How To Color Epoxy Resin with Paint and Pigment
Epoxy is typically as clear as glass, and many people prefer it that way. Unfortunately, even the best epoxy will tend to yellow over time, and what was once a smooth, glass-like covering becomes unsightly and old-looking. Colored epoxies don't suffer from this yellowing effect, so they tend to age better than clear epoxies.
Colored epoxies can also create stunning works of art that just as functional as they are beautiful. A quick image search for "river table" will show you the kind of visual appeal that colored epoxies can have. Those are far from the only thing you can do, though. You can use colored epoxy to fill in cracks and gaps in an old table, creating a totally unique design. You can also use different colored epoxies, applied at different stages, to create multicolored designs.
Colored epoxies have been used to create furniture pieces that sell for thousands of dollars online, but the truth is that they're dead simple to make and use at home. You can make your own designer furniture for a fraction of the cost.
What you can do with colored epoxy?
River tables are the most common example of what colored epoxy is used for right now. If you love the look of these tables, but don't want to spend the money, you're in luck. River tables are among the easiest colored epoxy projects you can take on. All you need is a wooden table with at least one wooden side (or just a wooden table of you like the color scheme but don't care about the river effect).
What you'll do is mix up a batch of blue epoxy, and apply it to the center of the table. You can create a perfectly straight line of blue if you want by using small pieces of wood or plastic to line the center of the table. If you want a more irregular design, often called a live edge, you'll need irregular slabs of wood. In these case, the colored epoxy is both decorative and an adhesive to hold the wood together.
Colored epoxy can also be used to decorate stainless steel tumblers, create a unique finish on a counter top or table, and to create works of art to hang on the wall. It's most common use is as a way use irregularly shaped pieces of wood as decoration. It fills in the gaps nicely and creates entirely unique works of art. It can be used anywhere you would use clear epoxy, though.
Using colored instead of clear epoxy prevents yellowing in the epoxy coat. Yellowing occurs over time with clear epoxy, and it doesn't look good. Colored epoxy ages much better than clear epoxy.
How to add pigment to your epoxy
Adding pigment to your epoxy is easy. Follow the normal instructions for mixing your epoxy. Once it's mixed, add the pigment and mix it in. That's it. The type of pigment you choose matters a lot, though. There are many different types of pigment, but not all of them are really good for your epoxy.
Water/oil based paints
If you already have some paints lying around, it may be tempting to simply use them to add color to the epoxy. Do not do this. Water or oil based paints will cause problems with the cure and could ruing the epoxy. Remember that your epoxy is based on a precise chemical formula, and adding anything to it could throw off the chemical reaction that makes epoxy.
Important Note: Epoxy and Water/Oil Do NOT Mix! Using water-based or oil-based paints can cause a reaction with the epoxy which could ruin your project, or cause the epoxy to heat up, smoke, crack, etc.
These paints also will not effectively color your epoxy. They are not meant to be diluted, and using them in epoxy would require a lot of dilution, leading to dull colors.
Liquid epoxy pigments
These are probably the most popular choice, because it's easy to mix them in evenly. You can get great results from these and you'll get nice, even coloring. Unfortunately, because they are liquid, even coloring is all you will get. Your epoxy will be one flat color, and will be evenly colored throughout. If that's what you want, then these are perfect. If you want more variation in the coloring, keep reading.
Pigment powders deliver rich, deep colors. They won't mix in as easily or as evenly as liquid pigments, which sounds like a bad thing but it really isn't. It creates slight variations in the coloring that can add a lot of visual interest to the finished product. Instead of a perfect, flat blue, you'll get a blue that varies intensity from one spot to another, fading from bright to dark, royal to light blue, and more.
Mica Pigment Powders
These are usually the best way to color your epoxy. Mica is a naturally occurring mineral that has a metallic sheen to it. These powders are made of ground up mica with pigment added. With these, you get all the advantages of a pigment powder- deep colors and nice variations- along with a great metallic finish that really makes the epoxy shine.
How much pigment to use
Remember that making epoxy requires a chemical reaction, and adding too much of any substance can throw that reaction off and prevent the epoxy from curing properly. That's one of the reasons why pigments are so much better than paints or dyes; they're very concentrated, and you only need a small amount to get the color you want. The general rule is that the amount of pigment should be between 2% and 6% of the weight of the mixture. The best way to measure this is with a digital scale.
Lower than 2% and you may not adequately color the epoxy. Higher than 6% and you are likely to interfere with the reaction that cures the epoxy. Start off closer to 2% and add more if you want more color.
These are very generalized instructions, because each brand of epoxy and of pigment may have slightly different instructions for you. While they are unlikely to vary much from what is listed here, always use the manufacturers recommendations when they differ from ours.