How To Thin Epoxy


A vibrant orange resin tray with thin epoxy next to two bowls of creamy pumpkin soup garnished with pumpkin seeds, evocative of thin epoxy applications in its smooth texture and consistent color.

Hey there makers! Struggling with epoxy thicker than your morning smoothie? Fret not! Thinning epoxy is a critical skill for enthusiasts and professionals alike. This article delves into they why and how of thinning epoxy, providing you with expert tips to ensure your projects success. 

Why Thin Epoxy?


Thinning epoxy can be a great way to enhance its workability. Thinning can improve the epoxy's ability to penetrate and seal porous surfaces or to flow more easily into intricate molds without introducing bubbles. While none of the Promise epoxy products need thinning, it can be necessary depending on the desired results of your project.


Understanding Epoxy


It's essential to understand the two main components of epoxy: the resin and the hardener. When mixed, these components undergo a chemical reaction that transforms them into a hard, durable plastic. Altering the viscosity without affecting its curing properties requires careful a consideration of thinning materials. 


How To Thin Epoxy With Different Materials


The most common method for thinning epoxy is using solvents. But it's like adding hot sauce to your food – a little goes a long way, and too much can affect the cure of your epoxy. For every 5% of thinner, your epoxy might lose up to 35% of its strength. So, choose your solvent carefully!

The Top 2 Solvents for Thinning Epoxy 


  1. Acetone or Paint Thinner: a powerful solvent that can significantly reduce viscosity. It can also weaken the integrity of the cured epoxy if used in excess. Remember to add no more than 10% of this to your epoxy mix, otherwise your epoxy will not cure properly. 

  2. Denatured Alcohol: prefer a softer approach? Denatured alcohol is your go-to. You can add up to 20% without affecting the quality of your epoxy cure, but it's not as effective as acetone. Your epoxy may also take longer to cure.


If you're not a fan of using solvents, applying a little bit of heat is your go-to option. It's our personal favorite and is a great way to prep your Deep Pour Epoxy and Table Top Epoxy for top notch pours. 

    How To Thin Epoxy With Heat 


    Gently heating the surface or the epoxy itself before application makes it as smooth as butter – without compromising its strength. It's like giving your epoxy a warm hug before it does its magic. We especially recommend putting your bottles in a warm water bath before mixing if you are working in a cooler environment below 65 degrees. 

    Resin artist Nita from Nita's Fluid Woodworks actually puts her mixing containers in warm water baths while she mixes to ensure the perfect epoxy pour. 


    Thinning epoxy can enhance its application potential but requires an understanding of the materials and a careful, methodical approach. Whether you're sealing a wooden boat, casting a piece of jewelry, or coating a countertop, the ability to modify the viscosity of your epoxy can be incredibly beneficial. Remember, the key to success lies in patience, precision, and safety. With these tips and techniques, you're well on your way to mastering the art of thinning epoxy. 

    1 comment

    Great guide on thinning epoxy! The advice on mixing ratios was particularly useful.

    Ms. My

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