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Using Porland/Fireclay cement for a Chiminea?

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  • #31
    Re: Using Porland/Fireclay cement for a Chiminea?

    bringing this old post into light as I'm about to make one of these chimineas but would like to know how yours had weathered please matt.
    any damage or cracks?


    • #32
      Re: Using Porland/Fireclay cement for a Chiminea?


      many sorry for the late reply, I wanted to a 4 page essay about my experiences since and ofcourse if got shelved.

      Yes, it has held up very well. Some colouration from oxidation some light crumbling but nothing major.

      But, that said., I think pretty much anything made of regular cement mix (1 part portland, 2.5 parts builders sand) and chickenwire is going to withstand the occasional backyard BBQ and star gazing night. Reinforced concrete turns out to be pretty strong. Who knew? ;-)

      in short
      yes it held up
      (all 1-2.5 cement mixes will i think)
      I have done many experiements
      making bricks, fireplace, tested a number of mixes and put them through fire and hammer test. (pics)
      my two "refractory" mixes are

      1-1-2 clay-portland-paving sand
      1-1-2- 0.5to1 clay-portland-paving sand-lime putty

      (soak the lime power in water before hand to make putty)

      a practical tip:

      sculpting and pushing the cement in the chickenwire is not that easy, adding lime putty to the mix helps by making it more sticky and plastic.

      use one of my mixes, but don't worry about the strenght if you are not going to make a blazing fire every single day
      if you are going to make a chimenea, make the opening wide, make it shallow and wide, and make the walls dense.

      The Classic Rumford fireplace design has shown that all of the effective heat that humans want from a fire is reflectice, meaning directly looking at the flames and embers.
      To get the walls of the chimenea to heat up and radiate heat, they need to be dense, but the denser they get the more innitial energy and time they need to heat up.

      Thick walls storing heat are efficient in a heater in your house that needs to heat your house all day long, less so for a fire outside that you what heat from immediatly.

      In fact, I am completly hooked on the classic Rumford fireplace design, you might want to google "Rumford fireplace" and read up on Count Rumford (sort of an alternative Benjamin Franklink who bet on the british in the independence war and moved to Europe as a result)

      Here's a my first prototype, it throws of so much heat you can easily bbq in front of it.

      Feel free to ask any more questions. i promise i will just answer in the normal 'i open my mouth and out it comes' way instead of waiting for a War and Peace style reply ;-))

      (or show us a picture if you've made some progress since)

      Good luck!