mixture for plaster of paris

The 'correct' way (Dental training!!) is to add the plaster to the water..NOT the other way round...

Coloured water with dies or as Ian told you with tea is OK but DO NOT use paint as it acts to speed up the seting time .(you can use it if you wish but dont mix too much at once)

Add the plaster by sprinkling it onto the water ...keep doing this untill the surface plaster has a very thin dry surface...leave for 1 min then mix by folding the mix together...

To Slow the set you can use Ice cold water or a tiny bit of washing up liquid...

To SPEED up the set time add a pintch of salt to the water before you add the plaster..

There is no ratio that is correct...it depends on the way the plaster was made and its quality.


Alasdair

Hi , when mixing up Plaster of Paris , use pre coloured water , the best comes from an old tea bag soaked for few days in a cup , then cut open the bag mix into the water and plaster of paris. This prevents the dreaded white edges if you chip it later on . cheers ian

Mine says 2 parts plaster to 1 part water. this mix can be adjusted a little if needed.

I thought it was 50/50 but I could be wrong.
Ryan