I Was Beaten By Big Balls

Описание: Last time I successfully made a one part mold for making the smaller of two prototype spherical speaker enclosures. This time I was so excited to do the same with the larger speaker shell that I made a new model which is nicer than my original one because every detail will be captured by the mold and reproduced in every copy.

After making the new model, I made the mold exactly like I did with the smaller one. I thought I was lucky because I found another clear Christmas tree ornament to serve s a spherical mold box.

Once the new silicone mold had hardened, I took it out of the Christmas ornament and tried to demold my original model. The rubber was about 3/4 inch or about 20mm thick. This was too thick to stretch and release the model. After struggling for a very long time, in desperation, I got a knife and tried cutting away enough rubber to let the remainder stretch enough to get the model out of the mold.

Eventually the mold tore apart. It had been poured in two halves, a lower half and the top half. Other mold rubbers I had used would bond to already hardened parts of a mold as though it was one monolithic block and it was impossible to separate them unless a release agent was used before pouring the second half. So I was surprised to see the sreds of the top half separate from the bottom half of the mold cleanly along the line between the two pours.

After briefly considering repouring the upper half, I abandoned this method in favor of a brushed-on one piece silicone mold with a rigid shell, which will be the topic of the next video.