Epoxy resin is an exceptionally strong material used for several applications, including as adhesives, sealants, paints, lacquers, varnishes, and in a variety of other creative projects.
But unfortunately, because it comes with high viscosity, it can be difficult to work with and apply. Plus, it doesn’t easily move into those corners and hard-to-reach places, which means air pockets may form and make the epoxy resin not cure correctly.
To avoid this problem, one thing you can do is – thin out the resin a bit with solvents like xylene.
I have thinned out the epoxy using Xylene many times, and it worked great for me. For beginners, however, it can be a bit challenging to mix as Xylene doesn’t dissolve too easily with epoxy resin.
Also, its highly flammable properties make it less common among DIYers and woodworkers. So, what are the other alternatives and solutions? Let’s take a look in the next section.
Thinning Epoxy with Denatured Alcohol
To thin epoxy without compromising its strength, you can use denatured alcohol instead of other potentially more harmful solvents. It’s important to note that denatured alcohol is toxic, but it’s generally considered safer.
To achieve the desired consistency, use a mixing ratio of 15 or 20 percent of the volume. For instance, for 30 fluid ounces of resin, you can mix in two fluid ounces of denatured alcohol.
Thinning Epoxy with Lacquer Thinners or Acetone
For a proper mix, use a ratio of 10 parts epoxy to 1 part acetone or lacquer thinner. These solvents are easy and effective for thinning the material. Also, they evaporate quickly and are unlikely to get trapped in the cured resin.
When working with acetone or lacquer thinner solvents, make sure to use them carefully, as they can weaken the resin’s strength or ruin it if mixed improperly. Also, the use of acetone can cause the color of the cured epoxy resin to change.
Using any kind of solvent also comes with fire hazard risks. Therefore, follow all safety protocols while working with any of these solvents.
Heating Epoxy to Thin It is Best – It Doesn’t Weaken the Resin
Heating up epoxy resin is the recommended method for reducing its thickness without weakening its strength.
When you are heating and thinning epoxy, you are essentially lowering its viscosity which will permit the resin to flow easier and allow it to brush onto the surface more easily. This is especially important on porous surfaces like wood.
To help you understand, think about how canned frosting also thickens. When you microwave frosting for a few seconds, it becomes less viscous and can be poured over a cake. This same principle is used to adjust the consistency of epoxy resin.
- Fill a bucket with very hot boiling water (not more than 115° F.
- Place the closed container of epoxy into the bucket and allow it to sit for several minutes.
- The heat of the water combined with the conductivity of the metal container makes the epoxy resin thinner.
The epoxy resin and the bucket both need to be handled safely so that you don’t burn yourself and also do not overheat the resin.
Moreover, you will have to work quickly when applying the resin after it’s heated since the viscosity will return to normal as it cools again.
If you’re working with wood and need to thin the epoxy you can alternatively heat up the wood and let the epoxy resin remain at room temperature. Mix the hardener and the resin and put it on the warm wood.
As soon as it touches the wood, it will start to thin. As the wood starts cooling, the epoxy will be pulled into the wood and will grow thicker.
The Bottom Line
Sometimes, it may be necessary to thin epoxy resin when working with it. Xylene is an option for achieving the desired consistency, but heating the resin is another option that may preserve its properties better.
No matter which method you select, it’s important to assess the materials and project at hand before deciding so that you get the best possible results.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.