To cast or not to cast?

[Wlodek]

Right, a brief report is in order.

I have been acquiring increasing amounts of bricks and collating a list of UK refractories suppliers (more than I thought).

Still thinking about casting the top part of the dome. Thoughts (lose!):

• thickness of the cast - the material will be similar to the firebricks used in the bottom rows of the dome, so do I need the same thickness? This would make the cast half a brick thick, which seems a lot. But if I don't I won't have the same thermal mass as the original
• cracking - will it be liable to cracking due to thermal cycling?
• how think are the Forno Bravo cast ovens? In the photos they look 2-3", which is far less than half a brick
• and also - the top part of the dome would be probably approx. 50cm (20") in diameter - is this not too big as a single cast?
• or should it be cast thinner and additionally rendered from the outside? Would that change anything?
• or am I talking rubbish and I should just follow the plans ... ?

Any advice, experience or suggestions, pretty please?

Best wishes,
W.

[wlively]

Re: To cast or not to cast?

Probably best to read this
http://www.fornobravo.com/forum/f28/...rill-2207.html

and then ask ENZ since he is the only one I have seen do it. Now, I did cast my vent transition and a dome plug (approx 15" in dia and 3" thick). The material I used (KS-4) has held up great and am not worried about cracking at all, but it required a specific heat cure schedule. So you could not use it unless you cast pieces small enough to fit in an oven or had a friend with a very large oven/kiln.