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Differences Between Deep Pour Epoxy Resin and Tabletop Epoxy Resin

February 3, 2026

by jinhua-admin with No Comment Uncategorized

Deep pour epoxy resin (also known as casting epoxy resin) and tabletop epoxy resin (also known as coating epoxy resin) both fall under the two-component epoxy resin system, yet they exhibit significant differences in physical properties, construction requirements, performance characteristics and application scenarios due to distinct core formulation designs and functional orientations. The most crucial difference lies in their working thickness, which in turn leads to a series of consequent differences.

1、Physical Characteristics: Variances in Viscosity and Flowability

Viscosity is the most intuitive difference between the two, directly determining their flow capacity and filling performance.

Tabletop epoxy resin: It has a relatively high viscosity after mixing, with a honey-like consistency and low fluidity. This property allows it to spread slowly and self-level on flat surfaces, ultimately forming a uniform coating of approximately 3 mm in thickness naturally. It can cover surface gaps without additional troweling, making it ideal for creating smooth surface finishes. Some low-quality tabletop epoxy resins only have a self-leveling thickness of about 1.5 mm and require multiple coats to achieve a durable thickness.

Deep pour epoxy resin: It features an extremely low viscosity, almost water-like, with exceptional fluidity. It can easily penetrate wood gaps and mold corners, while facilitating the natural floating and release of air bubbles to avoid bubble residue during thick-layer casting. Its low-viscosity property is the foundation for achieving thick-layer casting, enabling the formation of a relatively thick molded layer in a single application.

2、Construction Parameters: Pouring Thickness, Working Time and Curing Cycle

Tabletop Epoxy Resin: The recommended single pouring thickness is 5–10 mm. If the thickness exceeds this range, the heat generated during curing cannot dissipate in time, which will trigger thermal runaway, leading to surface yellowing, cracking, and shrinkage deformation.It has a relatively short working time, with an operational window of only tens of minutes to 1 hour after mixing. The curing speed is fast: it can achieve initial curing at room temperature in 12–24 hours and complete curing in 24–72 hours. It also supports repainting within a short time (3–6 hours).The mixing ratio is mostly 1:1 by volume, and it has a low operation threshold.

Deep Pour Epoxy Resin: Specifically designed for thick-layer pouring, it can achieve a single pouring thickness of 12–50 mm. To control heat release, its formula adopts a slow-curing system, resulting in an extremely long working time of 3–10 hours or more. For some large-volume pouring products, the working time can be as long as 10 hours, which is sufficient to complete complex mold filling and bubble treatment.Its curing cycle is relatively long: initial curing takes 24–36 hours at room temperature, and complete curing may take several days. It is not suitable for thin pouring; otherwise, it will cause incomplete curing, sticky surfaces, or insufficient hardness.The mixing ratio is mostly 2:1 or 3:1 by volume, with a high requirement for mixing ratio accuracy.

3.Performance Characteristics: Hardness, Heat Resistance, and Stability

Tabletop epoxy resin focuses on surface protection, while deep pour epoxy resin emphasizes molding strength.

Tabletop Epoxy Resin: After curing, it exhibits high hardness, with a Shore D hardness ranging from 70 to 85. It boasts excellent scratch and wear resistance, coupled with superior water and heat resistance, effectively resisting bumps, water stains, and high-temperature contact during daily use. Most products are formulated with UV-protective additives, which reduce yellowing and discoloration caused by sunlight exposure, making them ideal for surfaces exposed to indoor environments for long periods. However, it has poor flexibility and relatively high brittleness, which may lead to cracking under severe impact.

Deep Pour Epoxy Resin: Its hardness after curing is lower than that of tabletop epoxy resin—a deliberate design choice. The deep pour formulation requires a slower reaction rate to enhance toughness and reduce internal stress, resulting in a slightly “softer” yet more flexible material compared to tabletop epoxy resin. It typically has a Shore D hardness of 60 to 75. Its key advantages include low curing shrinkage, excellent dimensional stability after thick-layer molding, and resistance to deformation. Due to its slow curing process, the internal stress is evenly distributed, ensuring overall toughness that surpasses that of tabletop epoxy resin. It also offers good yellowing resistance, but its UV protection capability is generally weaker than that of tabletop epoxy resin, so it may still discolor when exposed to prolonged sunlight.

