Resin to Hardener Ratio Calculator
Calculate two-part resin batches by weight or volume, including density conversion, pigment loading, waste, batch splitting, temperature-adjusted pot life, and a per-batch mix sheet.
⚙Resin system presets
Choose a real-world style preset, then adjust the ratio printed on your product label. Different brands use different bases, so the ratio basis matters.
🧪Batch inputs
Mixing breakdown
⚖Resin system comparison grid
📋Ratio reference table
| Resin system | Typical ratio | Common basis | Density note | Typical use |
|---|---|---|---|---|
| Tabletop art epoxy | 1:1 | Volume | Similar densities | Coating and small pours |
| Deep pour casting epoxy | 2:1 | Volume | Hardener often lighter | River tables and molds |
| Marine laminating epoxy | 5:1 | Weight | Use scale for accuracy | Fiberglass wet-out |
| Carbon infusion epoxy | 100:30 | Weight | Low-viscosity resin | Vacuum infusion |
| Polyester with MEKP | 100:1.5 | Weight | Catalyst is small mass | Fiberglass repair |
| Gelcoat with MEKP | 100:2 | Weight | Temperature sensitive | Mold surface coat |
🌡Temperature and pot life table
| Shop temperature | Approx. pot life effect | Batch strategy | Mixing caution |
|---|---|---|---|
| 10°C / 50°F | About 2x longer | Warm resin first | Viscosity may trap bubbles |
| 18°C / 64°F | About 1.3x longer | Normal batches | Check minimum cure temp |
| 23°C / 73°F | Data sheet baseline | Use listed pot life | Start timer after combining |
| 30°C / 86°F | About 0.6x shorter | Split into smaller cups | Exotherm rises quickly |
| 35°C / 95°F | About 0.4x shorter | Mix very small batches | Avoid deep mass in cup |
🎨Pigment and additive limits
| Additive type | Typical loading | Measure by | Risk if too high |
|---|---|---|---|
| Liquid epoxy tint | 1% to 3% | Mixed mass | Soft cure or streaking |
| Mica powder | 2% to 6% | Mixed mass | Thick mix and poor flow |
| Opaque paste pigment | 3% to 10% | Mixed mass | Cure inhibition |
| Alcohol ink | Under 2% | Drops or mass | Bubbles and weak surface |
| Filler powder | 10% to 50% | Mixed mass | Shorter working time |
📏Mixing method checklist
| Method | Best for | Accuracy note | Common mistake |
|---|---|---|---|
| Digital scale | Weight ratios | Tare each cup | Forgetting pigment mass |
| Graduated cup | Volume ratios | Read at eye level | Using weight ratio by volume |
| Metered pumps | Repeat shop batches | Prime both pumps | Partial pump strokes |
| Syringe dosing | Small catalyst amounts | Use fine graduations | Air pockets in syringe |
ℹPractical tips
Achieving the correct ratios between the resin and the hardener are a necessary step to ensure the success of the project. An incorrect ratio between the two components will lead to the failure of the resin system. If a person adds too many resin or too much hardener to the resin system, the resulting product will not reach it’s full strength.
Additionally, the resin and the hardener may cure in a way that is too soft for the project requirements, or the resin and hardener may generates too much heat during the curing process, leading to cracking of the cured product. A successful project, therefore, requires that the person accurately measure both the resin and the hardener in gram or milliliters before adding the components to the mold. The resin systems requires a specific ratio of resin to hardener because the chemical reaction between the two components is not flexible to alterations in there relative amounts.
How to Measure and Mix Resin and Hardener
For instance, if the resin and hardener system requires a 2:1 ratio of the two components by volume, it is necessary to use twice as much hardener then resin by volume. If a person chooses to measure these components by weight instead of volume, the individual may create an incorrect ratio of resin to hardener. The calculator included with the article can assist the person who intends to use such a resin and hardener system to accurately manage these different types of measurement.
The temperature at which the person intends to utilize the resin and hardener will affect the working time of the components while they are in their uncured state. If the workspace in which the person will mix the resin and hardener is ten degrees warmer then the temperature recommended by the manufacturer, the pot life of the resin and hardener will decrease by almost half. An individual calculator allow the user to enter the temperature at which they will work in the shop so that the calculator can provide the realistic life of the resin and hardener once they are mixed.
The realistic pot life will allow a person to decide whether the resin and hardener should be pour into one large batch or divided into multiple batches to work with. In addition to the measurements of the resin and the hardener, an individual must also account for waste. Some of the resin and hardener will remain in the mixing cup and on the spatula used to mix the two components.
Additionally, if a person intends to load the cured resin and hardener with pigment, the pigment will add to the total volume of the resin system. A waste allowance percentage is included in the calculator to account for the loss of resin and hardener that will occur during these steps. If a person chooses to ignore the waste allowance percentage, they may find themselves out of resin and hardener prior to complete there project.
The percentage of pigment to be loaded into the resin and hardener system need to be calculated in addition to the resin to hardener ratio. Liquid tints are measured as a percentage of the total weight of the resin and hardener. An excessive amount of pigment will reduce the ability of the resin and hardener to achieve its full hardness.
Additionally, using too much pigment can lead to streaks within the cured resin. The calculator will display the percentage of liquid tint so that the user can avoid adding too much pigment to the resin and hardener system. An individual can use a batch splitting technique to allow individuals to reduce the amount of heat generated by the resin and hardener system and to extend the working time of the uncured resin and hardener.
A batch of resin and hardener will generate more heat than a group of smaller batch of resin and hardener. This heat will shorten the working time of the uncured resin and hardener. An individual can use the calculator to enter the number of batches into which they intend to divide the resin and hardener.
The calculator will divide the amount of resin and hardener into these separate batches so that an individual can split the batches and pour them into mold prior to them curing. Resin systems can use either the weight or the volume of the resin and hardener to indicate how much of each component should be used in a project. For instance, marine laminating epoxies may be measured by weight because the hardener is lighter than the resin.
In art epoxy systems, the resin and hardener components has similar densities so measuring them by volume is accurate enough for the art projects. The environment in which an individual plans to mix the resin and hardener may not reach the recommended temperature for that resin system. An individual may be working in a garage in the winter or on a kitchen table in the summer.
An individual can enter an allowance for the environmental temperature on the calculator so that an individual can accurately prepare for the setting in which they will perform their resin project. The chemistry of the resin and hardener will only work if the individual measure the resin and hardener according to the specifications included on the label of the manufacturers package.
