How to make plaster molds made of jewelry?

1. First prepare a barrel, then put on a plastic bag, add water and gypsum powder. The gypsum powder must be more than water, showing a state of difficulty dissolving.
2. Then prepare the plastic wood partition you want to make the mold, build the partition into the shape you want plastic, and then fill in the west gaps with rubber puree.
3, then wear plastic gloves, and the gypsum powder in the barrel until the gypsum powder shows a sticky paste.
4, then pour the gypsum powder in the plastic tool, pour it evenly, and pour all the barrels.
5, as shown in the figure below, let it stand for half an hour after pouring, and wait until it is completely solidified and then perform the next step.
6. After the gypsum is completely solidified, the plastic mold can be disassembled, because it is connected to the wooden head, you can remove it directly.
7, the final gypsum mold also needs to gently scrape off the rubber puree with a knife to complete.

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The production of gypsum mold
1. Introduction
The invention of ceramics is the pride of our motherland, but in the early days, the production process of ceramics was very backward, and even handed the mud into a blank by hand, the production speed of production, production speed Extremely slow, the product quality is unstable and very rough.
In modern times, especially after liberation, the production process has been greatly improved, and it becomes a mold -making blank, that is, according to the design, use gypsum to make a concave mold (also a small number of convex), and then the pottery will be used for the pottery. Or porcelain soil is placed in this mold for blanking. In this way, one product can be completed in just a few seconds, and the size and shape are exactly the same, and the quality is also guaranteed.
In the mold is a tool that uses specific shapes and sizes to make finished products. It is widely used in various material processing industries, such as sand or die -casting molds used in metal molding casting, forging molds used in metal pressure processing , Cold pressure molds, as well as various molds used for molding ceramics, glass, plastic, etc., we can see that molds have a very important role in industrial production today. It is necessary to understand this aspect. Several simple molds made of gypsum make several works.
2. The nature of gypsum
In production or work, some exactly the same works or products are often required. In order to save it quickly, my ancestors had come up with a kind of in the Spring and Autumn Period and the Warring States Period. A very clever way -use molds for production. Due to the limits of the conditions at the time, they used molds or stone carved molds, cast currencies, such as knife coins and cloth coins.
Meded materials used today to make molds are much more advanced than in the past, mainly metal, as well as resin, wood, rubber, gypsum, etc. This is the easier to process in the middle. The knife and a piece of paper or wood, plus some soapy water as an isolation agent.
In order to master and use gypsum, we must first understand its nature. The gypsum powder is made from ore lyric clock -raw gypsum grinding and roasted. By the time, the countryside in the small county may not be able to buy it, so I had to process it by itself. The processing method is: the raw gypsum is broken with milling, the thinner the better, and then bake it in the pot, fry while burning, and burn to about 800 degrees. Its quality is not ready to buy.
plaster powder, chemically, known as semi -water gypsum or burn gypsum (2CASO4 · H2O), which is heated from naturally existing plaster ore ore ore lyso4 · 2H2O to 150 degrees to 170 degrees. 4 and become it. After the amount of gypsum is mixed with water into a paste, it quickly solidifies, and re-turned into CA-So4 · 2H2O. We use the liquid flowing liquid flowing into solids into solid plasticity, making molds and firing works. The entire reaction process is about 15 minutes, and a certain amount of heat will produce a certain amount of heat. After the solidification, the fastness is poor; if the intensity is needed, put more plaster powder.
Mypsum that has been condensed into solids cannot be used again. The gypsum is condensed from liquid into solids, and there is time limit. It is estimated that the amount of plaster is estimated in advance, how much is it needed.
Mylasm powder and gypsum products have a common feature -strong water absorption. Ceramic factories use this feature to create a grouting molding method to make the body. But this is also a disadvantage of gypsum powder. The storage time should not be too long because the air is more or less a little or less moisture, especially in the rainy days and the yellow plum season, the water in the gypsum powder will increase, and its quality should be poor. This will reduce its solidification and speed up the time when it is condensed. It becomes a hard block for less than a few minutes. In the end, the gypsum will not condense at all.
3. The production of the pentagram mold
The high -strength steel or small knife to process gypsum molds. Their principles are basically the same.
The production method:
① According to the size of the need, on a flat plate, use a mechanical drawing method to draw a pentagram graphic.
② In the center of the pentagram, an erected height of a fine wooden stick is erected.
③ Use sculpture mud or rubber puree to mold a three -dimensional pentagram according to the graphic of the pentagram. When plastic, pay attention to the vertices of the wooden stick and the five edges connected to the five -pointed star. He is a straight line.
④ A hard paper or thin piece of wood or thin wood slices is surrounded by a wall of 1 ~ 2 cm in the pentagram to restrict the gypsum in this range without being wasted without loss. At the same time, the gypsum can be condensed into various shapes of gypsum blocks according to the design requirements.
