Thoughts on this oven build...

[david s]

Re: Thoughts on this oven build...

David: thank you for being so quick to respond. I don't know if it would really be too much cheaper as I can get 90lb bags of CAC for $18.
Have you worked with both CAC and Fire Clay? If you were to pick one (ease of use and longevity) which would you choose?

Yes, I have used both. The home-brew is easier to use because it does not go off as fast as the home-brew. In hot weather I use chilled water to retard the CAC castable that I use. The home-brew has a much higher rate of shrinkage because of its high proportion of clay, so this may be a problem for you depending on your design. I have no idea about the longevity of the homebrew, but two people I advised three years ago to use it in casting a one piece dome both report successes. If you can get the CAC so cheaply then why not use it. You will still have to mix it with some kind of aggregate and that may cause problems. A proprietary castable uses high temperature aggregates (way in excess of what we need) and if the correct amount of water is added will not shrink.