What Could You Do if the Resin Does Not Harden?

What Could You Do if the Resin Does Not Harden?

Jan 19, 2024

Resin hardening is a crucial aspect of art projects involving epoxy resin. When resin fails to harden, it can lead to frustration and setbacks for artists. This issue is a common challenge faced by individuals working with resin, and understanding the reasons behind resin not hardening is essential for troubleshooting effectively. If you're eager to enhance your knowledge about resin art and its technicalities, consider joining an online resin art course to gain a comprehensive understanding and experience.

In this blog, we will learn about the issue of resin not hardening, exploring the factors that can lead to unsuccessful curing and providing practical solutions for each issue. Whether you are an experienced artist or a beginner, gaining insight into addressing non-hardening resin can significantly impact the outcome of your resin artwork.

Reasons for Resin Not Hardening

Resin not hardening can be attributed to several factors, each impacting the chemical process differently:

  • Incomplete Chemical Reaction: When resin and hardener are not mixed in the correct proportions, the chemical reaction necessary for curing is hindered. This can lead to a sticky or soft finish.
  • Inaccurate Measuring: Deviating from the prescribed measurements for resin and hardener can disrupt the curing process, resulting in an incomplete hardening of the resin.
  • Under-Mixing: Thorough mixing is crucial for resin hardening. Inadequate mixing can leave pockets of unmixed resin and hardener, leading to areas of softness or stickiness.
  • Cold Temperatures: Lower temperatures slow down the curing process, sometimes preventing resin from hardening altogether. It's essential to work in a warm environment to facilitate proper curing.

Fixing Common Issues with Sticky and Soft Resin

When dealing with sticky or soft resin, it's essential to take prompt action to save your art project and ensure proper hardening. Here are some effective techniques to fix these common issues:

Scraping Off Wet Material and Applying a Fresh Coat

  • Identify the Affected Areas: Carefully examine the resin surface to locate the sticky or soft spots.
  • Scrape off the Wet Material: Use a plastic scraper or putty knife to remove the sticky or soft resin from the surface gently. Be cautious not to damage the underlying layers.
  • Clean the Surface: Wipe the scraped area with a clean cloth dampened with isopropyl alcohol to eliminate any residue.
  • Apply a Fresh Coat of Resin: Prepare a new batch of resin according to the manufacturer's instructions and carefully apply it over the affected areas. Ensure thorough coverage for a seamless finish.

Using Other Methods like Sanding and Wiping

When dealing with sticky or soft resin, there are alternative methods you can try to fix the issue. These techniques can help you achieve a properly hardened surface. Here are a few options:

Sanding Cured Areas

If you have cured areas with soft spots, sanding can be an effective way to address the problem. Start by using fine-grit sandpaper and gently sand the soft spots until they become smooth and level with the rest of the resin surface. Be careful not to over-sand or apply excessive pressure, as this can damage the artwork. Once you have sanded the affected areas, you can proceed to apply a fresh coat of resin for proper hardening.

Wiping off Residue

Sometimes, sticky or soft resin surfaces can be caused by residue left behind during the curing process. In such cases, wiping off the residue before reapplying resin can help achieve a better result. Use a lint-free cloth dampened with isopropyl alcohol to gently wipe the surface and remove any sticky or tacky residue. This will provide a clean base for applying a fresh coat of resin.

Preventive Measures to Ensure Resin Hardens Correctly

When it comes to resin art, preventing resin from not hardening is crucial for the success of your project. Here are some preventive measures to ensure resin hardens correctly:

Measuring and Mixing Tips

  • Accurate Measurement: Always use accurate measuring tools such as graduated cups or digital scales to measure the resin and hardener in the correct ratios. Even a slight variation in the ratio can lead to incomplete curing.
  • Thorough Mixing: Thoroughly mix the resin and hardener for the recommended duration. Incomplete mixing can result in uneven curing or soft spots in the hardened resin.
  • Complete Chemical Reaction: Ensure that the resin and hardener undergo a complete chemical reaction by following the manufacturer's instructions regarding mixing times and techniques. This will help achieve a strong and fully cured final result.

Proper measurement and thorough mixing are essential for resin hardening, and following these guidelines can significantly reduce the risk of encountering curing issues in your resin art projects.

Creating an Optimal Curing Environment

Following proper techniques, such as accurate measurement and thorough mixing, can help avoid issues with resin curing. Another important factor to consider is the curing environment, specifically the temperature control during the hardening process.

The role of temperature control in resin hardening should not be underestimated. Resin is sensitive to temperature fluctuations, and extreme temperatures can significantly affect its curing time and final hardness. To ensure resin hardens correctly, it is essential to create a warm curing environment that promotes optimal curing conditions. Here are some tips for creating an optimal curing environment:

  • Temperature: Maintain a consistent temperature between 70°F and 80°F (21°C - 27°C) in the area where your resin artwork is placed. Avoid exposing the artwork to extreme heat or cold, as it can interfere with the curing process.
  • Warmth: If the surrounding temperature is too low, you can use heat sources like a space heater or heat gun (from a safe distance) to warm up the area around your resin project. Be cautious not to direct heat directly onto the artwork as it may cause uneven curing or other issues.
  • Covering: While the resin cures, cover your artwork with a cardboard box or plastic container to trap heat and create a warm microclimate. This covering will help maintain a stable temperature and prevent dust or debris from contaminating the surface.
  • Curing time: Allow sufficient time for the resin to cure fully based on the manufacturer's instructions. Rushing the process by increasing temperature excessively or reducing curing time may result in improper hardening.

By controlling the temperature and creating an optimal curing environment, you can enhance resin hardening and achieve better results in your art projects. Remember, while these techniques are helpful in most cases, it is essential to follow the instructions provided by the manufacturer of your specific resin product.

Read Also - What Are The First Steps To Making Resin Art?


Dealing with non-hardening resin can be frustrating for artists. However, it is a common challenge in resin art, and there are various techniques available to address the issue. As we have discussed in this blog, the reasons behind resin not hardening can range from incomplete chemical reactions to inaccurate measuring and under-mixing. Additionally, cold temperatures can also impact resin curing.

It is important to experiment with these suggested solutions but also seek professional advice if needed. If you want to get more into the world of resin art and learn more about troubleshooting epoxy resin, Contact Us on Arts Shala today for comprehensive guidance and expert tips.

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