When restoring and painting home exteriors in San Francisco, we often need to replace missing trim or plaster details using casting materials or sculpting clays. A wide range of casting materials can be found at Tap Plastics (tapplastics.com). Scroll down the side-bar to the section labelled “mold-making materials”.
We have re-created plinth blocks and panel “on-lays” using the TAP Silicone RTV mold-making system (Two parts.) A description:
“TAP Silicone RTV Mold-Making System is a complete mold making system that can be used to make virtually any type of mold. TAP Silicone RTV is a two component, tin catalyzed, room temperature cured silicone rubber. It has very low shrinkage, excellent long-term retention of rubber properties and accurate detail reproduction. It is excellent for casting cement, vinyl, wax, plaster, low-melt metals, urethane resins, epoxy resins and polyester resins. It is a safe product to use when directions are followed fully. TAP Silicone has a 6-8 hour demold time allowing two part molds to be completed in one day”.
Once the mold has been made, fill it with TAP “Quick Casting Resin;” A really cool product! Stir the two liquids for a minute or so, then 5 minutes later it catalyzes before your eyes to a hardened plastic!
“A fast curing polyurethane casting resin system that is faster and safer to use than polyesters. It is a two component (Side A and Side B), low viscosity, fast-curing, and non-rising material that produces high-detailed replicas in minutes. Virtually no shrinkage. There is approximately 2 minutes working time. Full cure in 5 to 10 minutes. It cures to a durable ivory finish.
For replicating plaster details and other sculpted items, we recommend TAP “Magic Sculpt”, an epoxy sculpting clay that becomes rock-solid overnight:
“An artist’s alternative to potters’ compounds. Creates extra-fine, highly detailed sculpture projects. A durable two-component epoxy that can be sanded and drilled. Mixed components have a clay consistency with about 1-2 hours of working time. Cures at room temperature to a strong rock hard finish. Also makes an excellent repair putty with tremendous strength and adhesive property. Paint or pigment with color”.
These products are lots of fun to use, so enjoy!
