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Drystone Casting Media's mineral-based formula also provides an environmentally-sound alternative to resin-based products. It is safe to use because it contains no hazardous chemicals or by-products, has no styrene emissions, and requires no costly environmental controls. In addition, the high-strength formulation produces casts with reduced breakage, excellent compressive strengths, good impact resistance, and enhanced flexural properties. DryStone Casting Media also provides the following features and benefits for improved cast pieces:
Silicone molds can be used with DRYSTONE Casting Media, but are not required. Lower cost material such as latex can be used with excellent results. Standard mechanical mixing and casting equipment and traditional solid casting techniques can also be used to eliminate capital investment in new production equipment. And rotational casting techniques can be used to produce cost effective, hollow casts with the DRYSTONE Casting Media "Hollow" formula. DRYSTONE™ Casting Media Mixing Procedures Successful mixing and use of DRYSTONE™ Casting Media require the following specific standards and procedures. To obtain the full benefit of this product, shop practices and procedures must follow the following recommendations. DRYSTONE Casting Media-To-Water Ratio The recommended ration is 100 lb. of DRYSTONE Casting Media to 18-20 lb. of water. It is vitally important to always weight the water and DRYSTONE Casting Media powder. Variations in the DRYSTONE Casting Media-to-water ratio will affect performance characteristics and physical properties. Water Purity Water used in mixing DRYSTONE Casting Media should be as pure as possible. If water is drinkable, it probably is suitable for the mixing of DRYSTONE Casting Media. In many cases, water for industrial use is taken from contaminated sources and is high in organic impurities that will lengthen the setting time of DRYSTONE Casting Media. These and other contaminates could negatively affect the product and ultimately the finished cast. Water Temperature Variations in water temperature will significantly affect setting time and workability, and can cause difficulty controlling mixing times. The rule of thumb is that cold water retards set and warmer water accelerates set. (Both temperature extremes thicken the mix.) It is highly recommended that the temperature of both the water and the DRYSTONE Casting Media be between 70° and 80° F. Mixing The uniform mixing of DRYSTONE Casting Media is very important in producing casts with maximum strength and hardness since there is a direct relationship between energy input during mixing and strength development of the cast. Changes in mixing procedures will have a great effect on the finished product. An ideal mix is one which the powder particles are completely dispersed in the water to produce a uniform, homogeneous slurry. To mix DRYSTONE Casting Media properly for uniform casts, follow these easy steps:
Depending on actual batch size, adjustments can be made to the mixing cycles. Typically, larger batches may require slightly longer mixing cycles. For best results, use the recommended mixer/mixer motor combination as indicated in the chart below. The mixing shaft should be maintained at an angle 15° from vertical. The shaft should be about half-way between the center and the side of the container. The propeller of JIFFY® mixer should clear the bottom of the container by 1 to 2 inches, forcing the mix downward. Generally only one propeller is necessary, but where this does not provide enough turbulence, use two per shaft or use a larger diameter propeller. Deep all equipment clean to avoid acceleration of the reaction between the water and the DRYSTONE Casting Media. Pouring DRYSTONE Casting Media DRYSTONE Casting Media can be used with most mold materials such as silicone, latex, or urethane-type molds. To prepare the mold, make sure it is clean, then dip the mold or spray it with a suitable mold rinse. Using a steady rate, pour the DRYSTONE Casting Media slurry into one corner of the mold or on the highest point and allow the slurry to rise and seek its own level. To minimize air entrainment, mechanically vibrate or shake the mold or the surface onto which the mold is placed. Pour the mold slightly less than full. Continue to vibrate the molds until no new air bubbles are seen rising. Help draw out trapped air by inserting and withdrawing a spatula, stirring stick, or brush into the DRYSTONE Casting Media slurry. Top off the mold, slightly overfilling. Vibrate once more, then screed the surface smooth. Demold the DRYSTONE Casting Media cast material when it reaches peak heat. To aid in the drying and cooling down process, remove the hardened DRYSTONE Casting Media cast from the mold, or loosen the mold walls and allow air to circulate the cast. DRYSTONE Casting Media products can be decorated approximately 2-4 hours after set time.
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