

    http://www.fornobravo.com/store/RefMix-p-16154.html

    Or you can make your own.
    Using:

    1 part cement
    1 part lime
    1 part fire clay
    and
    3 parts sand

    There is also another recipe to make your own. It is supposed to handle higher temps and closely resemble refractory mortar


    1 part calcium aluminate
    1 part lime
    1 part fire clay
    and
    3 parts sand

    Leave a comment:


  • cristaldi
    replied
    Re: Refractory Mortar Question

    Ok, after reading this thread I am confused. Are you all talking about two different mediums for construction?

    One 'make yourself' and Two 'use Refmix'???

    TIA

    Leave a comment:


  • Balty Knowles
    replied
    Re: Refractory Mortar Question

    I called the technical manager at Caluchem today, they manufacture Lumnite. He told me my formula is way too light on the Lumnite he suggested the following mix for my oven mortar

    2 parts sand
    2 parts Lumnite (Aluminum Silicate)
    1 part Fireclay

    Omit the lime altogether, says it has no place in a refractory mortar.

    The lumps in the Aluminum Silicate are very bad, I need to go back to the brickyard & inform him of the problem.

    I will test this formula this weekend & let you know the results.

    Rgds

    Balty

    Leave a comment:


  • Balty Knowles
    replied
    Re: Refractory Mortar Question

    last night I made 2 slugs of high temp mortar & stuck a couple of off cuts together so I could test the strength. After curing for 24 hours I was able to crush the mortar back to powder in my hands.

    This eliminates my thought of over wetting the mortar when I sanded the floor last week & suggests that one of the ingredients is no good. I'm guessing its the Calcium Aluminate.

    Any suggestions, are my ingredients wrong? Otherwise I should I go back to the store to let them know, I'd hate for some poor schmuck to finish an entire project before finding failure.

    Regards

    Balty

    Leave a comment:


  • Balty Knowles
    replied
    Re: Refractory Mortar Question

    I already ripped the 1st layer out & replaced it with Refmix but just as a reference for others. It was still wet after a week, I let a chunk dry overnight & I was able to pulverize it between my fingers the next day.

    Attached is a picture of the bag. Aluminum Silicate, or Luminite. Notice the rocks in the scoop beside the bag. These were sifted out of 1/2 a scoop. Is this normal or could it have gone off in the brickyard. (Old Inventory maybe)

    My formula was 3 dry #2 sand, 1 Calcium Aluminate (I sifted the rocks out), 1 Fire Clay (I think, see pic of bag), 1 Lime. It was measured accurately & dry mixed first.

    I think the problem was that I wet sanded the floor using too much water before the mortar had cured.

    Leave a comment:


  • redbricknick
    replied
    Re: Refractory Mortar Question

    Not sure.. I haven't used al silicate. I use the same formula, but with portland cement in place of the alumina.. Works a treat. I add a little more fireclay to the mix than is prescribed, as it makes the mortar stickier and easier to work with.. Still has nothing on refmix for strength though.. I have some refmix which i have set aside for casting my vent.. Is the name refmix set? How do people feel about it. Any suggestions? Hows about, Fuegofrax, of flament, or refractoment, or cemax, refracto, or... FORNOFRAX?

    Leave a comment:


  • james
    replied
    Re: Refractory Mortar Question

    Wow. Talk about two ships passing in the night. I think the two previous postings were made at just about the same time.

    Glad the Refmix works!
    James

    Leave a comment:


  • james
    replied
    Re: Refractory Mortar Question

    Balty,

    Your floor and first course look great. Now on to the mortar; we want them to stay there for a long time. Can you give us more details on the al silicate that you used?

    Every mortar has to have a setting agent, which is the product that forms a chemical reaction with the aggregate and water to set the final product. You can use Portland cement or Calcium Aluminate (sometimes called the trade name lumite). Without one of these, your mortar won't set.

    Is it possible that your cal silicate was not Calcium Aluminate?
    James

    Leave a comment:


  • Balty Knowles
    replied
    Re: Refractory Mortar Question

    Picked up my Refmix, hard to justfy the cost until you start using it. This stuff is awsome, Spreads like cream cheese, stays open right to the end & sets like a rock. Suggest mixing in small batches unless you know what you're doing. This rookie was able to handle 1/2 bag at a time, approx 12 halfbricks. My only other frame of reference is the high heat formula in the plans, which is very difficult to use, I ripped this out & replaced it with Refmix.

    Leave a comment:


  • Balty Knowles
    replied
    Re: Refractory Mortar Question

    I was unable to get up to Forno Bravo to pick up som Refmix so I got impatient last weekend & set the first couse down using the formula for high temp mortar. 3 sand 1 fire clay, 1 al silicate, 1 lime. It has been 5 days & its still quite soft. I can scratch out the motar with my fingernail.

    Will it set up or should I rip it out? I can think of a few possibilities of what may be wrong

    1 The fire clay says clay mortar on the bag. The brick company assured me it was the same thing.
    2 The aluminum silicate was full of small lumps approx 20% by volume, I sifted them out before dry mixing
    3 I mixed it a little wet because it goes off so fast. It was very difficult to work after about 10 or 15 minutes.
    4 I wet sanded the floor within an hour or so of laying the first course, perhaps it got too wet.

    Any insight on the proporerties of this mortar could save me a couple hours of grief this weekend.

    Any takers?

    Thanks

    Balty

    Leave a comment:


  • TomB
    replied
    You are correct. 200 miles. I have bought two pails of the air set however when I returned, the men laying the bricks thinned it with morter and vermiculite!! I suspect it will have to be rebuilt. If I can figure out how, I will include a picture.

    Leave a comment:

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