segmenting the cast (Modular)

[sonomacast]

I have now cut most of the forms for my newest oven project. In order to make things easier and also make the mold re-usable for future castings I plan to segment the oven, No -probs.
My question is this, Most of the modular ovens I see for sale are segmented also at the top. (A kind of key-stone(Round)). Is there a reason for this, does it make the segments more secure and stronger or what? Thank you

[TapRackFire]

Great question. I am about to start casting an oven and would like to know the same thing.

[mrchipster]

Just looking at it from a basic structural issue, you have 3 or more segments converging on a single point and they are constructed of a fairly brittle material. These points would be very susceptible to damage.

From the view of assembly of the multiple pieces the last piece would be almost impossible to fit into it's spot as the keys (think tongue and groove ) would prevent access at the points. Assembly is much easier on a keystone approach as it would just drop in to it's recess.

Chip

[TapRackFire]

Chip,

Is there anything wrong with one solid pour? I have seen some guys on this site pour the walls and then the roof/dome. Anything better or worse with this plan?

[mrchipster]

Originally Posted by TapRackFire

Chip,

Is there anything wrong with one solid pour? I have seen some guys on this site pour the walls and then the roof/dome. Anything better or worse with this plan?

I thought this was a reusable casting???

How big a mold are you wiling to lug around and will it fit into and out of every area you want to use it? Remember the boat in the basement story?

I have never made a pour of this size and someone else will need to chime in.

Chip

[TapRackFire]

Chip,

I'm considering a dome about 40-46 inches in diameter. I have no idea what the weight would be. I guess it could be necessary to pour it in sections if it got to heavy.

[david s]

If you cast it in situ then there is no need to do any lifting.

[waynespizzaworld]

Hi Sonamacast, good to hear you are casting an oven. I am as well in the planning stages of tackling a cast oven or two. Are you posting pictures of the mold making etc that you have done to date?

[mrchipster]

Originally Posted by TapRackFire

Chip,

I'm considering a dome about 40-46 inches in diameter. I have no idea what the weight would be. I guess it could be necessary to pour it in sections if it got to heavy.

There are a lot of variables here Thickness of dome, height, separate or integrated arch and flue. and it will weigh more when wet than after it dries.

You will need to calculate the volume and multiply by density, easiest way is to think of the various parts as spheres and cylinders and subtract the air from the material to get the remaining volume.

Chip

[david s]

4/3pi x rxrxr

A. Calculate inside volume (remember it is half a sphere)
B. Decide how thick you want the dome and add this to r.then calculate this volume (half a sphere again)

B - A = volume of your dome. The bit missing from your door should be approx. equal to the extra needed to bring the dome entry up to vertical wher it makes the seal for the door.

Density = Mass x Volume (use this to work out the mass) From memory the castable density is around 1.8 but check the specs of the product you get. You need a dense castable not an insulating one.