Creating mold to cast concrete dome? what kind of concrete?

[trader_joe]

I would like to weld a mold from a steel bowl and add the entryway arch.. owning a welder really does allow you to create things you otherwise would not have been able to... like the bowl shape with the cylindrical arch in one piece... and even adding a flange to bolt two halves together to take them apart to remove the piece...
Then i would weld together a smaller version of the same mold and pour the concrete in the larger one and then sink the smaller dome inside of the larger dome to create the hollow area
the amount that the smaller dome is pressed into the larger would determine the dome thickness.

but anyway heres my main confusion:

I have been hearing about refractory mortar... but is there some kind of refractory concrete for casting a solid peice?

Am i supposed to use the same concrete that is used to make the floor slab? What kind of concrete is that? can i just buy a bag of it? or do i have to mix it??? can i get the liquified stuff instead of having to add water?


I am new to this but correct me if im wrong... is the floor supposed to be:

- regular concrete slab or masonry foundation
- insulation
- refractory slab
- firebrick

??

Can i cast the entire dome, entry arch, and floor in one single mold and then place the fire bricks inside from interior wall to wall? or does the dome have to be an entirely seperate piece and placed on top of the floor?

am i to assume the dome walls shouldnt be placed on top of the fire bricks though?





I have a pallet of red bricks in my yard from another project... but I'm uncomfortable using these... they are all different types of bricks and from different manufacturers...

are the red brick domes (that im seeing all over google images) made from special fire bricks? Or just regular red bricks with refractory mortar... Isn't this asking for problems and cracks?

or are these red bricks simply being used as a finish on top of the insulation layer?

If I cast the entire oven from poured refractory concrete in a mold... do i have to use insulation and then add a finish layer of tile or concrete?

what kind of insulation is commonly used? if i remember correctly isn't it some kind of fiber fabric stuff?


How do i do the finish??? would it just be regular non refractory concrete slapped on and smoothed out to make a smooth finish... and then adding optional tiles or paint??

thanks!

[UtahBeehiver]

I think you should take a look at Forno Bravo e-plans, they are 2-3 bucks to download and will answer many of the general questions you have. Although the plans are not for cast ovens, it talks about mortar, hearth layout, layout of insulation, etc. Then peruse, David S threads, he is our casting expert.

[DTucker1987]

Have you solved it? I am wondering about the same thing. I have some serious problems in my house.. I have recently noticed that my furniture is all covered in mold. I guess it happened because of the high level of humidity inside the house. It looks awful, I need to get rid of it! What should I do? Some of my friends recommended me to contact (link removed by moderator). He told me that it's a very good company, that has only professional workers that really know their job. What do you think about ? Should I call them, or maybe I can get rid of it by myself?

[UtahBeehiver]

The post you sent to is a couple years old.

[Jeffery7K]

Have you solved it? I am wondering about the same thing. I have some serious problems in my house.. I have recently noticed that my furniture is all covered in mold. I guess it happened because of the high level of humidity inside the house. It looks awful, I need to get rid of it! What should I do? Some of my friends recommended me to contact (link removed by moderator). He told me that it's a very good company, that has only professional workers that really know their job. What do you think about ? Should I call them, or maybe I can get rid of it by myself?

Change only one thing. A permanent master cast is required. So make your furniture - sculpt it out of wood or whatever you think is best.

Create a box in which your master can fit (or at least most of it, if it is an exceptionally large piece). Insert a card to divide the mold as needed. Then, using silicone lubricant, lubricate your master, box, and cards (you will need to experiment here). Melt the wax and pour it into the mold you've created.

Allow it to settle. Take apart the box. Take apart the mould. Remove the lube from the wax. You now have wax molds for your piece. Ones that you can easily replicate with your master.