Polyurethane is a clear sealant that protects the material underneath from scratches, moisture, and water. But, since polyurethane has no color, can you tint it?
You can tint polyurethane using color pigments. Once it mixes with paint, the polyurethane finish will have a color.
However, the amount of paint you use depends on your needs. So it’s more of a guessing game. If you want a lighter shade of color, you add a small amount of pigments. If you want a deeper color shade, you add more paint.
Changing The Color of Polyurethane
You can change the color of polyurethane by using urethane pigments. Using urethane pigments is the best way to color the change of the sealant. The most common pigments are available in white, black, and blue.
You can mix it with one of these pigments. Or, you can mix it with all three and get a unique shade for your finish.
The urethane pigments come in opaque color as a paste, and these pigments will deliver an opaque finish. You can add 2-4% (based on weight) of urethane pigments to the sealant, mix it, then add a catalyst.
You can tint oil-based polyurethane but you must use pigments (or paints) that are compatible with it. For instance, you can’t tint it with latex paint because they have a different solvent. To tint oil-based polyurethane, use oil-based paint such as enamel or universal pigments.
Oil-based polyurethane tends to yellow over time, so tinting it is recommended as it will prevent it from turning yellow. If you tint it you will have a colorful, thick, glossy finish that protects the wood underneath from weather elements and water.
You can tint water-based polyurethane, but you must use water-based paint or compatible pigments. You can use acrylic or latex paints.
Acrylic and latex paint are water-based that use water as their solvent. Since water-based polyurethane uses the same solvent (water), they are compatible.
However, to get a more colorful finish, use acrylic paint because it has more pigments than most paints. Also, it is more flexible and compatible with polyurethane.
Since acrylic paint is used for artwork, it comes with different colors that you can choose from. This gives you more options in choosing a good color.
How To Tint Polyurethane?
Tinting polyurethane is a great way to create a semi-transparent finish for your material. In addition, you will have a colorful topcoat that protects the material from UV, moisture, and water.
As explained before, there’s no exact formula for doing so, it’s more guesswork; try the mixture on a small surface, and add more paint pigments as you go.
However, here’s a method to follow:
1. Stir The Polyurethane
First, stir polyurethane using a turning stick or paint mixer. Stir for about 5 minutes. Don’t stir too hard, because while stirring, air can trap inside the coating and cause bubbles once dry.
2. Add Paint Pigments.
You must do a test batch first. Try to add a small amount of pigments and see the result.
Pour a small amount of polyurethane into a container; use a measuring cup for accurate calculation. You must write down the exact number of measuring cups you use. This helps you to create a formula to use the next time. For instance, if you want to tint a quarter of it, try tinting three ounces (1/10) first and see the results.
Once the polyurethane is in a container, add drops of pigments (count the drops) and stir the mixture using a turning stick. Stir until the mixture has a consistent color.
3. Test The Tinted Color
Test the tinted polyurethane into a dispensable material. Apply 1 coat of it, wait for it to dry, and check its color shade.
If you want a lighter shade, add more polyurethane to the mixture. If you want a deeper shade, add more pigments to the formula (and mix again).
How To Darken Polyurethane?
You can darken polyurethane by mixing it with dark paint or pigments. Un-tinted polyurethane doesn’t get darker if you add more layers. That’s because it is a clear coat that doesn’t have pigments. So, if you add multiple coats, the finish will get blurry but not darker.
Here’s how to darken it:
- Sand the finish. Sanding removes its glossy layer and allows the new coat to stick better.
- Clean the sanded finish.
- Mix polyurethane with dark pigments. Test the mixture first to see if you like the color shade.
- Apply 2-3 coats of it over the surface. Let each coat dry before adding the next one.
But, don’t apply more than 3 coats as the finish can get blurry.
You can tint polyurethane with any color by using pigments (or paints). Adding color to it is a great way to create a durable colorful finish. However, you must choose the right type of pigments to use.
For oil-based polyurethane, use oil-based paint or universal pigments. For water-based polyurethane, use latex or acrylic paints.