4、Applicable Scenarios: Functionality Determines Application Scope

The applicable scenarios of the two are strictly aligned with their performance characteristics and cannot be arbitrarily substituted, otherwise it will lead to project failure.

Tabletop Epoxy Resin: Its core application is surface coating protection, suitable for creating flat, high-gloss, and durable surface layers. Typical applications include sealing the surfaces of dining tables, bar counters, countertops, and solid wood furniture, as well as curing the surface layers of coasters, decorative panels, and mixed-media artworks. It can be mixed with pigments such as mica powder and alcohol ink to create colorful decorative surfaces, while also sealing wood and preventing deformation caused by moisture absorption. Note that if it is used outdoors, additional UV protection additives must be added or UV-protective tabletop epoxy resin should be purchased.

Deep Pour Epoxy Resin: Its core application is three-dimensional molding and thick-layer filling, suitable for the production of molded parts that require a certain thickness. Typical applications include river tables (filling wood gaps), resin castings, silicone mold molding (jewelry, pen holders, ornaments), large-scale artworks encapsulation, and building gap filling. Objects such as metal, wood, and flowers can be embedded and encapsulated within it to create a transparent and three-dimensional effect. Due to its insufficient hardness, large molded parts (such as river table tops) usually require an additional layer of tabletop epoxy resin to be applied on the surface, balancing thickness and surface durability.

5.Summary and Selection Principles

Essentially, tabletop epoxy resin is a “coating resin” focused on thin-layer protection and high-gloss decoration; deep pour epoxy resin is a “molding resin” designed for thick-layer filling and three-dimensional molding. The selection of the two must follow the “thickness matching” principle:

For thin-layer (1–3 mm) surface protection and high-gloss decoration, with a focus on fast curing and high hardness, choose tabletop epoxy resin.

For thick-layer (≥3 mm) molding, gap filling, and object encapsulation, requiring bubble and shrinkage control, choose deep pour epoxy resin.

For complex projects (e.g., river tables), a combination can be used: deep pour epoxy resin fills gaps to achieve the required thickness, while tabletop epoxy resin is applied to the surface to enhance hardness and wear resistance.

Methods and Techniques for Color Matching of Deep Pour Epoxy Resin

January 27, 2026

by jinhua-admin with No Comment Uncategorized

Color mixing is an extremely crucial process when using deep pour epoxy resin for creating large artworks, river tables and other pieces. It requires a balanced consideration of color uniformity, curing stability and visual effects. Due to the fluidity, bubble release characteristics of deep-pour epoxy resin, as well as the amplifying effect of its thickness on color presentation, the color mixing process differs significantly from that for surface coating. Below are some of Jinhua’s experiences in color mixing for deep-pour epoxy resin, provided for your reference.

1.Pigment Selection and Compatibility Testing

The chemical properties of deep-pour epoxy resin are sensitive, making pigment selection a critical step that directly impacts the curing performance. It is therefore essential to avoid non-specialized pigments in the first place and select the suitable pigment type according to specific requirements.

（1） Recommended Pigment Types and Their Applicable Scenarios

Specialized liquid resin dyes: Best suited for deep pouring, with excellent solubility that enables complete fusion with resin, delivering a uniformly transparent or translucent hue without any graininess. Ideal for creating gradient and transparent effects (e.g., simulating water bodies or amber textures). A single drop can color 20–100g of resin (standards vary by product; refer to the product instructions), offering easy dosage control and minimal impact on curing.

Mica powder pigments: Powder-form with natural mineral ingredients, they create pearlescent, metallic luster or a delicate frosted texture, ideal for crafting deep-pour artworks in retro and gorgeous styles (e.g., resin river tables, decorative ornaments). Note to disperse in advance to prevent clumping.

