Advice 1: How to make gypsum

Gypsum is one of the most widely used materials not only in construction but also in the art work, the dental technician, jewelry industry, etc.

The quality of gypsum products is primarily determined by the choice of gypsum powder and the careful observance of technology of preparation of the solution. To make gypsum at home is possible.
How to make gypsum

This material was used in ancient times, before the invention of cars and electricity. Everything you need for cooking is dry plaster and water, the capacity to prepare the solution, a spatula for mixing. It's good to have a fine-mesh sieve (0.2-0.5 mm) for sifting dry plaster before preparing solution. The fresh plaster of good quality, in original packaging pre-screening is not required. For sculpting now available is a large variety of sets, which in addition to gypsum powder includes tools for working with plaster.

The basic requirements for the process of obtaining a plaster solution is the same for all types of plaster and methods of solution — powder pour into water, stirred with a spatula, avoiding formation of air bubbles in the solution. It is possible to pour a thin stream, while simultaneously stirring the solution (this may form a foam on the surface that you want to delete) or to fill the middle of the mound and stir with a spatula cutting movements inside the volume of the liquid without trapping under stirring the air. In an industrial environment to remove air from the solution using vacuum.

Tighten the cooking process is impossible, we must have time to make a cast for 1-2 minutes. The consistency should be the same as heavy cream or liquid cream. Usually 0.7 l of water poured 1 kg of powder. Too liquid solution will reduce product strength, too thick, bad fills in all the corners and meanders form.

The solution is to add dry plaster to obtain the desired consistency, breed the plaster with water is impossible. You also cannot use for solution preparation vessel with the remnants of the previous batch of plaster.

Depending on the brand of plaster mortar hardens over time from 5 to 30 minutes, so you need to mix small portions to be used for a limited time of solidification. Work with a solution in the period from the start of setting until the hardening. Further, the product should be left in a warm room to dry. Reduced temperature affects the quality of gypsum products.

Advice 2 : How to cast plaster molds

From plaster to create sculptures, images, and any forms. The technology of making molds from plaster doesn't cost much and pretty easy. If you learn how to create a plaster form, it is possible to produce any products of various shapes in contrast to mass production. Plaster forms are divided into varieties: a clean, semi-clean and dirty.
How to cast plaster molds
Gypsum is sold in any hardware store, sometimes the plaster can be replaced with white finish putty, but it cures slower. For one of the plaster castings made of rough plaster mold with a soft model, used it only once since her break after drying. To do this form is needed in those cases when there is no need to make products EN masse, or else the product is very complex. Pure forms are used repeatedly for casting of products of cement or gypsum. Semifinished forms removed from the soft models.
Forms of gypsum can be easy, medium and difficult. The manufacture of forms of bulk product or sculpture is no different from conventional molding. Plaster forms are hygroscopic, they should be carefully permeate separation system based on wax or paraffin.
To cast a form of plaster, mix it with water to the consistency of liquid sour cream, pour, wait 10-15 minutes, the plaster will gradually harden. The cured workpiece, remove, remove excess and put in a warm place for a day for final drying. When the blank has dried, remove the excess again, scuff fine sandpaper the entire surface. After that, take a stain for wood, mix it with water and dip it in the finished product for 10 minutes, then remove the workpiece and allow it to dry a bit.
A damp cloth wipe all the convex part, the end result is that all exposed parts will acquire a lighter shade. If the capacity is not large enough to be able to put there the product of the billet cover the stain with a brush.
Producing hollow product, a solution of plaster make more liquid, the form in plaster casts and don't let go for 15 minutes. The form needs to shake all the time in order for the plaster went on the walls evenly and freeze. In the manufacture of decorative tiles for interior design, gypsum should be given more firmness by adding to the composition a little slaked lime. After the molded form has dried, it is impregnated with a solution of sulfate salts.
Slow setting gypsum mortar, you can use the introduction in solution of bone glue or plasticizer
Useful advice
If plaster to give a greater hardness, the finished product will look like made of plastic.

Advice 3 : How to make gypsum

Gypsum is widely used - both in construction and for domestic use. The plaster is convenient to use for various craft projects, handmade, modeling of his sculptures.
Breeding gyps
Plaster represents white with a grey white powder. Gray with the addition of water to the forefront. The cast differs in the degree of grinding: there are plaster fine, medium and coarse grinding. The articles of gypsum of high strength and light weight, but there are drawbacks. The rate of solidification is very high. That is why you need to know exactly how to dissolve the gypsum, because the time to dilute and to add something will remain, the raw material hardens. The plaster is not too much to mix while it hardens faster. Mix the plaster in small portions, and the master only a few minutes in order to knead the composition and to apply it in the case.
Used for any of the works of mark plaster requires special cultivation, in which the powder is added water, and the powder poured in the water. Capacity for cultivation of plaster must be such that with success and then to scrape it from the walls. Good fit, plastic and metal crockery. The proportions of breeding usually make up one part water to two parts powder. Powder poured in the water slowly spreading over the entire area and slowly stir until then, until the water is completely impregnated with the powder. Then 2-3 minutes the solution should stand and thicken without stirring. A sign that the plaster you use - the solution has thickened slightly and is heated. After the powder is soaked with water and started to thicken, add the components in a solution is impossible. Such a solution will be ruined, as the astringent characteristics it will be low.
High speed curing - lack of a mixture of plaster, was invented a few ways of dealing with it. First and foremost is the trade gipsokleevoj mastic. The proportions are - in a bucket of water add 15 g joiner's glue. You can take the PVA glue. To prepare water glue mix thoroughly, and only then poured the plaster. Finally set the mixture begins approximately 20 minutes after its preparation, which is sufficient for different kinds of preparations and bug fixes. In this embodiment, the cooking is valid the same rule is not to add any components later. If the proportion of the solution obtained absolutely will not fit, it is better to throw it away and start again.
In order to slow down the hardening, add citric or tartaric acid. The proportions for the lemon - 0,1-0,2% by weight of gypsum. Acid is first mixed with water, then add gypsum. In those cases, if necessary, however, to reduce the setting time of gypsum in water to prepare a solution is added, stirring thoroughly, salt.
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