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DIY fireproof cement

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  • DIY fireproof cement

    (Popular Mechanics, January 1941, page 99)

    "Cement suitable for insulating electrical heating elements and for other purposes where resistance to head is needed, may be made from finely powdered asbestos and water glass. Mix the asbestos and water glass. Mix the asbestos flour with the water glass until the mass becomes thick enough to mold into the desired shape. Pack the cement tight and allow it to dry. When it has become hard and free from moisture, treat the surface with a solution made by dissolving calcium chloride, 1.2 lbs, in water, 1qt. If some finely powered glass is added to the water glass before the asbestos, in the proportions of a pound of glass to a half gallon of water glass, the cement will become extremely hard and impervious after heating. Old bottles and scraps of glass may be powdered readily after heating and dropping into a bucket of cold water. This will shatter the glass so that it can be reduced to a powder with an iron mortar and pestle."

  • #2
    Good way to recycle some of those asbestos siding take offs. Just need a
    ball mill to break them up.
    Reminds me of the '80s ? era Nat Geo photos in Eastern Europe of some poor dude hand packing a big bag (30" x 6') with asbestos fiber dumped on a table output from some background machinery. Photographer must be wishing he hadn't gotten within a mile of the place


    • #3
      fast forward to 2012, go to diy chain, buy large sack of refactory cement (well you can here!) designed for chimney repairs for about double the price of a sack of normal cement


      • #4 about DIY cancerproof cement? :P
        Amount of experience is in direct proportion to the value of broken equipment.


        • #5
          A common refractory home-brew (that's been featured in countless Home Shop Machinist articles) is Portland cement + vermiculite + high-temperature mortar.

          But like Mr. Fluffy says, a bag of real refractory (Mizzou, Presolite, ...) is about $50 for a 55lb bag at any HVAC, building supply (not a big box), or pottery supply store.
          "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."


          • #6
            You may want to read up on vermiculite by going to here:


            • #7
              Or if you look for a boiler service company,many good sized cities will have one,they will have anything you might want in refractory,and usually fairly cheap.
              I just need one more tool,just one!