Specialized epoxy resin pastes/color gels: High in concentration and hiding power, they are suitable for projects requiring solid, opaque effects, such as custom color blocks and embedment encapsulation. Strictly control the dosage to avoid compromising the resin’s fluidity.

Alcohol inks: Ideal for creating artistic textures like marble and cell patterns, with vivid colors and excellent spreadability. For accent use only; excessive amounts will damage the resin curing system, leading to a tacky surface or cracking.

（2）Prohibited Pigments

Non-specialized colorants such as food colorings, regular nail polishes and low-cost craft pigments can easily cause incomplete curing of the resin (resulting in a tacky or soft finish), color bleeding or excessive bubbling, which completely ruins the effect of deep pouring. In addition, any colorants containing water or oil must be avoided entirely to prevent curing failures.

（3）Compatibility Testing

Regardless of the pigment used, a small-batch test must be conducted before official color mixing: Take 50–100g of resin (before mixing components A and B in the specified ratio), add the planned dosage of pigment, stir thoroughly and pour into a small mold. Observe the curing condition for 24–48 hours. Proceed with mass mixing only after confirming no abnormalities and that the color meets expectations. This step is mandatory especially when using a new brand of pigment or resin for the first time.

2、Standard Color Mixing Operation Procedure

Color mixing for deep-pour epoxy resin shall follow the principles of “Disperse First, Mix Later, Control Dosage, Prevent Bubbles”, with the procedures as follows:

（1） Preparations

Set up a clean, well-ventilated and constant-temperature workbench (20–25℃) to prevent dust contamination. Prepare dry mixing containers, stirring rods (silicone rods are recommended for easy cleaning and reduced bubble formation), measuring cups, pigment tools and test molds. Bring the deep-pour epoxy resin to room temperature in advance to ensure stable fluidity.

（2）Pigment Pre-dispersion (Critical Step)

For powder pigments (e.g., mica powder), first mix a small amount of Resin Part A (without hardener) with the pigment and stir into a uniform, particle-free slurry, then pour the slurry into the remaining Part A and stir thoroughly. This step prevents pigment clumping and avoids defects such as color spots and streaks after deep pouring. Liquid pigments can be directly added to Part A in small, separate portions without pre-dispersion, but the addition must be done dropwise and slowly.

（3）Resin Mixing & Color Tuning

Accurately weigh Resin Parts A and B in accordance with the ratio specified in the resin manual (usually 2:1 or 1:1 by volume). First, stir Part A with the pre-dispersed pigment thoroughly to ensure uniform color throughout (stir slowly in a circular motion along the container wall to minimize bubble generation).

Add Part B and continue stirring for 3–5 minutes until the mixture becomes completely transparent and free of floccules. Scrape the bottom and side walls of the container repeatedly during stirring to avoid residual unmixed resin, which may cause local color unevenness or poor curing.

Color fine-tuning: Follow the principle of “small amounts, multiple additions”. Stir for 30 seconds after each pigment addition before checking the color. Since deep pouring amplifies color concentration (the color of a thick layer is 30%–50% darker than a thin layer), leave room for lighter color during fine-tuning to prevent the final color from being overly dark.

（4） Bubble Treatment & Settling

After color mixing, let the mixing container stand for 2–5 minutes to allow bubbles generated by stirring to float up naturally. Then, quickly sweep the surface with a heat gun (low temperature setting, 15–20cm away) or a butane torch to eliminate residual bubbles. Deep-pour epoxy resin has high inherent fluidity, so minor bubbles can float up on their own—avoid overheating to prevent interference with the resin’s curing reaction.

3、Key Techniques and Dosage Control

（1） Golden Rule for Dosage

The total dosage of pigments must be strictly controlled at 1%–5% of the total weight of the mixed resin (Parts A + B), with a maximum limit of 10%. Excessive pigments will disrupt the chemical balance of the resin, leading to slow curing, a tacky surface, insufficient hardness, and even shrinkage and cracking. A small amount of pigment is sufficient to achieve deep coloring—especially for liquid dyes, just 1–2 drops can create a pale color effect.

