Steve Shelton

The metal rod I used was salvaged from a section of cattle panel fence.   They were about 1/4" thick or possibly less.   The final thickness of the roof pieces should be 2" or more.   Imbed the rods in the middle of that 2" thickness.

I suggest you test whatever mixture you come up with prior to your final pour.    I went through many component variations before settling on the formula that I used.   What you are thinking about trying might be better or it might be worse.    The testing process was very time consuming.    

A few suggestions:
- make the roof of your firebox several inches thick.  Geopolymer needs to be cured by fire to reach full tensile strength.
- metal rods can be imbedded into the geopolymer to help with spanning the roof section until the geopolymer is fully cured.
- geopolymer can be easily cut after the initial drying phase.  The riser can be made from dry flat sheets that are angle-cut to make the octagon riser.
- the 2 angled floor pieces can be made in the same manner.
- when possible, smaller pieces are easier to work with.  Sometimes this is not an option.
- you can make flat molds, once dried, can be cut into the smaller pieces for assembly.   The dried pieces can be cut into precise sizes.  
- there is considerable shrinkage in the initial drying phase.

Keep me posted on your progress.  

Is there someplace I can see your design?

Yes it has held up well.  I have a fire going as I type this reply.

They are ISA Browns

There is very little waste and no signs of rats or mice.  

Yes, I am free feeding.  

I've got 7 hens and a rooster in about a quarter acre paddock.  It has an abundance of plant growth for them to feed upon.  During the winter months they go through about 5 gallons of feed a week.  I was hoping that the new paddock would all but eliminate the feed consumption during the growing season.  

Unfortunately, it has not.  They still consume about 3 gallons of feed a week.  

Any suggestions?

Annie Collins wrote:

Glen Thomson wrote:I think the better name is HEWS heater, for High Efficiency Wood System. Or for fun, call it a Super Hughey system.

This is my favorite so far. It's short, simple, and quickly tells what it is. I would just maybe add "burning" to it so that it becomes High Efficiency Wood-burning System. And HEWS is easy to say as well as remember, too.

HEWH - High-Efficiency Wood Heater