Safeguards for Mold Making
The common method of reproducing an object begins with making a mold. This is a negative impression that captures all the surface features and even the dimensions of the object. Mold makers use different materials like clay, wax, moulage, polyurethane rubber, latex rubber, silicone rubber, thermoset mold rubber, plaster bandages, etc. to make a suitable clay, wax, plaster or silicone mold.
Following are some of the precautions to be taken while making a mold:
· The choice of mold making material will depend on the type of object, the original material and the choice of casting material as well. Even the dexterity of the mold maker should be taken into account.
· There are various techniques of making a mold. The shape and size of the object, the mold making material as well as the experience of the mold maker should be taken into account. The mold should be made in two or more parts for large sized or unevenly shaped objects.
· The mold making material should be of good quality and purchased from a reliable source. This will influence the quality and precision of the mold.
· The best quality mold making materials can unexpectedly react with the model object or affect it in some manner. Therefore, it is best to perform a small test cure on a hidden area of the object before making an entire mold.
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· The object should be sealed properly by applying a transparent coat of sealer. This will ensure that the mold making material does not seep into the object or snag the mold anywhere. It will make for easier demolding as well.
· Using a release agent is a must for all objects. As silicone rubber does not stick to anything, mold makers usually skip using a release agent. However, the oils from the rubber can end up damaging the object in some manner. Even simple petroleum jelly can work as an effective release agent.
· The mold making material is likely to spill or dribble when applying on the object. Therefore, it is better to protect the work surface and floor with newspaper or rubber sheets. The mold maker will be better off wearing old clothing or protective gear.
· In case of say, a polyurethane rubber mold or silicone mold, the material will come in two parts. These should be taken in the correct proportions and mixed properly.
· Careful application of the mold making material will ensure that all the minor folds or indentations of the object are clearly copied in the mold.
· The working time and set time of the particular mold making material should always be taken into account.
· Demolding should be done slowly and carefully. The mold should be allowed to cure properly even after demolding.