（2） Tips for Optimizing Color Effects

Transparent effect: Select liquid dyes and control the dosage at 1%–2%. Combined with transparent deep-pour epoxy resin, it can create a glass or gem-like texture, ideal for embedding specimens and metal parts.Pearlescent/metallic effect: Control the dosage of mica powder at 2%–3%, add it after pre-dispersion, and lightly sweep the surface with a heat gun after pouring to enhance the layered sense of luster.Artistic textures: When adding accents with alcohol inks, first pour a solid-color resin base. After the surface slightly gels, drop a small amount of ink, gently guide the texture with a toothpick, and then use a heat gun to assist in diffusion to prevent excessive ink penetration.Color calibration: The cured resin color may differ from its liquid state (usually slightly darker). Record the color comparison between liquid and cured states during the testing phase for precise control in bulk color mixing.

（3） Troubleshooting Common Issues

Color unevenness/streaks: Mostly caused by inadequate pigment dispersion or incomplete stirring. The solution is to enhance the pre-dispersion step, extend stirring time during mixing and scrape the dead corners of the container to avoid local pigment accumulation.Residual bubbles: In addition to static settling and heat defoaming, a small amount of specialized defoamer (dosage ≤ 0.5%) can be added during color mixing. However, the compatibility between the defoamer and pigments must be tested first to avoid color distortion.Color fading after curing: Choose UV-resistant pigments and avoid ordinary red and purple pigments that are prone to oxidation. If the finished product needs long-term exposure to sunlight, a UV protective coating can be applied.

4.Safety and Post-Procedure Notes

Wear gloves and a mask during color mixing and pouring to avoid direct skin contact with pigments. Meanwhile, keep the area well-ventilated to reduce inhalation of volatile fumes from resin and pigments. Pour the remaining colored resin within the working time (usually 30–40 minutes, subject to the resin instructions) to prevent operational failure due to resin thickening.

Maintain a clean and constant-temperature environment during the curing stage, and avoid vibration and extreme temperature differences. Deep-pour epoxy resin typically requires 24–72 hours for full curing. Do not touch or move the resin before complete curing to ensure stable color and a smooth surface.

How to properly use deep pour epoxy resin?

January 14, 2026

by gdjh--admin with No Comment Uncategorized

Deep pour epoxy resin is a two-component (resin + hardener) epoxy resin system. Its core characteristic is the ability to achieve relatively thick layers in a single casting (general casting thickness ranges from 1 inch to 8 inches, with some industrial-grade products reaching 12 inches). Simultaneously, by controlling the formulation, it achieves a long gel time and low exothermic temperature rise, avoiding cracking and shrinkage problems caused by heat accumulation during curing.

Its core advantages stem from precise formulation design: on the one hand, its low viscosity gives it excellent self-leveling and air release capabilities, resulting in a bubble-free, crystal-clear molding effect. Some products also contain UV inhibitors to improve resistance to yellowing. On the other hand, its 100% solids content and low VOC (volatile organic compound) properties enhance safety in use. After curing, it possesses high hardness, wear resistance, chemical corrosion resistance, and waterproof and moisture-proof properties, and is not prone to deformation or aging over long-term use.

The key difference between deep-cast epoxy and ordinary epoxy resin lies in the upper limit of casting thickness and curing characteristics: the single casting thickness of ordinary epoxy is usually 2-5mm (a single casting thickness exceeding 5mm will cause violent exothermic curing leading to runaway, central scorching, surface cracking, and performance degradation, which is why “deep-cast epoxy” and “ordinary epoxy” must be strictly distinguished), requiring multiple layers, while deep-cast epoxy can significantly reduce the number of construction layers; the surface drying time is also longer (usually 6-14 hours), which can meet the needs of complex shape design or object embedding, and the curing cycle is relatively long (complete curing requires 7-14 days), but the structural stability after molding is stronger.

