Bubble Free Molds & Castings | De-airing Rubber and Reisn

Eliminating air bubbles in mold making and casting materials is important as air bubbles are unsightly and not only deface finished surfaces, they also weaken molds and castings. Novice mold makers learn that air bubbles can be reduced by taking technical precautions such as pouring in a high and narrow stream into one stationary spot. Then by knocking the sides of the mold, to cause vibrations in the liquid more trapped air is released. These simple techniques go a long way in bubble reduction. But unfortunately they don’t eliminate them entirely and bubbles caused by air traps usually cannot be eliminated with these techniques.
However, there are several pieces or equipment available to mold makers that will eliminate air bubbles completely. The first one is the vacuum chamber and vacuum pump. The vacuum chamber is primarily used to eliminate air from mold and casting rubbers. Though a vacuum chamber can de-air resins, because many resins set very quickly, often vacuum chamber does not have time to fully de-air fast cure materials that cure to a hard surface.
For that purpose, a pressure pot is used. The mold is placed into the air tight chamber and pressure is applied using a compressor. This method doesn’t actually eliminate bubbles, but simply reduces the bubbles to a microscopic size so that they could not be seen with the naked eye. Thus, if a pressure pot was used to remove air from a rubber material, once the material is removed from the pot and is exposed to normal atmospheric pressure, the bubbles would return as the rubber expands. So a pressure pot is only useful for rigid-curing materials such as clear casting resins as these castings will cure water clear without air bubbles to be seen.
There is a third piece of equipment that a mold making studio should consider - the vibrating table. Though it doesn’t completely remove the appearance of bubble that a vacuum chamber or pressure pot does, it significantly reduces their appearance. And it is less expensive, too. The vibrations created by the table lower the coefficient friction in the mold making or casting liquid to allow air an easier escape to the surface.
Whichever tool you chose, you can be certain that adding a vacuum chamber or pressure pot to your studio will greatly enhance the appearance and quality of your molds and castings.

Видео Bubble Free Molds & Castings | De-airing Rubber and Reisn канала EnvironMolds/ ArtMolds Mold Making & Casting Materials