Live Zoom Classes are Here!!

Join me for a fun filled evening with fluid art... in the comfort of your own home.

Why Does my Resin Flash Cure When I Put it into a Mold?

This post contains some affiliate links for your convenience. If you purchase by clicking the link, I will earn a small commission at no additional cost to you! This helps maintain our website and allows us to continue to help you learn more about Acrylic Paint Pouring. Click Here to read my full disclosure policy.

Please do not try this at home. Resin flash curing can be toxic and harmful. Always refer to the instructions and safety directions provided by the specific resin you are using.

Join my friend Kim’s Artistic Pursuits Facebook Group!

Why does my resin flash cure when I put it into a mold?

When Epoxy Resin Flash Cures, it means the resin is curing faster than expected. This might seem like a good thing but in most cases with crafters, it is not. The epoxy resin creates a chemical reaction to heat up and cure. When this is accelerated, the resin can become too hot for the mold causing damage, creating excessive toxic fumes, and causing damage to a crafter’s project.

Flash curing can happen for several different reasons. If your resin is flashing curing when you put it into a mold, it could be due to several factors:

  1. Exothermic reaction: Some types of resin, such as certain epoxy resins, generate heat as they undergo the curing process. When you pour the resin into a mold, the confined space can trap the heat generated, causing the resin to cure faster than usual. This rapid curing is known as flash curing.
  2. Catalyst concentration: Resins typically require a catalyst or hardener to initiate the curing process. If the catalyst concentration is higher than recommended or not properly mixed, it can accelerate the curing reaction, leading to flash curing when the resin is placed in a mold. Always refer to the mixing instructions provided on the bottles for the specific resin you are using!
  3. Mold temperature: The temperature of the mold can affect the curing process. If the mold is warm or heated, it can accelerate the resin’s curing reaction and cause flash curing.
  4. Thin mold walls: If your mold has thin walls or is made of materials that conduct heat well, it can lead to faster heat transfer from the resin to the mold. This increased heat transfer can expedite the curing process and result in flash curing.
  5. Excessive heat or light exposure: If the resin is exposed to excessive heat or intense light during or immediately after pouring it into the mold, it can trigger a rapid curing reaction, leading to flash curing.
  6. Pouring too deep: Always check with the specific brand of resin you are using to see their recommendations. In general, the resin can be safely poured about 1/8″-1/4″ thick, while Deep Pour Resins can be poured about 1-1/2″-4″ thick.

It’s important to note that flash curing may also lead to potential issues like an increased exothermic reaction, reduced working time, or compromised resin properties. It’s recommended to follow the manufacturer’s guidelines to achieve the desired results with your resin casting process.

Resin Flash Cure Fluid Art with Erika

Resin Flash Cure Example

What are the Dangers of Curing Epoxy Resin?

Curing epoxy resin involves a chemical reaction between the epoxy resin and a curing agent, leading to the hardening or solidification of the material. While epoxy resin is widely used and generally safe when handled properly, there are potential dangers associated with the curing process. Here are some considerations:

  1. Skin and Eye Irritation:
    • Epoxy resins and their curing agents can cause skin irritation and allergic reactions. Direct skin contact should be minimized, and protective equipment such as gloves and long sleeves should be worn. In case of contact, affected areas should be washed thoroughly with soap and water.
  2. Respiratory Hazards:
    • Inhalation of vapors emitted during the curing process can cause respiratory irritation. Adequate ventilation is crucial in the workspace to prevent the buildup of fumes. In some cases, respiratory protection may be necessary, especially when working in confined spaces or with large quantities of epoxy resin.
  3. Sensitization:
    • Prolonged or repeated exposure to epoxy resin components may lead to sensitization, causing allergic reactions in some individuals. It’s important to be aware of personal susceptibility and take necessary precautions, including the use of protective clothing and proper hygiene practices.
  4. Toxicity of Components:
    • Some epoxy resin formulations may contain toxic components. Users should carefully read and follow the safety data sheet (SDS) provided by the manufacturer to understand the specific hazards associated with the epoxy resin and its curing agents.
  5. Heat Generation:
    • The curing process of epoxy resin is exothermic, meaning it generates heat. Large quantities of resin curing in an enclosed space without proper ventilation can result in an increase in temperature. This can pose a fire hazard, and adequate precautions should be taken.
  6. Exothermic Reactions:
    • In some cases, particularly with large or thick epoxy applications, the curing process can generate significant heat. This can lead to exothermic reactions that may cause the epoxy to crack or distort if not properly managed.
  7. Equipment and Mixing Risks:
    • Improper mixing ratios or inadequate mixing of epoxy resin and curing agents can result in incomplete curing, reducing the material’s strength and integrity. Additionally, using inappropriate equipment or containers can affect the curing process and lead to safety issues.
  8. Environmental Considerations:
    • Some epoxy formulations may contain substances harmful to the environment. It’s important to follow proper disposal procedures and comply with environmental regulations.

