How can I add color to liquid rubber or liquid plastics?

Article courtesy of Smooth-On, Inc.

SO-Strong™ liquid urethane colorants can be added to any Smooth-On liquid urethane rubber, urethane plastic for urethane foam (do not use with Smooth-On silicones). They can be used to create a variety of color effects for a wide range of material applications. For glowing fluorescent color effects, use Ignite colorants.

You can add color to almost any material by using a color tint or pigment. Not all color tints or pigments are compatible with all materials.

Coloring Urethane Resin, Urethane Rubber, Urethane Foam or Epoxies

You want to use SO-Strong, UVO or Ignite with urethane or epoxy based materials.

SO-Strong, UVO and Ignite colorants are highly concentrated, offer excellent dispersion and consistent color. A very small amount will color a proportionally large amount of liquid urethane or epoxy material. The more you add in proportion to the volume of liquid urethane or epoxy, the more dramatic the color effect. Recommended loading range is 0.01% to 3.00% of total system weight.

Do not overload the liquid urethane or epoxy material or cure inhibition / oozing may occur.

Coloring Silicones

Color silicones with silicone colors only (use only Silc Pig or Silc Pig Electric). Silc Pig pigments are concentrated, so a little goes a long way when coloring Smooth-On silicone products. Recommended loading range is 0.01% to 3.00% of total silicone system weight.

Do not overload silicone rubber with colorant or cure inhibition may occur.

Pre-mix Silc Pig colorant in container thoroughly before dispensing as settling may have occurred.

Using Colorants

Using incompatible coloring systems may result in the material not curing. If this is your first time adding color to a resin, rubber, or foam, it is recommended that you test the color effect by adding a few drops to a small amount of material and observe the outcome.

Start with small percentages of tint or pigment; you can always add more. Thoroughly pre-mix tint or pigment with Part A or B of the resin or rubber system before combining Parts.

Disclaimer

This FAQ article is offered as a guideline and offers possible solutions to problems encountered during mold making and casting. No warranty is implied and it is up to the end user to determine suitability for any specific application. Always refer to the provided Technical Bulletins (TB) & Safety Data Sheets (SDS) before using any material. A small scale test is suggested to determine suitability of any recommendation before trying on a larger scale for any application.

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