With a wide range of applications, covering both artistic creation and industrial fields, it can be used to create river tables, resin jewelry, encapsulated ornaments, large decorative sculptures, etc. Specific specifications must be followed during use. Typically, it needs to be precisely mixed at a volume ratio of 2:1 (resin:hardener, some products can reach 3:1). After thorough mixing, it should be poured. An ambient temperature of 18-27℃ and humidity below 70% are more conducive to molding. Hot air can be used to help remove air bubbles generated during mixing.

The core of correctly using deep-cast epoxy resin is to control four key aspects: environmental control, precise mixing ratio, standardized operation, and proper curing. Combined with its characteristics of “long working time, low heat release, and thick-layer casting,” following the standardized operation of the entire process—”preparation—mixing—casting—air bubble removal—curing”—can effectively avoid problems such as air bubbles, cracking, shrinkage, and yellowing, ensuring the molding effect. The following are detailed steps and precautions:

1、Preliminary preparations: Dual control of environment and materials

（1）Environmental condition control (core critical factor)

Temperature control: Temperature control is a crucial aspect of deep-cast epoxy resin processes. The ambient temperature needs to be stable between 18-27℃, with the optimal temperature being 22-25℃. Too low a temperature will lead to increased resin viscosity, mixing difficulties, slow curing, or even incomplete curing; too high a temperature will shorten the working time, exacerbate the exothermic reaction, and increase the risk of cracking. Avoid operation in direct sunlight, excessively ventilated environments, or environments with large temperature differences. In winter, avoid using “frozen materials” directly; allow them to stand indoors for 24 hours before use.

Humidity Control: Humidity control is even more important than temperature control. The optimal ambient humidity range is 40%-60% RH, with a maximum limit of 70% RH. High humidity can cause the resin surface to turn cloudy, remain tacky after curing, and even compromise adhesive strength. Dehumidifiers should be used to regulate humidity during rainy seasons or plum rain periods.

Ventilation requirements: Choose a well-ventilated space. Although the VOC content of deep-cast epoxy resin is low, a slight odor may still be generated during mixing. Ventilation can prevent odor accumulation and reduce dust falling into the uncured resin.

（2）Material and tool preparation

Core Materials: Confirm the type and shelf life of the deep-cast epoxy resin (resin + hardener), prioritizing products suitable for the current application scenario (e.g., choose a high-transparency, anti-yellowing version for artistic creations, and a high-strength, corrosion-resistant version for industrial applications). Check for sedimentation or clumping. If slight sedimentation occurs, slowly stir the resin 30 minutes before mixing (to avoid air bubbles).

Tool Preparation: ① Mixing Container: Use a clean, dry, and oil-free plastic or glass container. The container capacity should be 1.5-2 times the estimated casting volume (allowing for mixing space to prevent overflow), and the inner wall should be smooth (for even mixing); ② Stirring Tool: Use a wooden, plastic, or silicone stirring rod. Avoid using metal rods (which may introduce impurities or affect curing); ③ Auxiliary Tools: Measuring cup (with graduations for precise proportioning), heat gun/butane torch (for removing air bubbles), gloves (corrosion resistant), goggles, mask (for protection), and release agent (if demolding is required, such as for making a river table, apply to the inner wall of the mold beforehand).

Substrate preparation: If pouring onto a substrate such as wood or concrete, ensure the substrate is dry (moisture content below 10%), clean, free of oil and dust. Wood needs to be sanded smooth beforehand, and concrete needs to have loose particles removed and be dry. If necessary, apply a layer of epoxy resin primer to enhance adhesion and prevent air or moisture from the substrate from seeping into the resin and causing bubbles.

2、Core operations: precise mixing and standardized pouring

（1）Precise Mixing Ratio (Critical Step, No Deviation Allowed)

For deep-cast epoxy resin, a volume ratio of “resin:hardener = 2:1” is typically used (refer to the product instructions for specific details; some products may use a 3:1 ratio). Precise measurement using a graduated measuring cup is essential; estimation based on feel is strictly prohibited.

