Plaster of Paris is formed from gypsum. The gypsum is heated to 150 decrees Celsius and becomes a dry powder. When this powder is mixed with water it re-forms into a paste and eventually hardens into a solid. The powder mixed with water is held together by hydrogen bonds in the water molecules. This is a week bond that is easily broken. When Plaster of Paris and water are mixed together they undergo a chemical change. The particles rearrange to make a completely new substance. When plaster of Paris and water are mixed together the mixture becomes warm releasing energy in the form of heat therefore undergoing a chemical change.
You get weak, wimpy Elmer's glue.
You get warm, weak glue.
Saturated water is water that's passed its boiling point yet hasn't evaporated yet. When putting ice water within this boiling-hot water, the heat energy from the boiling water transfers rapidly into the ice water, mixing the two and rapidly changing temperatures.
Mix fresh water and salt water
The wet mix has moisture in addition to the components that have been used. The dry mix only has the individual components with no moisture or water.
If you asking about plaster of Paris which is used for modling, moulds or casting a broken arm then water is all you add to the powder, if it's plaster for a wall in your house then the answer is the same water.
When you mix plaster and vinegar, a chemical reaction occurs that causes the plaster to dissolve and break down. This results in the formation of calcium acetate and water. The plaster will lose its hardness and structural integrity as it dissolves in the vinegar solution.
No, adding dirty water to mix Kal-Kote plaster can negatively affect the final quality and appearance of the plaster. It is recommended to use clean, potable water to mix the plaster for best results.
To make a plaster of Paris mold of a hand, first create a container into which you can place your hand. Mix the plaster of Paris according to the package instructions and pour it into the container, then press your hand gently into the plaster before it sets. Once the plaster has hardened, carefully remove your hand and the mold is ready.
When dirty water is mixed with plaster, it can affect the setting time and consistency of the plaster. The impurities in the dirty water can weaken the plaster mixture and result in a lower quality finish. It is best to use clean water to ensure the plaster sets properly and maintains its strength.
Gypsum The gypsum is heated to about 1500C to remove its H2O (water) content. It becomes a dry powder, with the chemical name gympsum hemihydrate or, more accurately calcium sulfate hemihydrate. CaSO4.1/2H2O
How to make ready mix plaster?
To make a cast at home, you will need plaster of Paris, water, a mixing bowl, and a mold of the body part you want to cast. Mix the plaster of Paris with water according to the instructions on the package until it forms a smooth paste. Pour the mixture into the mold and let it dry completely. Once dry, carefully remove the cast from the mold and it will be ready to use.
The main mineral found in Plaster of Paris (POP) is gypsum. Chemically, gypsum is known as calcium sulfate dihydrate (CaSO₄•2H₂O). When you heat gypsum, it loses water and becomes calcium sulfate hemihydrate—which is what we call POP. Once you mix it with water again, it hardens quickly and is used for ceilings, walls, and decorative work. If you're working on interiors, you might also look into gypsum plaster, which is similar to POP but offers better strength and finish. Brands like Buildwell provide high-quality gypsum plaster products in India, and they’re widely used in modern construction. You can get full product details here: buildwell.in
Get a mould and plaster. Pour water into the plaster and mix. Pour the plaster into the mould and wait for it to dry. Once it is dry carefully take the plaster out of the mould and paint. Note:To get air bubbles out of the wet plaster, gently hit the mould.
some people told me to put pva glue to the mix
"I think vinegar is supposed to work.Lawren1The CRC Handbook of Chemistry and Physics (65th ed. Special:Booksources) lists plaster of Paris (calcium sulphate half-hydrate, CaS04.1/2H2O) as soluble in acid, ammonium salts, sodium thiosulphate (Na2S2O3) and glycerin."I am so surprised that so many people on so many forums, obviously don't have a clue about the chemistry of plaster of Paris. I read in so many places things like "uh, try some kind of acid..."So I have a lot of concentrated chemicals on hand and did lots of experiments with all kinds of acids, both dilute and concentrate, under many conditions and determined that none of my dozen or so acids dissolve Plaster of Paris in any way, but sometimes make it harder.The chemicals which dissolved plaster of Paris are on the basic end of the PH scale, not acid. I first had some success with potassium cyanide, but what really worked better than anything is Sodium Bicarbonate. Makes sense. The sodium in baking soda hooks up with sulfur in the plaster, and the carbon hooks up with the calcium in the plaster.TO BEST DISSOLVE PLASTER OF PARIS PLACE IT IN WARM WATER WITH LOTS OF BAKING SODA.Don't use any acids or it will only defeat the process.Now what really amazes me is that the answer is so simple and safe, and surely some people must know it, but it apparently cannot be found on the internet, until now.Or you can chisel it away because it is soft enough to do so.