How Long Does Resin Take to Cure? It is difficult to answer this question accurately. Resin can take minutes, hours or even days to cure. Basically, the curing time of resin depends not only on the type of resin you use but also on temperature, humidity as well as resin volume... To better understand the […]
How Long Does Resin Take to Cure? Understanding Resin Curing Time
How Long Does Resin Take to Cure? It is difficult to answer this question accurately. Resin can take minutes, hours or even days to cure. Basically, the curing time of resin depends not only on the type of resin you use but also on temperature, humidity as well as resin volume... To better understand the curing time of epoxy resin, polyester resin, polyurethane resin, UV resin, explore the details below.
Average Curing Times for Different Resins
Below is the curing time of 4 common types of resin on the market and their curing time:
|Resin Type||Curing Time||Temperature|
|Epoxy Resin||48 - 72 hours||75 - 85°F (24 - 30°C)|
|Polyester Resin||24 - 48 hours||75 - 95°F (25 - 35°C)|
|Polyurethane Resin||24 - 72 hours||- 80 - 200°F (-62 - 93°C)|
|UV resin||30 minutes - 2 hours||68 - 77°F (20 - 25°C)|
Resin cure time is the amount of time required for a resin layer or resin mixture to become hard, durable, and achieve optimal mechanical and chemical properties. This process is where the molecules in the resin interact with each other or with the hardener to create a hard and stable network. This is an important stage in the resin usage process, as it determines when the final product can be used or further processed.
Factors Affecting Resin Curing Time
Resin cure time can be affected by many different factors such as resin type, temperature, humidity, etc. Understanding these factors is essential to achieving optimal results in resin-based projects.
There are many types of resin and their variations circulating on the market such as epoxy, polyester and polyurethane... Resins cure through many different mechanisms such as polymerization, cross-linking or chemical reaction with substances. solidify. The curing time of resin varies due to its chemical composition and distinct vulcanization mechanism.
Normally, epoxy resin will have a curing time of about 48 - 72 hours, longer than polyester (24 - 48 hours), polyurethane (24 - 72 hours) or Uv resin (30 minutes - 2 hours). This is because epoxy resin typically undergoes a more complex polymerization process as well as requiring additional stimulation by a catalyst (such as an amine or anhydride) to take place. In addition, epoxy resin is also divided into many different types and each type also has a corresponding curing time.
|Drying time of Epoxy resin|
|Resin type||Table top Epoxy||Deep Pour Epoxy||Marine Epoxy|
|Temperature||75 - 80°F||60 - 85°F||70 - 80°F|
|Flood/Deep coat ( Non-final)||4 - 10 hours||12 - 24 hours||4 - 10 hours|
|Flood/Deep coat ( Final)||Minimum: 72 hours||Minimum: 72 hours||Minimum: 1 - 4 days|
|Seal coat||Wait for hours before applying additional resin coats|
If you want to learn more about the types of resin available on the market, read our article 10+ Different Types of Resin & Their Applications for more useful information.
Each type of resin requires a specific curing agent or catalyst to initiate the curing process. These agents contain active ingredients that initiate chemical reactions within the resin, leading to the formation of cross-links or bonds and converting the resin from a liquid to a solid state. The hardener will determine resins cure time. If the ratio of hardener is greater than that of resin, the curing time will be faster; conversely, if the hardener is less, the resin's curing time will be longer.
However, too little and too much hardener can cause the resin to fail to harden or crack due to over-curing. Therefore, be sure to select the appropriate hardener and the correct mixing ratio to achieve the desired resin cure time and maintain the integrity of the resin.
75 - 85°F (24 - 30°C) is the best temperature to cure resin. However, to adjust the freezing time you can adjust the temperature. The warmer the temperature, the faster the curing speed, specifically, resin cure time is 180 minutes at 60°C, 50 minutes at 70°C and only 20 minutes at 80°C.
On the contrary, when the temperature decreases, the curing process slows down. When the temperature is below 22°C, each degree decrease will cause the resin's hardening process to slow down by 15 - 25%. This affects how long you can work with the resin before it begins to fully cure.
Temperature can also affect the stability of reactants in resin and curing agent mixtures. If the temperature is too high, an unwanted explosion or decomposition reaction may occur. If the temperature is too low, there may not be enough energy to stimulate the curing reaction. This can result in the resin not curing completely or curing imperfectly.
Maintain the optimal temperature range recommended by the resin manufacturer for consistent curing and best results.
Moisture in the air can react with the resin during the curing process, creating small air bubbles. These air bubbles will reduce the hardness and durability of the resin, especially moisture-sensitive plastics such as some polyurethane resin.
Additionally, moisture in the air can slow down the curing process of the resin because water will compete with the resin components to react. The higher the humidity in the air, the greater the influence of humidity on the curing process of the plastic.