Measurement Points: Pour in the resin first, then the hardener, avoiding reversing the order. The measuring cup should be placed horizontally, with your line of sight aligned with the graduations to minimize errors.

Impact of Deviation: Inaccurate mixing ratios will directly lead to incomplete resin curing, resulting in problems such as a sticky, soft surface and insufficient hardness. Even adding more material later cannot salvage the situation.

（2）Mix thoroughly (to avoid air bubbles and uneven curing).

Stirring Method: Slowly stir along the inner wall of the container with a stirring rod in the same direction (clockwise or counterclockwise) at a moderate speed to avoid introducing a large amount of air during rapid stirring. Ensure the bottom and corners of the container are completely covered during stirring. Mix for 3-5 minutes until the resin and hardener are fully combined, and the solution is transparent, uniform, and free of streaks, particles, and turbidity.

Secondary Stirring (You can choose to stir only once, but secondary stirring is recommended for better air bubble release): Pour the mixed resin solution into another clean container and stir a second time (1-2 minutes). This further ensures uniform mixing and helps release some of the tiny air bubbles generated during stirring.

（3）Standardized pouring (controlling flow rate and thickness)

Pouring Timing: After mixing, let stand for 1-2 minutes (allowing tiny air bubbles to rise naturally) before pouring. Avoid prolonged standing time, which can increase resin viscosity and affect flow and spread.

Pouring Method: Slowly pour the resin along the edge of the mold or substrate, allowing it to self-level naturally. Do not pour directly into the center (to avoid impact and air bubbles). For larger areas or complex molds, pour slowly in sections to ensure even coverage without any gaps.

Thickness Control: Strictly adhere to the maximum single-pour thickness specified in the product (typically 1-8 inches). Excessive thickness will prevent heat dissipation during curing, leading to resin cracking and shrinkage. For thicker finished products, pour in batches, waiting for each layer to fully gel (usually 6-14 hours) before pouring the next layer. The total thickness of adjacent layers must still meet product requirements.

3、Bubble removal and surface finishing

（1）bubble removal

Preliminary Defoaming: After pouring, let stand for 3-5 minutes to allow air bubbles generated during mixing and pouring to rise naturally to the surface.

Secondary Defoaming: Use a hot air gun or butane torch (set to low flame) to evenly move along the resin surface (10-15 cm away from the surface to avoid localized high temperatures that could burn the resin). Use heat to break up the air bubbles. For areas difficult to reach with hot air, such as mold edges and corners, gently tap the outer wall of the mold to help the bubbles rise. During operation, be careful not to leave the hot air gun/torch in the same position for too long to prevent localized overheating, discoloration, or premature curing of the resin.

Special Cases: If there are many air bubbles in the resin, vacuum defoaming of the mixture can be performed before pouring (requires specialized vacuum equipment). Defoaming time is 1-2 minutes, until the bubbles completely disappear.

（2）Surface finishing

Besides air bubbles, surface smoothness and detail processing directly affect the final product’s quality. Surface preparation must be completed before resin gelling. The specific steps are as follows: After air bubble removal, check the resin surface for smoothness. If there are drips or bumps, gently guide the resin to self-level. If decorative elements (such as wood, stone, or dried flowers) need to be embedded, gently place them in before resin gelling (during the working time), adjusting them to the appropriate position, avoiding forceful pressing to prevent air bubbles. If new air bubbles form after placement, de-bubbling treatment must be performed again.

4、Post-Curing Maintenance and Treatment

（1）Curing Stage Protection

Gel stage (6-14 hours): During this stage, the resin gradually loses its fluidity. Do not touch or move the mold or finished product to avoid scratches or dents on the surface. Keep the environment clean to prevent dust and debris from falling into the uncured resin.

Initial curing (24-48 hours): The resin surface hardens and can be lightly touched, but it is not yet fully cured. Do not bear weight, sand, or demold (specific times are subject to the product instructions). If the ambient temperature is low, the initial curing time needs to be extended.

