Gypsum is used very widely - both in construction and for domestic needs. Gypsum is convenient to use for various crafts, handicrafts, for sculpting sculptures from it.
Instructions
Step 1
Plaster of paris is a white powder with a gray shade. The gray color with the addition of water comes to the fore. Gypsum differs in the degree of grinding: there is gypsum of fine, medium and coarse grinding. Gypsum products have high strength and low weight, but there are also disadvantages. Its solidification rate is very high. That is why you need to know exactly how to properly dilute gypsum, since there will be no time to dilute and add something, the raw material will solidify. The gypsum must not be stirred too much - it will harden even faster. The plaster is kneaded in small portions, and the master has only a few minutes to mix the composition and apply it in practice.
Step 2
Any brand of gypsum used for work requires a special dilution, in which water is not added to the powder, but the powder is poured into the water. The capacity for diluting the gypsum should be such that it can then be successfully scraped off the walls. Plastic and metal containers work well. Dilution proportions are usually one part water to two parts powder. The powder is poured into the water slowly, spreading over the entire area, and slowly stirring until the water completely soaks the powder. Then for 2-3 minutes the solution should stand and thicken without stirring. A sign that gypsum can be used is that the mortar has thickened and slightly warmed up. After the powder is saturated with water and begins to thicken, the components cannot be added to the solution. Such a solution will be spoiled, since its astringent characteristics will be low.
Step 3
A high cure rate is a disadvantage of the gypsum mixture, and several ways have been invented to deal with it. First of all, this is the preparation of gypsum paste. The proportions are as follows - add 15 g of wood glue to a bucket of water. You can take PVA glue. For preparation, the water and glue are thoroughly mixed, and only after that the gypsum is poured. Such a mixture begins to finally set in about 20 minutes after its preparation, which is quite enough for various kinds of preparatory measures and correcting errors. In this cooking option, the same rule applies - do not add any components later than others. If the proportions of the solution turn out to be completely inappropriate, it is better to throw it away and start over.
Step 4
In order to slow down the solidification, add citric or tartaric acid. The proportions for lemon are 0, 1-0, 2% of the weight of the gypsum. The acid is first thoroughly mixed with water, then gypsum is added. In the same cases, if it is necessary, on the contrary, to reduce the hardening time of gypsum, salt is added to the water to prepare the solution, stirring thoroughly.