Therefore, you need to ensure a dry, cool working environment or use a dehumidifier to help minimize the penetration of moisture into the product, thereby helping to improve the hardness and durability of the product. Humidity below 80% is good for the resin to harden, however 50 - 60% is the perfect humidity for smooth and glossy results. Any humidity greater than 80% will cause the resin to have a sticky feel and waxy texture.
Larger volumes of epoxy resin
Large amounts of resin will reduce the reaction rate between resin components. This is because the components of the resin will have to travel a greater distance to react with each other. If not careful, larger amounts of epoxy resin can also lead to foam formation in the mixture.
Besides, too much epoxy resin can create a larger amount of heat during the curing process. This can affect the uniformity of the surface and easily cause defects.
When working with larger quantities of epoxy resin, technical control and adherence to the manufacturer's specific instructions are important to ensure that the curing process occurs effectively and reliably.
When you pour a layer of resin, curing occurs from the surface exposed to air or the bottom surface of the layer above. Therefore, the thickness of the resin layer will affect the curing speed.
Thicker resin layers will require longer to completely cure than thinner layers. Besides, the thicker the resin layer, the higher the risk of air bubbles, which, in turn, can reduce the hardness and durability of the product. Additionally, a thick layer of resin also creates a higher risk of unwanted shrinkage or crack formation during curing.
To avoid these problems, it is important to carefully pour one thin layer of resin at a time or use a medium heat dryer to promote curing when working with thicker layers.
Each type of resin will have different processing methods and mixing ratios to ensure the best results, for example the mixing ratio of epoxy resin is 1:1. If the mixing ratio is incorrect, it can result in the curing process occurring too quickly or too slowly than desired. If the curing agent ratio is small, the resin will not cure completely, making the product soft and sticky. On the contrary, a high curing agent ratio will cause the resin to cure too quickly, giving you not enough time to work with it. The resin will become brittle and crack easily.
In particular, do not add any other catalysts or solvents to the resin mixture for the purpose of promoting the curing process. Carefully read the resin mixing instructions in the manufacturer's instructions. At the same time, use measuring tools such as measuring cups or scales to ensure accuracy.
The reactants in resin require oxygen to react with each other. Adequate ventilation ensures that the curing process of the compound proceeds faster and promotes successful and high-quality curing results.
At the same time, ventilation will help circulate air and remove moisture in the air, thereby helping the resin cure faster. You can ventilate by opening windows or doors for natural ventilation or using a fan.
On the contrary, in a poorly ventilated environment, the amount of oxygen will be limited, leading to slower resin cure time. Insufficient ventilation can also lead to problems such as a sticky surface or air bubbles trapped in the resin.
Types of hardener
Hardeners are divided into two types: fast hardeners and slow hardeners.
The fast hardener requires 70°F (21℃) which is the perfect heat level to yield the best results, so it is suitable for areas with cool temperatures or places with frequent temperature changes. Although it is a fast hardener, it takes 1 - 4 days to completely harden under ideal temperature conditions.
In contrast, slow hardeners require a higher temperature environment, above 80°F (26.7℃). This type of hardener is suitable for warmer places or people who need a lot of time to work with resin. And its curing time is the same as the quick hardener, from 1 - 4 days. Typically, slow-setting agents create a stronger bond than fast-setting agents, but the difference is not significant.
Types of coatings
Different coatings can affect the rate of resin curing by affecting chemical reactions, heat dissipation, and oxygen exposure. Resin coatings are divided into 3 main types: seal coats, flood coats, deep pouring coats.
Because seal coats are not the final coat, you do not need to wait for them to dry completely. 4 hours is enough time for this coating to cure so you can continue adding layers of resin on top.
If your final flood coats are epoxy resin, the curing time will take a lot longer, usually about 72 hours. If it's not the last layer, just wait 4 - 10 hours for it to partially set and then continue with the rest of your work.
If the deep coat is your final coat, the recommended time to dry completely is 72 hours in temperatures around 60°F - 85°F . At the same time, humidity must also be maintained at 60% or lower during the curing process. On the contrary, if the deep paint layer is not the final paint layer, the curing time is only about 12 to 24 hours. And of course you must ensure the air humidity is always below 60%.
How to Make Resin Cure Faster?
Do you want your results to be completed faster? You can speed up the curing process of resin by applying some simple measures below.
High ambient temperatures can help accelerate the curing process of the resin. The ideal temperature for perfect vulcanization of resin is 75 - 85°F (24 - 30°C). If the temperature increases gradually by 20°F, the curing time will decrease by 20 - 25%. At the same time, an additional temperature increase of 20°F - 30°F will help the curing process 30% faster.
However, make sure to keep the temperature stable during the first 24 hours of curing. Because if the temperature increases or decreases erratically, it will cause dents or roughness to form on the surface.
