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slipery bricks

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  • slipery bricks

    OK so my 42" build has been going ok but now that I am getting near the top chains setting the bricks has been very slow. (See the attached photo of the jig I have been using.)
    The problem I have is that I can only set one brick at a time and then have to wait for the mortar to set so the brick does not slip down befor moving on.

    Anyone with ideas of a jig or method to hold the top most chains in place while the mortar sets please send your ideas/photos my way


  • #2
    Re: slipery bricks

    Other than using forms I believe Mike from Saginaw, Mfiore, used three or four quick grip type clamps to hold the bricks in place and once the first was set up enough to remove the clamp.. use it on the next in the chain and so on. I also am told that if you don't soak the bricks the higher you go, they "grip" better. Let me know if it works out for you, I am planning on using this method myself but am not to that stage yet.

    Last edited by KraemerBAC; 10-25-2009, 09:12 PM.
    Member WFO-AMB=WW


    • #3
      Re: slipery bricks

      it looks like you are using the refractory mortar and only applying it to the bases of your bricks initially and then filling the side wedge shapes after the brick is set in position.
      I used the poor man's mortar and cemented the bricks as a brickie does when building a wall, ie, mortar on all adjoining surfaces. My mortar was 1pt portland, 1 pt hydrated lime, 1pt fireclay (which made the mortar much stickier) and 3pts brickie sand. I had no problems with the bricks wanting to slide away until they were almost vertical (the final course only) just prior to the keystones.
      Anyway, check out my build and follow the prompts through it completely for tips, tricks and ideas.
      it also shows how I managed the final few chords.


      Prevention is better than cure, - do it right the first time!

      The more I learn, the more I realise how little I know

      Neillís Pompeiii #1
      Neillís kitchen underway


      • #4
        Re: slipery bricks

        I filled my voids as I went,, If the brick or the mix was too wet some would slide off.. I also had a wood form inside that held about every 4th. or 5th. brick depending on location.. try making your mix just a little bit dryer, also put the mortar on the previous row and tap the brick into it...

        Last edited by ThisOldGarageNJ; 08-16-2010, 05:50 PM.


        • #5
          Re: slipery bricks

          I braced my fire brick using first one method and then evolving towards another.

          My first approach allowed for adjustment, from one brick to another. It was composed of two sticks (whatever is handy) joined by two strong rubber bands (saved from bunches of asparagus and broccoli bought in a local store). Each stick is shorter than the overall length needed. While banded togeather I just extended one piece to get the final length required.

          My next approach used really cheap dowels - about 1/8 inch diameter - cut to the general length. I had old roof shingles covering my floor to catch any mortar drips. Just shuffled those around until the down was at the right position to hold each brick. At one point I had around 10 or 12 dowels in place. These dowels cost around $.88 each and were 4 feet long. Cut down to size I got two usable dowels out of each for my 42" oven.

          I just finished the dome and need to quickly get the "vestibule"/stack ready and apply insulation and then stucco - winter's icy grip is rapidly approaching.


          • #6
            Re: slipery bricks

            I built a low dome oven, so my bricks were pretty steep from the first course... gave me lots of tries to find a solution to this problem. For me a few light taps with a rubber mallet seemed to set the brick in place and they wouldn't slide, but I also used homebrew mortar.


            • #7
              Re: slipery bricks

              I used Heatstop 50 and found that if I didn't have the mortar too wet I was able to build all the way to the top without having to brace anything. As Neill did, I put mortar on the bottom of the brick and on the side facing the previously laid brick. I then tapped it into place with the back of the trowel and held it there until I was satisfied it wasn't going to slide. Generally, I did not use any shims or wedges. When the bricks were close to vertical holding it in place took about a half minute to a minute before I was sure it was going to stay put. I kept thinking that the course I was on would be the last one I could do without bracing with sticks or something, but never needed any bracing. The last 3-4 courses of 1/3 bricks and then 1/4 bricks were lighter and didn't tend to slide as much.


              Member WFOAMBA Wood Fired Oven Amatueur Masons Builders America

              My thread:


              • #8
                Re: slipery bricks

                With the angle you have on the picture you should be able to do 3 (maybe 4) more rings without any support if your mortar has the right consistency. what I do from there on is I cut a circular styrofoam bord at the same diameter as the remaining opening. Support it from inside the oven, up to the opening, and then use wooden shims between the styrofoam plate end the remaining bricks as I close the top. To take it out I just brake it apart.



                • #9
                  Re: slipery bricks my solution - groove the bricks.

                  I had great sucess preventing the downward slide by using my wet saw to apply notches or grooves to the top, bottom and sides of the brick. These grooves
                  seemed to give enought traction and prevented the bricks from sliding.
                  I used homebrew mortor.

                  I applied a taper to each brick so adding grooves took little more time. The grooves are probally 1/4 inch to 1/2 inch deep.

                  The bottom of each brick rested on top the the bricks below it.

                  I'll see if I have any digital pictures.


                  • #10
                    Re: slipery bricks

                    You could always use an angle grinder to cut some grooves into the sides of the bricks to help lock them in. I didn't need to do it during the dome construction, they seemed to stick together just fine (no forms either). But I did cut grooves into the arch bricks...
                    Check out my oven progress here:

                    See ALL of my pictures here:


                    • #11
                      Re: slipery bricks

                      necessity is the mother of invention !!