Description
This semi-rigid urethane casting resin is newly reformulated for enhanced performance.
Smooth-Cast™ 61D features a translucent white appearance and improved physical properties, ensuring safer use as it is mercury-free and phthalate-free.
Its low viscosity minimizes bubble entrapment. Vibrant colors are possible by adding SO-Strong™, UVO™ or Ignite™ colorants.
Good for making impact-resistant prototypes, models, toys, props, climbing holds, etc.
Key Features
- Shore Hardness: 61D
- Mix ratio: 1A:1B by volume
- Working time: 7 minutes
- Demold time: 60 minutes
- Low viscosity for minimal bubble entrapment
- Allows for vibrant colors with SO-Strong™, UVO™, or Ignite™ colorants
- Ideal for impact-resistant prototypes, models, toys, props, and climbing holds
Instructions
Safety:
- Store and use materials in a warm environment at 23°C.
- Products have a limited shelf life; use promptly.
- Liquid urethanes are moisture-sensitive; they absorb atmospheric moisture.
- Mixing tools and containers should be clean and made of metal, glass, or plastic.
- Mix in a well-ventilated area.
- Wear safety glasses, long sleeves, and rubber gloves to minimize contamination risk.
Applying a Release Agent:
- A release agent is necessary for demolding when casting into or over most surfaces.
- Use a mold-specific release agent like Universal™ Mold Release or Mann’s Ease Release™ 200.
- Apply a liberal coat of release agent on all surfaces in contact with the plastic.
- For thorough coverage, brush the release agent with a soft brush, then apply a light mist coating.
- Let the release agent dry for 30 minutes.
- Smooth-On silicone rubber molds typically do not require a release agent unless casting silicone into the mold.
Measuring & Mixing:
- Ensure Parts A and B are at room temperature (23°C).
- Combine equal volumes of Parts A & B in a mixing container.
- Scrape the bottom and sides of the container several times during mixing.
- Do not delay between mixing and pouring.
- Higher mass concentration accelerates gelling and curing.
- Shelf life reduces after opening; use remaining product quickly.
- Replace lids immediately after dispensing to prolong shelf life.
- XTEND-IT™ Dry Gas Blanket can significantly extend shelf life.
Pouring:
- Pour the mixture at the lowest point of the containment field to minimize air entrapment.
For Best Results:
- Use pressure casting by placing the casting assembly in a pressure chamber at 4,2 bar (4,2 kg/cm²) for full cure time.
Curing:
- Ensure room-size ventilation or proximity to a forced air vent.
- Do not inhale fumes; they dissipate quickly with adequate ventilation.
- Castings may be hot and irritate skin immediately after curing; let cool before handling.
- Demold time varies with mass and mold configuration.
- Backfill rotational or hollow castings with rigid foam for reinforcement if exposed to temperatures above 30°C.
Performance:
- Cured castings are semi-rigid, impact-resistant, and resist moisture, mild heat, and solvents.
- They can be primed, painted, or bonded to other surfaces with Urebond or similar adhesives.
- Unpainted castings may discolor with UV exposure.
- Conduct a small test application to ensure suitability for your project.
