What is the typical resin mix ratio?

Most epoxy resins use a 2:1 ratio (2 parts resin to 1 part hardener), which is the most common. Some resins use 1:1 (equal parts), and specialty resins may use 3:1 or other ratios. Always check your specific resin's instructions - ratios vary by brand, type, and intended use. Using the wrong ratio prevents proper chemical reaction and curing. The ratio is usually printed on the product label or in the instructions. Never assume - always verify your resin's exact ratio.

Why is the mix ratio important?

The correct ratio is critical for proper chemical reaction between the resin and hardener. Too much or too little of either part disrupts the curing process. Incorrect ratios result in: sticky, tacky resin that never fully hardens; soft, flexible resin instead of hard; incomplete curing; or resin that cures but is weak and brittle. The ratio must be precise - even small errors (5-10%) can cause problems. Always measure accurately by weight (using a scale) or volume (using graduated containers) as specified by your resin manufacturer.

Should I measure by weight or volume?

Follow your resin manufacturer's instructions - some require weight measurement, others volume. Weight measurement (using a digital scale) is generally more accurate since resin and hardener may have different densities. Volume measurement (using graduated cups) works if your resin is designed for it. Never mix methods - if instructions say weight, use weight. If they say volume, use volume. Don't assume 1:1 by volume equals 1:1 by weight - densities differ. When in doubt, use weight measurement for accuracy.

What happens if I mix the ratio wrong?

Incorrect ratios cause curing problems: Too much hardener (part B) can cause: brittle, weak resin; excessive heat during curing; very short working time; or incomplete curing. Too little hardener can cause: sticky, tacky surface that never fully hardens; soft, flexible resin; very long or incomplete curing; or weak final product. Small errors (5-10%) may still work but result in suboptimal properties. Large errors (20%+) will likely prevent proper curing. If you realize the mistake immediately, you can sometimes add the correct amount, but it's better to start over with a fresh mix.

How long do I need to mix the resin?

Mix thoroughly for 2-3 minutes, scraping the sides and bottom of your mixing container. The goal is complete, uniform mixing - you shouldn't see any streaks or separate layers. Mix slowly and deliberately to minimize air bubbles. Some resins may require longer mixing times - check your specific product instructions. Under-mixing leaves unmixed portions that won't cure properly. Over-mixing (very vigorous, fast mixing) introduces excessive air bubbles. The key is thorough, slow, deliberate mixing until the mixture is completely uniform.

Can I mix different resin brands together?

No, never mix different resin brands or types together, even if they have the same ratio. Each resin formulation is designed to work with its specific hardener. Mixing brands can cause: incomplete curing, weak final product, color issues, or dangerous chemical reactions. Always use the resin and hardener from the same product line. If you need more resin, buy more of the same brand and type. Don't try to "match" ratios between different products - the chemical formulations are different even if ratios appear similar.

Resin Mix Ratio Calculator

Calculate exact mix amounts for part A and part B resin based on ratio.

Part A Ratio

Part B Ratio

Total Amount Needed (grams)

How This Tool Works

This calculator determines the exact amounts of part A (resin) and part B (hardener) needed based on your resin's specific mix ratio and the total amount of mixed resin you need. Epoxy resins require precise mixing ratios to ensure proper chemical reaction and curing. The ratio varies by resin type - common ratios include 2:1, 1:1, and 3:1 (part A to part B). Getting the ratio wrong can result in sticky, soft, or uncured resin that never fully hardens.

The calculator uses the ratio to proportionally divide your total needed amount. For example, with a 2:1 ratio and 300g total, you need 200g of part A and 100g of part B. Accurate measurement is critical - always measure by weight (using a digital scale) or volume (using graduated containers) as specified by your resin manufacturer. Some resins require weight measurement, others volume - always follow your specific resin's instructions for best results.

