The Best Industrial Polymers
Artists will need polyester and polyurethane resins when it is time for clay modeling and other forms of casting. These resins are good for such work due to their ability to cure and form a hard cast. They will also produce the clearness of glass, and have a high gloss finish after proper sanding and buffing. But one needs to choose which of these two to use. You therefore need to know more about their characteristics.
Polymer resins are not the most expensive of the two. They also rely on catalysts or an accelerator for it to work properly. They on the other hand give off a toxic odor, which forces an artist to wear a protective gas mask as long as they are casting. You also need to work in a properly ventilated studio. You also need to add in some form of reinforcement, preferably fiberglass. You shall also find them developing spider web-like cracks.
Polyester resins will also cure to a crystal clear finish. There is however the danger of them yellowing out with time, when they are struck by UV light. They shall also be malleable for a short time, which needs the artist to work fast. They are too hard to use after ten minutes. They are sometimes difficult to use, due to their high and unpredictable shrinkage rate. IT makes for a good bond between fiberglass fabrics.
Polyurethane resins, on the other hand, are more costly. They are however more versatile. They have found work in rubbers, plastics, inks, medicines, and more. They last longer and resist the effects of chemicals, oils, grease, and abrasion much better. When casting, they will not emit any harmful toxic gases.
They are normally presented as opaque and water clear resins. The casts formulated will display plenty of detail, and will not tear easily. They also make for more choices, when you get the hardest as well as the softest plastics. They are susceptible to forming bubbles, which necessitates treatment in a pressure pot or vacuum chamber. You also need to have special colors to paint on them. This makes its choice of colors more limited than other options.
This material is however highly sensitive to moisture. You need to have the right climate to cure it. If you work in a humid place, you need to invest in a dehumidifier. It is therefore good that they cure faster. You only have to work fast when mixing and pouring it to get good results.
These are the things that make you realize that polyurethane resins are better for general mold making and casting works. They shall make good use in a clay modeling studio. Polyester on the other hand is best for fiberglass fabrications.