01:19
Faizan
Mold making and casting requires lot of care and caution every step of the way - right from measuring and mixing to pouring and curing. Every procedure has to be carried out carefully in order to achieve the desired results.
Take mixing for instance. Almost every mold making or casting material from plaster and alginate to polyurethane resin, urethane rubber and silicone rubber consist of two components that have to be mixed together prior to use. It could be mixing the powder or liquid with water, catalyst, curing agent or hardener. Whatever be the material, proper mixing is always essential. Else it can create a marbled effect and also affect the curing of the mold/cast.
Following are a few tips on the same:
Right container - You can use any kind of cups, bottles, cans or other containers made of plastic, metal or glass for mixing the materials. The container used should always have straight sides and bottom. Also ensure that there is no rim or threads on the inside as such.
Right equipment - You need a flat instrument for stirring and mixing the materials. Choose an appropriate-sized paddle for the job. Some people even use craft sticks or paint stirrers as a cheap alternative. Mixing larger batches may require the use of an electric mixer or drill. Irrespective of whatever you use, always hold the equipment at a slight angle (10°-15°)
Right technique - It all boils down to how you actually mix the materials together. A circular motion works best as beating the mixture up and down will trap those dreaded air bubbles in the mix! Always use a firm hand and mix steadily and briskly for at least 2 to 3 minutes. However, being too aggressive can also prove to be detrimental.
Right loosening - Any material will tend to deposit on the sides and corners of the mixing containers. You have to keep scraping the sides and bottom during the mixing process itself to loosen the material that has settled in. Even when using a drill, it is always better to manually scour with a paddle in between. This will ensure a thorough and proper mix.
Some people even go as far as emptying the mixed material into a fresh container before use, so as to avoid using the 'settled in material' that can spoil the mold or cast!
Right deairing - You have to use the material soon after mixing. In fact, some catalysts or hardeners may have a quick cure time, thus necessitating immediate use. However, it is always advisable to let the material rest for a few minutes after mixing. This will allow the air bubbles to rise to the surface that should be broken prior to use. Some simply tap the container to loosen the trapped air in the mix. Alternatively, a vibrating table or vacuum chamber can be used for the job.
Take mixing for instance. Almost every mold making or casting material from plaster and alginate to polyurethane resin, urethane rubber and silicone rubber consist of two components that have to be mixed together prior to use. It could be mixing the powder or liquid with water, catalyst, curing agent or hardener. Whatever be the material, proper mixing is always essential. Else it can create a marbled effect and also affect the curing of the mold/cast.
Following are a few tips on the same:
Right container - You can use any kind of cups, bottles, cans or other containers made of plastic, metal or glass for mixing the materials. The container used should always have straight sides and bottom. Also ensure that there is no rim or threads on the inside as such.
Right equipment - You need a flat instrument for stirring and mixing the materials. Choose an appropriate-sized paddle for the job. Some people even use craft sticks or paint stirrers as a cheap alternative. Mixing larger batches may require the use of an electric mixer or drill. Irrespective of whatever you use, always hold the equipment at a slight angle (10°-15°)
Right technique - It all boils down to how you actually mix the materials together. A circular motion works best as beating the mixture up and down will trap those dreaded air bubbles in the mix! Always use a firm hand and mix steadily and briskly for at least 2 to 3 minutes. However, being too aggressive can also prove to be detrimental.
Right loosening - Any material will tend to deposit on the sides and corners of the mixing containers. You have to keep scraping the sides and bottom during the mixing process itself to loosen the material that has settled in. Even when using a drill, it is always better to manually scour with a paddle in between. This will ensure a thorough and proper mix.
Some people even go as far as emptying the mixed material into a fresh container before use, so as to avoid using the 'settled in material' that can spoil the mold or cast!
Right deairing - You have to use the material soon after mixing. In fact, some catalysts or hardeners may have a quick cure time, thus necessitating immediate use. However, it is always advisable to let the material rest for a few minutes after mixing. This will allow the air bubbles to rise to the surface that should be broken prior to use. Some simply tap the container to loosen the trapped air in the mix. Alternatively, a vibrating table or vacuum chamber can be used for the job.
Posted in: arts
