Q: How are torn molds repaired?

A: ANSWER

You can follow the following 4 steps process to repair torn molds:·

* Roughen the surface with an abrasive such as sandpaper or steel wool. This prepares the surface area for stronger mechanical bonding.

* Clean the surfaces with a good degreasing solvent such as toluene, naphtha, and mineral spirits. Note: acetone and alcohol such as IPA do not provide adequate cleaning. Be sure the solvent has completely evaporated before proceeding!

* Apply the silicone. Because silicone rubber sticks so well to itself, for the strongest patch, it is recommended that you use the same silicone rubber that was used to make the mold. One part silicone acetoxy sealants such as Dow Corning® 732 Sealant also work well as the bonding agent, as they are formulated to strongly adhere to many surfaces, including cured silicones.

* Allow curing. Secure the seam line snugly, matching all surfaces tightly. Wipe off any excess silicone that is squeezed out of the seam. In most cases the mold will be ready to use within 16 to 24 hours.