Polymer resin is a clear liquid plastic product that hardens to create a thick, durable, glossy coating. Once hardened, it is fade-proof and water-resistant. This type of resin is commonly used on furniture to seal finishes and create a durable, glass-like surface, and it's also used in many other arts and crafts when the artist wants a thick, glossy coating.
A liquid plastic resin and a liquid catalyst are the two parts of a polymer resin. The liquid resin is activated by the catalyst, which begins the hardening process. The user mixes the two parts, usually in equal measure, for a certain period of time until they are thoroughly combined. It is normal for the resin to heat up during the mixing process because of the chemical reaction between the resin and the catalyst. Once mixed, the liquid can be poured over the surface that the user wishes to coat. In liquid form, the resin is self-leveling, which means that it flows and forms a level surface as it hardens.
Once the resin is poured, it begins to harden or cure. Curing is the term for the chemical reaction within the resin that allows it to go from a liquid to a solid form. While it's curing, bubbles may form, but they can be removed with heat. For small projects, a hot breath can bring the bubbles to the surface where they will naturally pop. For larger surface areas, running a blowtorch lightly over the top of the resin will heat it enough to allow bubbles to rise.
Depending on the brand, polymer resin can take anywhere from 48 hours to 72 hours to fully cure. While curing, it is a good idea for users to cover their projects so that dust does not fall into the liquid and become trapped, marring the glossy finish. Small projects should not be handled during curing because fingerprints will stay in the resin while it is still soft.
Once the resin has cured completely, it can be cleaned normally using water and some mild soap on a damp cloth. Harsh chemicals or abrasives should not be used to clean the resin after it has hardened because they could damage the surface. Minor scratches on the surface can be rubbed away; the heat of friction causes the scratched resin to melt slightly and flow back into an unbroken surface.