The Resin Horse -- What is Resin?
What is Resin?
"Resin" is the common name for a class of casting polymers typically requiring two parts. When the two parts are mixed, they produce a chemical reaction and generate exothermic heat, causing the material to harden and fuse into a solid form. The result is a type of plastic. There are many types of resins available, and new formulations are continually being developed for various uses and applications. The color, strength, pouring viscosity and many other factors vary among formulations. Auto-body putty is one commonly seen form of resin, as well as polyester used for piano casings, airplane wings, and many products are structurally laminated with resins.
How durable are resins?
Resin is generally considered to be long lasting and is not biodegradable. It will not rust, oxidize or decompose as some other materials may do over time and is unaffected by water or normal temperatures. While not as strong, nor malleable as metal, it is generally as strong as and not as brittle as ceramics. Depending upon the exact formulation, resins can be as strong and durable as some of the strongest plastics. Since resin is a relatively new material used as an artistic medium, (compared to long-standing materials such as bronze, stone, and oil-based paints) it isn't known exactly how long the material will last, but its safe to assume it will last lifetimes in any case.
Resin is affected by temperature, and also the material tends to remain slightly flexible after it has cured. Warmer temperatures can cause cured resin to become slightly more flexible than cooler ones. This small amount of residual flexibility is both a an advantage and disadvantage. The advantage is that the resin is less likely to break or shatter (as ceramic would). At the same time, some bending or warping is possible over time if a casting is not adequately reinforced.
Due to the nature of pieces produced in the image of the horse... which means four rather delicate legs holding up a heavier body...the best resins are those with steel rods embedded into the limbs and tails (particularly support limbs, and tails that extend away from the body). Resin horses reinforced this way won't warp under the weight of the piece with time. Large-scale resin horses without such reinforcement can show some leg warping over a relatively short period of time, and may have problems if subjected to warm temperatures. Small-scale pieces may be more fragile in the limbs, but often weigh sufficiently less and aren't as prone to warping.
Metal reinforcement rods are inserted into the mold at the time of casting. Some resins can be retro-fitted with metal rods to stabilize them, but this procedure is best done (if needed) before the sculpture is painted and finished, although it can be done afterwards.
Consequently, the resin sculptures themselves can be expected to last at least a lifetime. Paintjobs applied to the resins are somewhat more fragile, but as with as with any other work of art, proper care and handling will ensure the piece will remain indefinitely .
While the resin casting process allows an artist to make (or have made for them) multiple copies of a sculpture, the process is not speedy in the same way as mass-produced injection-molded plastic items. Due to the nature of the resin itself and the fact it takes time to fully cure, plus the mold materials which 'swell' a bit after each casting, production can be expected to be only a handful of pieces per week in most cases. This is why with some resins for which there is a high demand, you may have to wait a few weeks to a few months to actually receive a copy, because they cannot be produced as quickly as mass-production methods. Of course, the quality and level of detail resin-casting is able to capture allows for much more freedom of expression on behalf of the artist that simply can't be found in mass-produced items at all.
©1999-2002 Rio Rondo