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Has anyone here used Plastic Cement for refractory mortar?

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  • Has anyone here used Plastic Cement for refractory mortar?

    I know the general recommendation is 3 parts sand, 1 part lime, 1 part portland, 1 part fireclay, for homebrew mortar.

    I also am given to understand that Plastic Cement is MOSTLY lime and portland cement, pre-mixed (with some other minor additives to make it more spreadable and lightweight).

    I tried researching the general ratios of lime to portland in your typical plastic cement product, but found no answer. I have about 600 pounds of this stuff in my garage and would like to use it for my mortar, but have no idea if it is close to 50/50 lime/portland as suggested in the homebrew mortar ratios or if the other additives would be harmful.

    Has anyone tried it?

  • #2
    Are there any aggregate in it?


    • #3
      Originally posted by Petter View Post
      Are there any aggregate in it?
      In plastic cement?? no. not even sand. As far as I am aware it is a blend of only three things, Portland Cement, Lime, and air-entraining additives. I just don't know the proportions of the mix and whether the additives would be helpful or harmful.

      I plan to use it with sand and fireclay for the homebrew mix but wanted feedback from others.


      • #4
        Ok. That's good. Do you have a data sheet or similar that states any sort of compression strength (with/without aggregate)? If so, compare with data of know blends if you wish to make a serious approach.

        Otherwise, my gut feeling is that it will work fine. Maybe add some lime to it to be on the safe side. Then assume it is a 1:1 mix and just add fireclay and sand.


        • #5
          You really need to find out the proportion of lime to portland cement in the mix as it may not be simply a 50/50 mix of portland and lime.
          Kindled with zeal and fired with passion.


          • #6
            Yes, that would be the safest way.


            • #7
              I pulled a spec sheet for Quikcrete plastic cement and the ratios on the portland was 60 to 80% and lime 20 to 40% then some proprietary ingredients my guess, a plasticizer or acrylic additive. It is mainly used for stucco.
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              • #8
                Thank you everyone. I contacted CalPortland to get information about their formula for their plastic cement. As it turns out, this one didn't have any lime at all. They say their product is intended to be an alternative to other plastic cement products which use lime as a plasticizer. They use some other proprietary additives to plasticize this mix. Therefore, I'm not using it anymore.

                I did use this product for my outer arch but discontinued before getting to my dome.