Fill-It and Fill-It HM are sulfur free clays used by mold makers to seal mold boxes, build dams, set parting lines/shims and repair cracks. They are both off white with excellent adhesive and feathering characteristics. They both are also very flexible and will not dry or crack.
Fill-It is softer than Fill-It HM making it easier to handle at lower temperatures. Fill-It HM is firmer than Fill-It and is less sticky at higher temperatures. The smallest amount of heat, just friction from rubbing it in your hands, will soften both products.
Both Fill-It and Fill-It HM are packaged as one pound blocks, which are scored so that they can be broken into quarter pound sticks.
Both clays adhere well to a variety of materials including aluminum, polypropylene forms, a variety of foams, cardboard and paper. Fill-It products will not oxidize and can be left out or heated and cooled repeatedly without any significant change in the product.
Fill-It and Fill-It – HM are generally used at room temperature. Fill-It – HM is sometimes warmed to a temperature of 105°F - 110°F to soften it. When it returns to room temperature it also returns to the initial firmness.
Fill-It: room temperature to 85°F maximum. Fill-It – HM: room temperature to 100°F.
Wash hands with soap and water after use.
Using small amounts of citrus-based solvents, lighter fluid, latex paint removers, turpentine or mineral spirits as a lubricant on the surface of the clay will help to attain a smooth surface.
Heat over 90°F will cause the original Fill-It to get very soft and sticky and the clay will begin to sweat or sag. The HM formula will tolerate these normal changes.