oven castiing

[roncut]

I have looked around the forum and haven't seen any talk about casting an oven. Anyone ever tried? Any successes?

[david s]

I cast my oven. There is a problem with casting large sections in that the dome is not going to heat evenly, the top is going to get hotter faster than the base, resulting in stresses. It is probably bettter to cast in a few pieces which is really hard for a one off. But even if you do get some cracking the dome is self supporting and won't fall down. The refractory castable is expensive stuff and you should reinforce it with stainless steel needles. Another cheaper option could be crushed fire brick,sand, lime, cement,fireclay 4:3:1:1:1 This should work but I couldn't guarantee it.

[roncut]

I found a place in Texas that sells a product for $75 a 50# of castable with excellent thermal shock resistant. I was thinking of trying to make a pompe that I could move with me from place to place. I wonder how much you would have to buy. How did you make your mold??

[david s]

I made a mould in fibreglass, but for a one off it wouldn't be worth the trouble and expense to do it that way, better to cast over a sand hump. Work out the size of your dome and the thickness of the walls that you want, then calculate the volume required. Find the density of the refractory from the suppiers data to then calculate the mass (no. of bags) required.

[dmun]

I found a place in Texas that sells a product for $75 a 50# of castable

Remember that fifty pounds of masonry material is hardly any at all. Pompeii builders who don't cut their bricks are going to need at least 3 or 4 50 lb bags of refractory mortar to put it together, and most of those domes are brick.

[roncut]

Thanks David and dmun I now have a better view of what to try. I think I will make a fire clay miniature dome and fire it in my oven and see how it does, of course after I cure it.
I like to experiment. I have made a brick pompe I believe it came out well. It has a lot of small cracks in the joints but holds together just fine. I still haven't been able to upload it. My jpegs are to large and I don't know how to upload it to the web and have a link. I am excited about trying a cast oven though. I want to do as much research as possible here so I have a better chance of success.