Justin Jotso of Jester Productions and FX (Alachua, FL) needed materials to make a replica Captain America helmet from the recent film for a customer. He shared his mold making and casting process with us using Rebound® 40 silicone rubber to make his mold and Free Form® Air Epoxy Putty to make the rigid support shell.
The Rebound® 40 mold was used to make 2 different versions of the helmet - rigid and flexible. The first helmet needed to be rigid and have a paintable surface for display purposes. Justin utilized EpoxAcoat® RED Surface Coat Epoxy that was then laminated using layers of EpoxAmite® 101 FAST Laminating Epoxy and fiberglass. The fully cured helmet was primed and painted. The second helmet needed to be worn as part of a costume and needed to be flexible, durable and paintable. A surface coat of Smooth-Cast® 65D semi-rigid urethane resin was backed up with VytaFlex® 40 urethane rubber to achieve these characteristics.
When asked about his experience with the materials used Justin said, "I'm switching all my molds over to Rebound 40. It works great and the library life is amazing!" For more information, please contact Justin here: http://jesterfx.com/
Smooth-On Products Featured in Step-by-Step Tutorial:
Finished Captain America replica helmet sculpt was made using non-sulfur clay and is ready to be molded.
A brush-on mold will be made using Rebound 40 platinum-cure silicone rubber. The rigid support shell will be made from Free Form Air epoxy putty.
Rebound 40 has a mix ratio of 1A:1B by volume or weight. Part B is dispensed.
Dispense an equal amount of Part A.
Mix Parts A and B thoroughly until there are no color streaks.
A thin coat of rubber is applied to the original model. Use a stippling motion to force liquid rubber into areas of detail.
The first layer of mold rubber is allowed to partially cure. In order for subsequent layers to bond to previous layers, they must be added while the previous layer is partially cured, not fully cured (tacky but not in a liquid state).
For the second layer, measure equal Parts A and B and add SO-Strong Black to color it.
Mix thoroughly until there are no color streaks. Adding a color to every other layer will help distinguish between them.
Apply a thin layer over the partially cured layer.
Completed second layer of rubber. Apply at least 3 - 4 total layers of rubber until the mold walls are at least 3/8 inch in thickness.
Pre-made registration keys are applied to the final layer of rubber. Allow the mold rubber to cure for at least 6 hours.
Before the rigid support shell is created Ease Release 200 release agent must be applied to the cured rubber or anywhere the shell will come into contact with it in order to prevent bonding.
Free Form Air epoxy putty is used to create the 2-part rigid support shell. It has a mix ratio of 1A: 1B by volume.
Equal Parts of A and B are dispensed, mixed and applied to form the first half the support shell. Make sure the support walls are at least 3/8 inch in thickness. Allow to cure for 24 hours.
Thoroughly apply Ease Release 200 on the cured Free Form Air support shell prior to applying the second half of the shell in order to prevent bonding. Allow to cure for 24 hours.
EpoxAcoat RED Surface Coat Epoxy is used to make the surface finish for the rigid helmet casting. EpoxAcoat RED is mixed by weight 100A : 15B (can also be mixed by volume). Part A is dispensed.
EpoxAcoat RED Part B is dispensed. Mix both parts together thoroughly.
Apply 2 thin layers of EpoxAcoat RED into the mold. After applying 1 thin layer of epoxy, let partially cure for 1 hour until tacky hard. Apply a second thin layer and again partially cure for 1 hour until tacky hard.
EpoxAcoat RED is allowed to partially cure before EpoxAmite 100 Laminating Resin and reinforcement cloth are laminated over the surface coat.
EpoxAmite 100 is mixed by weight 100A : 24B (can also be mixed by volume). Part A is dispensed.
EpoxAmite 100 FAST part B is dispensed.
Mix both parts together until thoroughly combined.
Detail of the inside of the mold with fiberglass mat and EpoxAmite laminating epoxy applied. Layers are built up until a final casting thickness of 1/8 inch is achieved.
Helmet casting is demolded and is ready for the flashing to be trimmed.
The flashing has been trimmed and the surface is ready to be primed and painted.
"Battle-worn" Captain America helmet reflects perfect detail from the Rebound 25 mold.
Several completed helmets in various positions on display. Rigid fiberglass/epoxy version and flexible versions were made. Flexible version used a surface coat of Smooth-Cast 65D backed with VytaFlex 40.