⑤ Stiring gypsum, generally enamel pots and enamel bowls can be used. Sprinkle the gypsum powder evenly into the water until the gypsum powder and water are basically in the same way. The gypsum powder must be quickly and uniform. After the sprinkler, you must wait for the gypsum powder to absorb all the water before stirring. When stirring, if you use a small bowl, just use two fingers. If you use a basin, use the entire hand to support the five fingers to stir it with exhaustion. The stirring gypsum pulp often floats with some foam on the surface. It must be trying to remove it. Otherwise, the surface of the mold will be left with a foam, which will affect the smoothness of the mold and poured finished products. The next production time can be more abundant and shorten the production time, because the solidification time after plaster powder and water are restricted.
⑥ Pour the stirred gypsum powder and pour into a part of the five -pointed star, let it flow down, without flowing, you can pour some gypsum pulp, or touch it with your fingers, or touch it with your fingers. Make the gypsum paste flood the entire Pentagon, and pay attention not to leave air in the gypsum slurry, and then gently pour the gypsum pulp into the "wall" and be as high as the "wall". You can use plaster alone; if you need to increase its fastness, you can add some cement, but you must use more than 500, and the proportion does not exceed 30 %. Large molds also need to add some coarse wire or steel bars in the middle of the mold. And March to increase the strength and tension of the mold.
⑦ After a quarter of an hour, I feel that the gypsum is a little warm, which means that the chemical response of the gypsum has been completed. , Dig the mud. This mold is completed. It is best to use the mold and then use it, so that the fastness can be further strengthened.
4. Put the pentagram with gypsum
The plaster to pour the works. The gypsum mold must be properly processed. ), Closed on the surface of porous gypsum. When turning over, it is necessary to apply the isolation agent so that the poured gypsum will not be bonded with the mold. The isolation agent has soft soap, ordinary soap, Vaselin, and oil. Vaselin and oil are not good. Essence Vaseline is too thick, which will affect the exquisiteness of the mold. Vaselin's oil is also ashes and dirty, affecting the quality of the work.
The method of soapy water — cut the soap into thin slices, put it in the water to heat and melt.
It, especially new molds or molds that have not been used for a long time, soapy water must be painted at least five or six times until the feel is unusually lubricated to pour it. It can be poured after these preparations are done well.
The method of pouring:
① Pour the stirred gypsum pulp in a small part of the mold first. Because it is liquid, it will flow into a low concave place, so you must use the "enamel" method. Every corner of the mold, including every corner, can be enamed in gypsum slurry.
② Pour the remaining gypsum slurry into the mold. Generally, the small ones are full of the mold, that is, the mold is full; It may not be good. The hollow pouring method also uses "lenient" to slowly condense the mold of gypsum pulp. In this way, the thickness of the gypsum can be about one centimeter. Put a layer of Msis in the inside layer.
③ the corner tip of the Pentagon is very easy to be broken when the mold is released. When pouring, you can put a few thick lead and a layer of hemp to increase the fastness.
④ Wait until the gypsum is completely strong, you can remove the mold, which is the key to success or failure. Although the isolation agent has been coated, the gypsum mold and the pentagram are still very close, and the effect of air pressure is more difficult to get rid of it. Eventually the mold is separated, and finally separate them. At this stage, you must be patient and careful, and you must not be rushed to ask for help, otherwise you may abandon the previous work.
The new molds are generally difficult to remove molds. If you use more times, the release is easier.
5. The method of making simple block mold
The molds mentioned above are relatively simple. We understand the basic knowledge and production methods of some molds through production, as well as the performance of each material. If a complex work needs to be turned over, there are two pieces that cannot be solved. Some may have to divide a few to a dozen or even dozens of dollars, but no matter how many pieces are divided, the principle of its production is still the same. Now introduce a method of making a three or four pieces:
① If it is a pottery pig, if its feet are modified a little, it only needs to be divided into three pieces.
② Pick the line to the place with the designed part of the block. Then fix the two strong threads and use glue on the three heads of the segmentation line. Pick up a few more times of soapy water.
③ Pass the stirred gypsum pulp. The movement must be fast, and the three lines and its lines are not allowed, and the gypsum can be added to about 2 cm.
④ When the plaster is solidified without completely solidifying, the three heads are gently pulled up and divided into three pieces. This must grasp the timing.
⑤ After the gypsum is completely strong, do not remove the mold first, use the knife to repairs the surface of them as flat and smooth as possible, and then paint the secondary soapy water.
⑥ In one -third of the mold, use mud strips to make a circle.
⑦ 2 ~ 3 cm plaster on the mud wall, this is the second module, that is, the mold support. It is best to add lead wires to increase its tension.
⑧ After the plaster is strong, first take off the mold, then take the three pieces inside, and the opposite is just the opposite. At this time Put the block mold in order, so that it becomes a whole without rope bundle. However, because this method does not need to be mortised, it is easy to move to use it, so you must be careful.
The works that can also be developed and created can also be developed and created. You can make some medals and trophies, coated with copper powder outside, golden light, and can make aircraft, ships, car models, etc. with molds.