Mold Making Guide - Two Part Molding

Two Part Molding

This operation is performed in two stages;
- Molding the model up to the decided parting line
- After curing, casting of the remaining part

Parts of the Mold
1- Plastiline base
2- Model
3- Parting Line
4- Dismantable frame
5- First vulcanized half
6- Positioning pins
7- Vents
8- Pouring hole
 
Mold Preparation (Part 1)
The mold is positioned in the plastiline up to the decided parting line then positioning pins are positioned. RTV is poured and left to cure. After turning the assembly the plastiline base is removed taking care not to move the model.
 
Mold Preparation (Part 2)
A thin coat of vaseline is applied to the first part of the silicone mold to avoid adhesion between the two parts. RTV is poured according to the recommended method for a one-part mold.
 
Reproducing the Model
Pouring holes and vents are made according to the models configuration then the same procedure is used as for a one-part mold.
 
One Part Block Molding
Two Part Block Molding
One Part Skin Molding
Two Part Skin Molding
One Side Impression Molding (Brush Molding)
Two Part Impression Molding (Brush Molding)