Hi all,

Sorry if I have missed this but I did a search and could not find the exact answers I'm looking for.

I'm currently planning a cast WFO in Australia, going to use the Homebrew 3:1:1:1 mix and cast over a sand mold.

The dome will be 1040mm internal diameter, 50mm thick, and I have calculated that the volume of the dome will be approx 0.1m3, or 100 liters.

So from here, how do i work out how much of each material i need to purchase?

For example, do I assume that the 100L just gets split evenly into 6 parts, and therefore I need:

50 liters of sand

16.66 liters of hydrated lime

16.66 liters of fireclay

16.66 liters of portland cement

Therefore total = 100L of dry mix. Or do i need to apply some sort of bulking factor etc, say 20% additional?

Lime/clay/cement are available to me in 20kg bags. So to work out how many kg of each i need, i googled the density of each, and came up with the below:

Sand = 1631 kg/m3 * 0.05 = 82 kg

Hydrated Lime = 2210 kg/m3 * 0.017 = 38 kg = 2 bags

Fireclay = 1702 kg/m3 * 0.017 = 29 kg = 2 bags

Portland Cement = 1150 kg/m3 * 0.017 = 20 kg = 1 bag (will purchase an extra as spare)

Total mass of dry mix = 169 kg

Also, i want to add the SS needles (melt extract fibres).

From various sources I believe i need to add 3% by weight of the dry mix.

Therefore I will need 5.1 kg of SS needles for 169kg of dry mix.

Have i got this right?

Thanks!

Sorry if I have missed this but I did a search and could not find the exact answers I'm looking for.

I'm currently planning a cast WFO in Australia, going to use the Homebrew 3:1:1:1 mix and cast over a sand mold.

The dome will be 1040mm internal diameter, 50mm thick, and I have calculated that the volume of the dome will be approx 0.1m3, or 100 liters.

So from here, how do i work out how much of each material i need to purchase?

For example, do I assume that the 100L just gets split evenly into 6 parts, and therefore I need:

50 liters of sand

16.66 liters of hydrated lime

16.66 liters of fireclay

16.66 liters of portland cement

Therefore total = 100L of dry mix. Or do i need to apply some sort of bulking factor etc, say 20% additional?

Lime/clay/cement are available to me in 20kg bags. So to work out how many kg of each i need, i googled the density of each, and came up with the below:

Sand = 1631 kg/m3 * 0.05 = 82 kg

Hydrated Lime = 2210 kg/m3 * 0.017 = 38 kg = 2 bags

Fireclay = 1702 kg/m3 * 0.017 = 29 kg = 2 bags

Portland Cement = 1150 kg/m3 * 0.017 = 20 kg = 1 bag (will purchase an extra as spare)

Total mass of dry mix = 169 kg

Also, i want to add the SS needles (melt extract fibres).

From various sources I believe i need to add 3% by weight of the dry mix.

Therefore I will need 5.1 kg of SS needles for 169kg of dry mix.

Have i got this right?

Thanks!

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