Dissolve Plaster of Paris


by ninapilapil
Tags: plaster of paris
ninapilapil
ninapilapil is offline
#1
Aug1-10, 09:01 PM
P: 2
My groupmates and I were using plaster of paris for our Arch 10 scale model of a chair. We used a glass casserole for the first trial. Kind of stupid. We covered it with oil before putting in the mixture but when the mixture dried, we couldn't get it out anymore. How can I dissolve plaster of paris?
Phys.Org News Partner Chemistry news on Phys.org
Mantis shrimp stronger than airplanes
MRI sensor that enables long-term monitoring of oxygen levels could aid cancer diagnosis, treatment
The anti-inflammatory factory
chemisttree
chemisttree is offline
#2
Aug1-10, 11:34 PM
Sci Advisor
HW Helper
PF Gold
chemisttree's Avatar
P: 3,725
Water and time will eventually get it out. Acid or sugar will accelerate it somewhat.

You can convert the dihydrate back to the hemihydrate by baking it at 150F for several, perhaps many, hours. It should then crumble easily.
ninapilapil
ninapilapil is offline
#3
Aug2-10, 07:17 AM
P: 2
Quote Quote by chemisttree View Post
Water and time will eventually get it out. Acid or sugar will accelerate it somewhat.

You can convert the dihydrate back to the hemihydrate by baking it at 150F for several, perhaps many, hours. It should then crumble easily.
An estimate of how long?

chemisttree
chemisttree is offline
#4
Aug2-10, 12:38 PM
Sci Advisor
HW Helper
PF Gold
chemisttree's Avatar
P: 3,725

Dissolve Plaster of Paris


Quote Quote by ninapilapil View Post
An estimate of how long?
For the heating step? It should take from 2-4 hours but depending on the maximum cross section the water must traverse on the way out, that could increase significantly... perhaps as much as a day or more.

This article has some information that might be helpful.

This thread also discusses a similar problem.

I like the idea of microwave heating. Heat slow at first and then ramp up the power.


Register to reply

Related Discussions
Acid For Plaster of Paris Chemistry 13
How to dissolve PVC thermoplastic Chemistry 3
How to dissolve Sapphire? Chemistry 7