To mitigate these dangers, it is crucial to follow safety guidelines provided by the manufacturer, use appropriate personal protective equipment, work in a well-ventilated area, and be aware of the specific hazards associated with the particular epoxy resin formulation being used. Additionally, proper training and adherence to safety protocols are essential to minimize risks during the epoxy resin curing process.

Is Epoxy Resin Safe to Use?

Epoxy resin is generally safe to use when proper precautions are taken and safety guidelines are followed. However, like many chemical substances, epoxy resin and its associated curing agents can pose risks if not handled correctly. Here are some key considerations for the safe use of epoxy resin:

  1. Personal Protective Equipment (PPE):
    • Wear appropriate PPE, including gloves, long sleeves, safety glasses, and, if necessary, respiratory protection. The specific PPE required may vary based on the type of epoxy resin and curing agent being used.
  2. Ventilation:
    • Work in a well-ventilated area to minimize the inhalation of vapors. Use local exhaust ventilation or wear a respirator if working in an enclosed space or with large quantities of epoxy.
  3. Skin Protection:
    • Avoid direct skin contact with epoxy resin and curing agents. In case of skin contact, wash the affected area thoroughly with soap and water.
  4. Eye Protection:
    • Wear safety glasses or goggles to protect against accidental splashes to the eyes.
  5. Read Safety Data Sheets (SDS):
    • Familiarize yourself with the safety data sheet provided by the manufacturer. It contains important information about the composition of the epoxy resin, potential hazards, and recommended safety precautions.
  6. Mixing Ratios:
    • Follow the manufacturer’s instructions regarding the correct mixing ratios of epoxy resin and curing agent. Incorrect ratios can lead to incomplete curing and compromised material properties.
  7. Proper Mixing:
    • Mix the epoxy resin and curing agent thoroughly and according to the manufacturer’s recommendations. Inadequate mixing can result in uneven curing and affect the material’s performance.
  8. Temperature Considerations:
    • Be aware of the curing temperature requirements. Some epoxy formulations may have specific temperature ranges for optimal curing. Avoid exposure to extreme temperatures during the curing process.
  9. Exposure Limits:
    • Be aware of occupational exposure limits for epoxy resin components. Take measures to minimize exposure to fumes and vapors, especially in confined spaces.
  10. Emergency Preparedness:
    • Have emergency equipment on hand, such as eye wash stations and a first aid kit. Know the proper procedures for handling spills or accidents.
  11. Environmental Considerations:
    • Dispose of waste materials properly and in accordance with local regulations. Some epoxy formulations may contain substances harmful to the environment.

It’s important to note that there are different types of epoxy resins with varying formulations, and the specific safety considerations may differ among products. Always follow the guidelines provided by the manufacturer of the epoxy resin and associated materials. If you have specific questions or concerns, consult with the manufacturer or a qualified safety professional. Overall, when used with care and in accordance with safety recommendations, epoxy resin is a valuable and versatile material for various applications.

Learn Resin Art with Erika!

Paint Pour Academy was created to help streamline the learning process and teach you the basics of Acrylic Paint Pouring and Resin Art while having some fun along the way.

resin art

Save hours of struggle and costly disappointments.
Learn fluid art with a seasoned pro at your side!

Fluid art is so much fun to create, but it can be hard to get the results we want. Start enjoying the art you create with Erika’s curated classes including access to her ebooks, videos, members-only tips and tricks, and so much more!

Leave a Comment

Your email address will not be published. Required fields are marked *

Up your game and learn more with the pros.

View all of Erika's Acrylic Paint and Resin Courses

Shopping Cart