Complete curing (7-14 days): The resin is completely cured internally, possessing final hardness, strength, and corrosion resistance. Demolding, sanding, polishing, and other subsequent processing can be performed at this time. Before complete curing, maintain a stable environment and avoid drastic temperature changes and vibrations.

（2）Subsequent processing

After complete curing, if there are minor imperfections on the surface of the finished product (such as small bubbles or rough edges), sandpaper can be used to smooth it out, and then polishing can be performed to restore the high transparency and gloss of the surface. If used in industrial settings, no further processing is required, and it can be put into use directly.

5、Safety and Common Problem Avoidance

（1） Safety Precautions

Personal Protective Equipment: Wear gloves, goggles, and a mask throughout the operation to avoid direct contact of the resin with skin and eyes. If the resin comes into contact with skin, wash immediately with soap and water. If it splashes into eyes, rinse thoroughly with plenty of water and seek medical attention immediately.

Contraindications: Smoking and open flames are strictly prohibited near the resin (some resin components are flammable). Keep out of reach of children and pets. Do not pour uncured resin down the drain; seal it and dispose of it as hazardous waste.

（2）Common problems and avoidance methods

Surface stickiness and incomplete curing: This is mostly caused by mixing ratio deviations or excessively low ambient temperature. The solution is precise mixing ratios and controlling the ambient temperature between 18-27℃. If problems have already occurred, slight stickiness can be removed by sanding after complete curing; severe stickiness requires removal and re-pouring.

Cracking and shrinkage of finished products are mostly caused by excessive thickness of a single pour, heat accumulation, or large temperature differences in the environment. The way to avoid this is to strictly control the thickness of a single pour and keep the curing environment temperature stable.

White haze on the surface: This is mostly caused by excessive ambient humidity or excessively high moisture content in the substrate. The solution is to control the ambient humidity below 70%, pre-dry the substrate, and apply a sealing primer if necessary.

how long does deep pour epoxy take to cure?

January 8, 2026

by gdjh--admin with No Comment Uncategorized

The curing time of deep-poured epoxy resin is not entirely consistent. It mainly depends on three key factors: product formulation, pouring thickness and environmental conditions. The entire curing process can be divided into three stages: gelation/surface drying, initial curing and full curing, with significant differences in the time range of each stage.

The following are reference standards based on general industry norms and Jinhua Resin products (for reference only):

1、Core solidification stage and reference time

The curing of deep-poured epoxy resin is a chemical reaction process between epoxy resin and curing agent, which involves an irreversible transformation from a liquid state to a transparent solid state.

The time reference for each stage is as follows:

（1）Gelation/Surface Drying Stage (touchable without stickiness)

During this stage, the epoxy resin gradually thickens from a liquid state, loses its fluidity, and becomes dry and non-sticky to the touch (i.e., the “tacky cure” state). This typically occurs around 24 hours after mixing, but may extend to 48 hours for some slow-drying products; if the ambient temperature is high (e.g., close to 75°F/24°C), it can be shortened to 18-24 hours. The key function of this stage is to provide an operational window for subsequent multi-layer casting. If multiple coatings are required, it is recommended to complete them at this stage (to avoid the need for additional sanding to increase adhesion after complete curing).

（2）Initial Curing Stage (transportable/for simple processing)

At this point, the epoxy resin has fully hardened and can be handled, sanded, and trimmed, but it has not yet reached its maximum strength. The initial curing time for most mainstream deep-cast epoxy resins is 24-72 hours: fast-curing products reach this state in 24-36 hours (under a standard environment of 70°F/21°C), while conventional products require 48-72 hours. For products used in river tables or large-scale craft casting, it is generally recommended to perform subsequent processing after initial curing to avoid deformation caused by stress before hardening.

（3）Full curing stage

Once epoxy resin has fully cured, it will form a hard, glassy texture, possessing all the properties of water resistance, abrasion resistance, and impact resistance. Only then is it suitable for formal use. This stage takes a relatively long time, typically 5-7 days. For some high-quality products or thick-layer casting scenarios (such as single casting thickness exceeding 1 inch), complete curing may take 1-2 weeks until peak strength is reached.

