Can you make multiple 2-part molds at one time?

Can you make multiple 2-part molds without having to remove the clay and take the walls apart and the clay out? Or do you have to repeat the whole process every time if you want to create more than 1 mold of the same model?

Paige Russell2 months ago

Hi bbailey,

To achieve the best registration results, it is better to make one complete mold at a time.

You will always have to remove the walls in order to get the first half of the mold out (without disturbing the model and sprue/air hole) and if you remove the model from the first half of the mold in order to pour another first half, you will lose the seal between the model and silicone which will result in a small air gap which has the potential to get filled with material from the second half pouring.

To avoid this, you would have to fill it with clay, which is time consuming, and it will become a raised ridge on your finished cast piece.

If you want to make more than one mold, a good time saver is to be very careful when removing the clay from the first half, so you can reuse it with minor touch ups for your second mold.

Another option is to use the first mold to create a 'mother mold' for each half. This means you would make a mold of each half of your two piece mold (think of each half as a new model), so you can cast as many molds as you'd like that way without having to redo the whole mold making process every time. This will require making a multiple part mold for each mold half.

This instructable by alepalan shows you the basics of 3-part mold making:

Let me know if you have any more questions!