Formula

The mix amounts are calculated using:

Part A = (Total Amount ÷ (Part A Ratio + Part B Ratio)) × Part A Ratio
Part B = (Total Amount ÷ (Part A Ratio + Part B Ratio)) × Part B Ratio

Examples

2:1 ratio, 300g total: 200g Part A, 100g Part B (most common ratio)
1:1 ratio, 200g total: 100g Part A, 100g Part B (equal parts)
3:1 ratio, 400g total: 300g Part A, 100g Part B (some specialty resins)
2:1 ratio, 150g total: 100g Part A, 50g Part B (small project)
1:1 ratio, 500g total: 250g Part A, 250g Part B (large project)

Resin Mixing Best Practices

Measure Accurately: Use a digital scale (for weight) or graduated containers (for volume) - never estimate
Follow Instructions: Always use your specific resin's ratio - different brands/types have different ratios
Mix Thoroughly: Stir slowly and thoroughly for 2-3 minutes, scraping sides and bottom to ensure complete mixing
Mix in Clean Container: Use a clean mixing container - contaminants can affect curing
Work Temperature: Most resins work best at 20-25°C - too cold slows curing, too hot accelerates it
Mix Small Batches: For large projects, mix in smaller batches rather than one large batch (prevents overheating)
Work Time: Be aware of pot life (working time) - mix only what you can use within that time
Scrape Container: Scrape all mixed resin from container - leaving some behind wastes material

Common Resin Mixing Mistakes

Incorrect Ratio: Even small ratio errors can prevent proper curing - always measure precisely
Insufficient Mixing: Not mixing long enough leaves unmixed portions that won't cure properly
Mixing Too Fast: Fast, vigorous mixing introduces air bubbles - mix slowly and deliberately
Wrong Measurement Method: Using volume when weight is required (or vice versa) causes ratio errors
Contaminated Materials: Water, dust, or other contaminants can prevent proper curing
Temperature Issues: Mixing in too cold or too hot conditions affects curing and working time
Mixing Too Much: Large batches can overheat and cure too quickly - mix in manageable amounts
Not Following Instructions: Each resin brand has specific requirements - always read and follow instructions

FAQ

What is the typical resin mix ratio?
Most epoxy resins use a 2:1 ratio (2 parts resin to 1 part hardener), which is the most common. Some resins use 1:1 (equal parts), and specialty resins may use 3:1 or other ratios. Always check your specific resin's instructions - ratios vary by brand, type, and intended use. Using the wrong ratio prevents proper chemical reaction and curing. The ratio is usually printed on the product label or in the instructions. Never assume - always verify your resin's exact ratio.
Why is the mix ratio important?
The correct ratio is critical for proper chemical reaction between the resin and hardener. Too much or too little of either part disrupts the curing process. Incorrect ratios result in: sticky, tacky resin that never fully hardens; soft, flexible resin instead of hard; incomplete curing; or resin that cures but is weak and brittle. The ratio must be precise - even small errors (5-10%) can cause problems. Always measure accurately by weight (using a scale) or volume (using graduated containers) as specified by your resin manufacturer.
Should I measure by weight or volume?
Follow your resin manufacturer's instructions - some require weight measurement, others volume. Weight measurement (using a digital scale) is generally more accurate since resin and hardener may have different densities. Volume measurement (using graduated cups) works if your resin is designed for it. Never mix methods - if instructions say weight, use weight. If they say volume, use volume. Don't assume 1:1 by volume equals 1:1 by weight - densities differ. When in doubt, use weight measurement for accuracy.
What happens if I mix the ratio wrong?
Incorrect ratios cause curing problems: Too much hardener (part B) can cause: brittle, weak resin; excessive heat during curing; very short working time; or incomplete curing. Too little hardener can cause: sticky, tacky surface that never fully hardens; soft, flexible resin; very long or incomplete curing; or weak final product. Small errors (5-10%) may still work but result in suboptimal properties. Large errors (20%+) will likely prevent proper curing. If you realize the mistake immediately, you can sometimes add the correct amount, but it's better to start over with a fresh mix.
How long do I need to mix the resin?
Mix thoroughly for 2-3 minutes, scraping the sides and bottom of your mixing container. The goal is complete, uniform mixing - you shouldn't see any streaks or separate layers. Mix slowly and deliberately to minimize air bubbles. Some resins may require longer mixing times - check your specific product instructions. Under-mixing leaves unmixed portions that won't cure properly. Over-mixing (very vigorous, fast mixing) introduces excessive air bubbles. The key is thorough, slow, deliberate mixing until the mixture is completely uniform.
Can I mix different resin brands together?
No, never mix different resin brands or types together, even if they have the same ratio. Each resin formulation is designed to work with its specific hardener. Mixing brands can cause: incomplete curing, weak final product, color issues, or dangerous chemical reactions. Always use the resin and hardener from the same product line. If you need more resin, buy more of the same brand and type. Don't try to "match" ratios between different products - the chemical formulations are different even if ratios appear similar.