i was wonderin how long do u need for your plaster to dry..
coz i xperience unwanted results...

- looks dry but still wet
- to dry till it crack
- too brittle sumtimes
- too wet and watery

i hope someone can give me an answer to how much of plaster, how long for it to dry...all that...

Some of the time frame depends on how 'wet' you mix it. If you mix it thin with more water it will take longer.

Basically, I let hydrocal plaster dry overnight before working with it. I may demold it after a few hours.

If it's just ground work, I will let it dry half and hour or so before working with it.

A lot does depend on what I'm doing. If I want tank tracks in it, then I simply test it every 10 minutes or so.

I think the dry time of plaster depends on the type of plaster, the dilution of the mixture and thickness of the plaster block you are casting. In my experiences, adding some talk powder in it makes the dry time less and a few drops of lemon juice prevents the cracks. if you have big cracks on your plaster work,you can fill then with wall spackle.

I have an addition to what our friends had said;
Adding a little bit salt to the mixture or preparing the mixture with warm water shortens the hardening time of plaster.

hmm..i tink its time to do some trial and error kinda thing...thanx anyway guys...

Hi Neighbour,

Just to add to the abovementioned advice, I believe if your plaster cracks it is not due to drying times but rather because it was too diluted. As it dries plaster will shrink slightly and will tend to crack along the area where its weakest and in this case where there was too much water and too little plaster.

If its brittle it is likely that you may have put it a bit too thin in an area which may experience warping or bending especially if your base is just styrofoam alone.

A rough guide for plaster to water ratio is put enough water to get a consistency similar to ice-cream which is just about to melt slightly. Make sure you mix well otherwise you'll get plaster that will be powdery coz it didn't get enough water or too runny because certain parts got too much. The best is to work in small batches and mix again if not enough.

For that kind of mixture, 48 hours for drying should be a safe bet depending how thick you made it.