Casting Mould - how much water

[Zoomie]

I bought a box of letter and number casting moulds and powder from my local 'The Works'.

Just gone to look at the instructions and it doesn't tell me how much water to use. There is 500g of the casting powder.

Can anyone help?

[BucksCM]

Can't tell you exactly how much, but I tend to add some water, mix it, add more if needed and mix it so it's the same consistancy/juat a little softer as butter icing! iykwim?
Easy to get into the mould but not too thick that it doesn't get into the little bits of the mould and not too runny so that it won't set.
There you go...but you're glad I replied!

[sillysausage]

double cream consistency is what I aim for when using plaster of paris.