Hydroshrink is a one-part material that mixes with water. Hydroshrink reduces proportionally as water evaporates out of the cured product. You may use a food dehydrator to speed the shrinkage process or simply leave the casting in a low humidity environment for it to shrink; it produces very accurate reductions of any casting.
Most of our experience with this product has been with shrinking objects with a starting size of approximately 6 inches in diameter. Very large castings may be more difficult to shrink because it will take much longer for the water to evaporate from the Hydroshrink casting. You must monitor the shrinking process until the desired size is achieved. When the desired reduction size has been achieved you will make your new production mold from the reduced Hydroshrink casting.