What is a Sculpture Resin?
Today, with the prosperity of the sculpture industry and its increasing growth and development, the use of resins and of course hardeners and catalysts has also increased. So that currently, sculpting resins are used to make most of the sculptures (statues, Sardis, etc.).
One of the types of resins used in the sculpture industry are unsaturated polyester resins.
At first, polyester resin is in a liquid form with the consistency of jam, but when it is mixed with a hardener, after a while its temperature rises and it turns into a jelly, and then it becomes hard and solid. Of course, the drying time can be reduced by adding a few drops of catalyst. Polyester resin must be baked in an oven to harden.
The amount of use of hardener and catalyst affects its quality, durability and color. Polyester resin is a versatile material that is used for coating, molding and making things and usually together with fiberglass fabrics.
Note: Due to the high stickiness of polyester resin, we must take the inside of the mold flat and use separators inside it. For this, we can use paraffin or film. The film is a liquid that is applied with a brush to the surface of the mold and after drying, it creates a thin nylon-like layer.
Polyester resins have special storage conditions and must be kept in a dark and cool place to have a maximum life (6 months).
Harder in sculpture resin:
The hardeners used in polyester are available in both liquid and paste forms. The paste type is easier to work with, the liquid hardener is the color of water and has a pungent smell.
In general, the amount of hardener used in transparent polyester resins is 2%, but the hardening time can be adjusted by increasing or decreasing the amount of hardener. Polyester resin hardens very slowly in thin layers and the upper part remains sticky. In these cases, the amount of hardener should be increased to 4%.
If the thickness of polyester is high, there is a possibility of cracking, and in this case, the amount of hardener should be selected as 1%. When the mold is plastic and sensitive to heat, the amount of hardener should be reduced. If the amount of hardener exceeds 4%, it will make the polyester very brittle and brittle. In order for polyester to be flexible, the amount of hardener should be 1%.
Accelerator material in sculpture resin (catalyst):
The accelerator is a purple liquid that is a cobalt compound. The amount of accelerator has an effect on the color and time of polyester curing. Many accelerators advance the setting time and cause the polyester to turn yellow or red. The material of acceleration of the handle also affects the generation of heat during closing. When the accelerator is more, more heat is produced due to the acceleration of the polymerization process. To prepare the polyester, first pour the accelerator and mix it well, and then add the hardener.
Polyester resin contraction rate:
Different polyester resins usually lose between 3 and 5% of their volume during coagulation (closing). This property has advantages and disadvantages. Its advantage is that due to shrinking, it comes out of the mold more easily. Its disadvantage is that if we pour one layer of it on another layer that has coagulated, due to the fact that the previous layer has distanced itself from the wall of the mold due to shrinkage, it will enter the space and the volume It creates a surplus that must be shaved later.
Painting Polyester Sculptures:
Sculptures made of polyester resins can be painted in two different ways.
The first method: at the very beginning, the liquid polyester resin is mixed with paint and stirred, and then cobalt is added to it, in this way, a uniform color sculpture is obtained.
The second method: after forming and creating a mold of the polyester sculpture, the model can be painted with ink or car colors. Another color that can be used for polyester sculpture is alkyd color.