We’ve had a plaster based replacement powder for almost 5 five years. The recipe is rather complicated. It was developed over a period of two years. It has ok damp strength, good green strength, and is quite strong after baking in the convection oven. When finished, one might infiltrate with CA glue, or thin epoxy, or wax/parafin.
Plaster of Paris – 1000 units
4X Sugar (ultra-fine) – 500 units
Powdered Sugar – 500 units
Polyvinyl Alcohol (PVA/PVoH) – 100 units
Sodium CarboxyMethylCellulose (SCMC) – 100 units
Polyox – 50 units
PVA is a really vast array of products and modifications of base product. Contact a technical rep for a vendor near you to discuss your application.
There are a fair number of different kinds of plaster of paris – common plaster of paris, #1 Pottery Plaster, Drystone Plaster, Duramold Plaster, GardenCast Plaster, Hydrocal Plaster, Ultracal Plaster, and various Dental Plasters. Each plaster has different properties and each requires experimentation.
Methyl cellulose is actually only one of a huge family of materials called cellulose ethers, all of which are based on molecules made from chemically-altered cellulose. There are many different cellulose ethers available, with a dizzying array of molecular weights, solubilities and characteristics. One of our favorites is sodium carboxymethylcellulose, or sodium cmc – it has greater adhesive properties than methyl cellulose and is almost as stable.”
Polyox ™ is a group of water-soluble resins. They are white, free-flowing hydrophilic powders supplied in a wide variety of molecular weight grades, ranging from one hundred thousand to eight million. Polyox has a long history of successful applications in pharmaceutical products, in uses such as controlled release solid dose matrix systems, tablet binding, tablet coatings, transdermal drug delivery systems, and mucosal bioadhesives. PolyOx may serve as a cross-linking agent for SCMC and/or PVA.