Por-A-Kast is a two-component urethane casting resin. Combine equal-parts (by volume) of the two components to achieve a fast-setting solid cast.Por-A-Kast is ivory in color and pours with the consistency of water. It flows easily into even the finest detail and every nook and cranny of your mold. Once cured, it may be carved, drilled or sanded easily; and can also be painted.
When casting Por-A-Kast into a urethane rubber mold, always remember that you must use a good separator; if you do not, the urethane resin will stick to the urethane rubber. A good silicone release or wax release is absolutely necessary. Also, keep in mind that resins of any kind are hard on urethane rubber molds, and the molds will not last through many castings. If you use a silicone rubber mold, no release is necessary (although some people like to use one anyway.) Also, silicone rubber molds will last through many more castings than will urethane rubber molds. At Pinkhouse Studios we always use our Silicone 10 as our molding material.
You have about two minutes of working time with Por-A-Kast . The material will become very hot as it cures; but unlike polyester resin, no cracking will occur. You can patch or build-up on the surface of your cured casting, with more Por-A-Kast, but the surface of the fresh Por-A-Kast must be sanded first so that the material will adhere to itself. To ensure the best possible bond, sand the surface a little bit before patching. Keep in mind that you don’t have much working time.
Generally, Por-A-Kast may be de-molded in as little as five or ten-minutes after casting into the mold. If, however, you are pouring this material into molds that produce castings as thin as 1/8-inch or 1/16-inch thick, you will have to wait much longer for the castings to cure, since very little exothermic (reactive) heat is generated in thin-sections of the material to accelerate the curing process. In such circumstances, thin sections may be removed from their molds after about twenty minutes, but will probably still remain flexible for quite a while. You may find this to be advantageous on occasion, as the partially cured “flexible” castings will not snap or break, despite their thinness, while being removed from the mold. They may then be re-positioned before hardening-up completely. Thicker castings of the material will not be flexible after about twenty minutes.
Por-A-Kast – 2-Gallon kit…………………………………………… $125.00