One of the most effective methods to speed up the curing process of resin is to use a Powerblanket. It can provide temperatures up to 180°F and ensures even heat dispersion to the resin surface. Alternatively, you can use a heater or heat lamp so you can control the temperature during the working and curing process. However, be careful not to use too high a temperature as it can cause color changes. color or properties of resin.
Exposure to ultraviolet (UV) light can be used to stimulate the curing process of some resins. This process is often called UV polymerization or UV curing. This method has short curing time, good control and uniformity of the final product. You just need to place the resin products under UV sources such as sunlight or UV lamps and wait for them to harden. It is essential to ensure that UV light reaches all locations on the resin surface evenly
However, depending on the type of resin, the intensity of UV light and the thickness of the resin layer, the time needed to completely cure will vary. Normally, the resin will harden within a few minutes to a few hours. Read the instructions to make sure you give the resin enough time to cure completely. Above all, it should be noted that using UV light to accelerate the curing process only works on resins specifically designed for UV curing.
Incorporating accelerators or curing additives into the resin mixture is a common way to speed up the curing process and without affecting the properties of the final product. These substances are often called "catalysts" or "hardeners". When adding catalyst to resin, you need to mix thoroughly to ensure that the catalyst is evenly distributed.
For example, using epoxy curing additives provides curing speed and durability properties to epoxy resin mixtures. Catalyst MEKP, a popular additive, is used for polyester resin to achieve fast and efficient curing.
Depending on the type of resin and specific requirements, choosing the right accelerator or curing additive plays an important role to ensure the curing process takes place safely and achieves optimal results. It is important to follow the instructions and recommended dosage to avoid excessive acceleration and ensure safety.
Thin Layer Application
Pouring thin layers of resin is a common technique used to speed up the curing process because thinner layers dissipate heat more effectively. Using a thin layer also minimizes the risk of shrinkage, facilitates better curing and prevents the formation of unwanted air bubbles. The resin should be poured into layers, each layer about 2 - 3mm thick.
To make the resin layers thin and even, you can slowly pour the resin mixture into the center and then the outside. You can also use a roller or brush to smooth and evenly spread the plastic layer. At the same time, make sure the previous layer is completely dry before pouring the next layer to avoid technical problems and increase the stability of the resin.
For smaller projects, carefully use a heat gun or hair dryer to apply controlled heat to the resin. High temperatures will help the chemical reactions between the components of the resin take place faster, leading to the resin hardening faster without affecting the entire work.
However, be careful to use a heat gun or hair dryer at low temperatures to avoid changing the original color or properties of the resin. The ideal temperature to use a heat gun or hair dryer to accelerate the curing of resin is between 40 - 50°C.
At the same time, always keep the gun about 5 - 7cm away from the surface of the resin and only hold the power source. heat in one position for 2 - 3 seconds to effectively transfer heat to the resin without causing overheating or injury. Perform a test on a small sample to ensure that the curing process is safe and effective.
To summarize, resin curing time depends on many factors, including resin type, resin layer thickness, temperature and humidity. To speed up the drying time of resin, you can increase the temperature, reduce the thickness of the resin layer or use additives. It is important to be patient and carefully monitor the curing process until it is completely hard. Hope the information in the article will help you.
How long does resin take to dry?
The drying time for resin can vary depending on the specific type and brand of resin you are using, as well as environmental factors like temperature and humidity. Generally, most resins will reach a tack-free or touch-dry state within 24 to 48 hours. However, full curing or hardening may take anywhere from several hours to several days, and in some cases, even longer.
Can I speed up resin curing?
Of course you can. Some ways you can apply to speed up resin processing include increasing temperature, adding curing agents, using thinner resin layers as well as controlling the humidity of the working environment.
Can I slow down resin curing?
Yes. Reducing the temperature by working in a cool room or using a fan to cool the resin, adding a cure inhibitor or applying a thicker layer of resin will be the most optimal way to reduce the curing rate of the resin while still retaining its original properties.
Why is my resin still tacky after curing?
One of the most common reasons why resin sticks is improper mixing of resin and hardener. In addition, insufficient curing time, high humidity, low temperature and air bubbles are also causes of a sticky feeling on the resin surface.
How do I know when the resin has fully cured?
The easiest way to tell if the resin is dry is to touch it. If it feels hard and dry to the touch, it is frozen. Another way is that you can observe the color of the resin. When completely dry, the resin will turn transparent like crystal. If it is still opaque or has a matte finish, it will take more time to process.
Can I use a hairdryer or heat gun to speed up curing?
Yes. Using a hair dryer or heat gun can be an effective way to speed up the curing process, but it's important not to let the heat get too hot or too close or too long on the resin surface.
Can humidity affect resin curing?
Yes, humidity can significantly affect the curing process of epoxy resin. In high humidity environments, curing will occur more slowly, lengthening the time required for the resin to completely harden. This can also lead to the plastic surface remaining sticky or opaque as well as air bubbles appearing.