Working with polyurethane can be a challenge, so an effective process is necessary. The best tips to follow before pouring a urethane casting are to choose materials carefully, prepare the right tools, prepare the polyurethane polymer, and to pre-test the casting material. When creating the casting, the best tips are to pour material into the lowest or smallest parts first, avoid adding air or moisture, and remove air from a poured casting.
Urethane is widely used, often for creating models and functional examples of industrial products. There is a range of materials used in urethane casting, to match the numerous applications. For example, soft polyurethane polymers might be used to create a medical model. Depending on the type of casting, certain materials and working conditions might be necessary.
Certain materials usually require certain tools, such as pouring buckets and powered mixers. Checking the manufacturer’s instructions on urethane preparation and necessary tools can help with identifying them. Using certain tools also can ensure effective mixing, because some materials require intense mixing before use while others might require very little. Overall, one of the best tips is to avoid adding air or moisture to all urethane mixtures at all stages of the process.
One of the best tips for urethane casting is to pretest some of the casting material. It is important to let the test urethane casting cure completely before removing it from the mold. With a test mold, it might be possible to identify any air, water or other problems with the casting material. A test casting can provide valuable experience with a particular material in particular conditions.
When pouring urethane material, one of the best tips is to pour into the lowest or most detailed parts of a mold first. This can help keep air from forming inside of the material as a result of the flow. Though it is possible to remove air, it might be easier to avoid adding it in the first place.
Removing air from the casting before allowing it to settle may be one of the best tips for urethane casting. Tapping the mold with a mallet can help remove air, and a vibrating surface might be even more effective. This important finishing step can help avoid air bubbles in the finished piece. When a urethane casting has cured completely, the best tools for removing a mold are usually made of wood or plastic.