What is silicone rubber used for?
Use this text to provide answers for your most commonly asked questions.
Howdo I mix silicone rubber?
Typically, mix the base and catalyst at the recommended ratio by volume, stirring
thoroughly to ensure uniform curing.
Whatis the typical curing time for silicone rubber?
Curing time varies by product but generally ranges from 4 to 24 hours at room
temperature.
Can silicone rubber cure faster with heat?
Yes, some silicones cure faster with gentle heat, but check the product instructions
to avoid overheating
Whatis the shelf life of silicone rubber?
Unopened silicone rubber typically has a shelf life of 12-24 months; store in a
cool, dry place.
Can silicone rubber be used for food-safe molds?
Some silicones such as BakSil are FDA-approved for food contact, but always verify the specific product’s certification.
How flexible is silicone rubber?
Silicone rubber is highly flexible, allowing it to capture fine details and release
complex shapes easily.
Do I need to use a release agent with silicone rubber molds?
Usually, silicone rubber does not require release agents when casting non-silicone
materials.
Can silicone rubber be painted?
Silicone rubber is challenging to paint directly; special silicone paints or primers are recommended.
How do I clean silicone rubber molds?
Clean molds gently with mild soap and water; avoid harsh chemicals or abrasives.
Can silicone rubber molds be reused?
Yes, silicone molds are durable and reusable many times if cared for properly.
What temperature range can silicone rubber withstand?
Silicone rubber typically withstands -60°F to 400°F (-51°C to 204°C), depending on the formulation.
Is silicone rubber safe to use with resin?
Yes, silicone molds are commonly used for casting resin without sticking.
How do I prevent bubbles in silicone rubber?
Mix slowly to reduce air entrapment and consider vacuum degassing if available.
What are the common mixing ratios for silicone rubber?
Ratios vary, commonly 10:1 or 1:1 by weight or volume, depending on product.
Can silicone rubber cure under water?
Some silicones can cure under water; check product specifications.
How do I store leftover silicone rubber?
Store unused silicone in sealed containers away from heat and moisture.
Can silicone rubber be tinted?
Yes, use silicone-compatible pigments or dyes to color the rubber.
What causes silicone rubber to remain tacky?
Incorrect mixing ratios, incomplete curing, or expired material can cause tackiness.
Can I pour silicone rubber over delicate items?
Yes, silicone’s gentle curing process makes it ideal for delicate objects.
How thick should I apply silicone rubber for a mold?
Usually, 1/4 inch minimum thickness is recommended for strength and durability.
What is the difference between tin and platinum cure silicone?
Tin cure is more affordable but less durable; platinum cure offers higher tear
strength and is hypoallergenic.
Can silicone rubber be used for prosthetics?
Yes, medical-grade silicones are used for prosthetics and special effects.
What safety precautions are needed when handling silicone rubber?
Use gloves and work in a well-ventilated area; avoid contact with eyes and
prolonged skin contact.
How do I fix a silicone mold tear?
Use a silicone adhesive or patch with liquid silicone rubber.
Can silicone rubber be used for concrete casting?
Yes, silicone molds work well for casting concrete and plaster.
What is the Shore hardness of silicone rubber?
It varies from very soft (Shore A 10) to firm (Shore A 40+), depending on
formulation.
How long after mixing should I pour silicone rubber?
Pour soon after mixing to avoid premature curing and bubbles
Can silicone rubber be layered?
Yes, layering is common to build mold thickness or add detail.
What is the best way to remove silicone rubber from a mold?
Gently flex and peel away; avoid sharp tools that can damage the mold.
Does humidity affect silicone rubber curing?
Generally, no, but some products may be affected, check product data sheets.
Can silicone rubber be used outdoors?
Yes, silicone’s UV and weather resistance make it suitable for outdoor use.
Is silicone rubber toxic?
Silicone rubber is generally non-toxic once cured, but uncured components may cause
irritation.
What is the difference between brush-on and pourable silicone?
Brush-on silicones are thicker for coating, pourable silicones flow easily into molds.
How do I prevent silicone rubber from sticking to my mold box?
Use a release agent or line the box with a non-stick material like polyethylene.
Can silicone rubber be used with metal casting?
Silicone molds are generally not suitable for molten metals due to high temperatures.
What is the best temperature for curing silicone rubber?
Room temperature (65-75°F) is ideal for most silicone cures.
Can I add fillers to silicone rubber?
Some fillers can be added to alter properties, but check compatibility.
How do I know if silicone rubber is fully cured?
It will be tack-free, flexible, and have consistent texture throughout.
Can silicone rubber molds be frozen?
Yes, silicone molds tolerate freezing without damage.
How long should I wait between silicone layers?
Wait until the first layer is tacky but not fully cured to ensure good adhesion.
What happens if I mix silicone rubber incorrectly?
The silicone may not cure properly, remain sticky, or have poor mechanical
properties.
Can silicone rubber be recycled?
Silicone is not widely recyclable but can be repurposed or disposed of as non-toxic
waste.
Are there odor concerns with silicone rubber?
Some silicones emit a mild odor during curing that dissipates quickly.
What is the typical pot life of silicone rubber?
Pot life (work time) ranges from a few minutes up to 30 minutes depending on the
formula
How thick can I pour silicone rubber at once?
Pour thickness depends on product, but layers thicker than 1 inch may overheat or
cure unevenly.
Can silicone rubber be used to mold food items?
Yes, food-safe silicones exist specifically for molding chocolate, candy, and other
edible items.
How to prevent silicone rubber from tearing?
Use a thicker mold, reinforce with a support shell, and avoid sharp mold edges.
What tools do I need to work with silicone rubber?
Mixing containers, spatulas, scale or measuring cups, and mold boxes are
commonly used.
Can silicone rubber be used with epoxy resin?
Yes, silicone molds are excellent for casting epoxy resin as the resin does not
stick to silicone.
