Hearth and Dome construction questions

[arevalo53anos]

Asparapani:



In some of my old answers I had explained how to work with vermiculite/cement mixture and percents between them.

If is your intention to use the vermiculite/cement to isolate your dome, your could go as high as 8:1, that is better as isolation.

To do the mix, it will better to mix the vermiculite with the cement when dry, this permit each particle of vermiculite to be surrounded by cement before be wet.

Whit the mixture perfectly homogeneous could be better to shower it with a light stream (more a smooth shower) and mixing at same time, to not “wash” the cement from the vermiculite particles.

Good work.



Luis

[asparapani]

hello all,

Yet another novice question that needs proffesional answering...

Is it possible to use high temp mortor paste,(the one to bond firebricks with) and cast it into a mold instead of refractory concrete?

I plan on making my molds throughout the winter in my heated garage so it will have time to cure. I'm still stuck on the dome mold technology.

cheers

[dmun]

Originally Posted by asparapani

Yet another novice question that needs proffesional answering...

You're right on this - You need a professional answer. Refractory mortar is not made be any wider than a brick joint. There are castable refractory materials that harden at room temperature, but other than a flue transition, no one here has much used them.

You need to talk to a refractory dealer. These places sell to people building serious things like kilns and boilers, and will have access to an applications engineer, who will be able to answer your questions. Refractory materials, even fireplace mortar, is expensive stuff, far more expensive than firebrick, and you don't want to cast up a big dome sector, and find that it's cracking on drying or firing.

[asparapani]

thanks for the profffesional suggestion....

I'll go speak to a refractory specialist