new videos
hot off the press!  
    more about rocket
mass heaters here.

more videos from
the PDC here.
  • Post Reply Bookmark Topic Watch Topic
  • New Topic

So I bought 80kg of calcined flint clay...  RSS feed

 
Kent Hendy
Posts: 4
Location: Auckland NZ
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
So I'm currently underway building my rocket powered pizza/cob oven and I managed to buy 80kg of calcined flint clay.
I thought I was buying flint or fire clay that I was going to use for my cob dome, but it turns out I didn't know what "calcined" meant.

For those of you who were like me, it means it has been super heated and turned into pottery and therefore won't react with water.
So I guess it's effectively grog or crushed fire brick.  It has the consistency of fine beach sand.

So now I'm thinking I will just use the clay I dug up from around my house, but should I use this "grog" as the sand in my cob.
Or should I do a mix of sand and grog.

Any thoughts?
 
Glenn Herbert
gardener
Posts: 2180
Location: Upstate NY, zone 5
74
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The grog should work excellently. Mixing with clay to reduce shrinkage and add toughness is exactly what it is made for.
 
Kent Hendy
Posts: 4
Location: Auckland NZ
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
So should I still aim for three/four parts grog to one part clay for the inner dome?
 
Glenn Herbert
gardener
Posts: 2180
Location: Upstate NY, zone 5
74
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
My guess would be that that's right.
 
Did you just should on me? You should read this tiny ad:
Thread Boost feature
https://permies.com/wiki/61482/Thread-Boost-feature
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!