2、Key factors affecting curing time

深The curing time of epoxy resin is affected by a variety of factors. In actual operation, the following points should be paid special attention to avoid incomplete curing (stickiness, softening) or performance degradation due to unsuitable conditions:

（1）Pouring thickness (the most critical influencing factor)

“Deep casting” of epoxy resin is defined as a single pour thickness ≥ 0.5 inches (1.27 cm). The greater the thickness, the longer the curing time:

• Single pour thickness 0.5-1 inch: Initial curing 24-48 hours, complete curing 5-7 days;

• Single pour thickness exceeding 1 inch: Requires multiple pours (each layer spaced 24-48 hours apart), extending the overall complete curing time to 7-14 days; If a single, thick pour (e.g., exceeding 2 inches) is attempted, it may cause yellowing, cracking, or even failure to cure due to the inability to dissipate internal heat.

（2）Ambient Temperature and Humidity

Epoxy resin curing relies on a chemical reaction, and temperature directly affects the reaction rate:

• Ideal temperature: 60-75°F (15-24°C). Within this range, curing time meets product specifications.

• Temperatures below 60°F (15°C): The reaction slows down, curing time is extended by 30%-50%, and the surface may become sticky while the interior softens.

• Temperatures above 75°F (24°C): The reaction accelerates, curing time is shortened, but excessive heat release may cause yellowing and deformation of the product.

• Humidity: Must be controlled below 85%. High humidity interferes with the curing reaction, causing surface fogging, reduced gloss, and even affecting adhesion.

（3） Product Formulation and Mixing Ratio

There are significant differences in the formulations of deep-poured epoxy resins from different brands, and their curing times also vary accordingly:

Rapid-curing type: Initial curing takes 24–36 hours, suitable for projects with tight schedules.
Standard slow-curing type: Initial curing takes 48–72 hours (e.g., Jinhua Resin products). It features lower exothermicity, making it ideal for thick-layer pouring and reducing the risk of cracking.
Mixing ratio: Most deep-poured epoxy resins follow a ratio of 2:1 or 3:1 (resin to curing agent, by volume). A ratio deviation exceeding 5% will severely impair the curing process, resulting in permanent tackiness or incomplete curing. It is essential to mix the components precisely in accordance with the product instructions and stir thoroughly (for at least 3–5 minutes), ensuring no residue adheres to the container walls or bottom.

3、Practical Operation Recommendations

Prioritize Following the Product Instructions: Curing times may vary across different brands. Prior to official construction, it is imperative to check the labeled “gel time”, “initial curing time” and “full curing time” on the product packaging, as these serve as the most accurate reference criteria.

Interval Between Multiple Pouring Layers: If the total thickness of the project exceeds 1 inch, it is recommended to pour in multiple layers with each layer controlled to a thickness of 0.5–1 inch. The interval between adjacent layers should be 24–48 hours (subject to the first layer being fully surface-dried and non-sticky to the touch).

Environmental Control: Maintain a clean, dry and well-ventilated working environment during curing to prevent dust adhesion. Meanwhile, stabilize the temperature at 60–75°F and avoid direct sunlight or proximity to heat sources.

Curing Test: After initial curing, the curing condition can be determined by a press test—press the edge of the product lightly with your finger; it is qualified if there is no indentation and no stickiness on the finger. After full curing, a hardness test can be performed (e.g., no scratches are left when scratched with a fingernail).

4、Summary

The curing time of deep-poured epoxy resin can be simplified as follows: under standard conditions (60–75°F (15–24°C) and a single-layer thickness of 0.5–1 inch), the initial curing takes 24–72 hours and full curing takes 5–7 days. If the ambient temperature is lower, the pouring thickness is greater, or a slow-curing product is used, the full curing time may be extended to 1–2 weeks.

The core principles are “follow product instructions + control environmental conditions + avoid one-time thick pouring” to ensure complete curing and compliance with performance standards.