Resin Art Mixing Ratio Calculator
Calculate exact Part A (Resin) and Part B (Hardener) amounts for any ratio. Perfect for 1:1, 2:1, or 100:45 epoxy systems.
● Mixing Details
Common ratios: 1:1 (Deep Pour), 2:1 (Art Resin), 100:45 (Industrial). Check your bottle!
● Your Epoxy Mix
Enter your total amount and ratio, then hit "Calculate Mix" to get your precise measurements.
Part A (Resin)
0.00
ml
Part B (Hardener)
0.00
ml
Total Mixed Yield
0.00 ml
Mixing Tip:
Pour Part A into your mixing cup first, followed by Part B. Mix slowly for 3-5 minutes, scraping the sides and bottom of the cup to ensure a fully homogenous chemical bond.
How to Use the Resin Mixing Calculator
Using the Toolriz Resin Art Mixing Ratio Calculator is simple. Follow these four steps to ensure a perfect, bubble-free cure every time:
Select Measurement Type
Decide if you are measuring By Volume (using graduated cups) or By Weight (using a digital scale). Note: Weight is more accurate, but you must use the manufacturer's weight ratio, not their volume ratio.
Enter Total Amount Needed
Input how much total mixed resin you need for your project. If you don't know how much you need, a general rule for coating artwork is 1 oz of mixed resin per square foot (or 3 ml per 100 sq cm).
Input Your Ratio (A:B)
Check your resin bottle. If it says "2:1", enter 2 for Part A and 1 for Part B. If it says "100:45", enter 100 and 45. The calculator works with any epoxy, polyester, or polyurethane ratio.
Calculate & Mix
Click "Calculate Mix". The tool will tell you exactly how much Part A and Part B to pour. Measure Part A first, then add Part B, and mix thoroughly!
The Ultimate Epoxy Chemistry Masterclass for USA Artists
Resin art has taken the USA crafting community by storm. From ocean waves on charcuterie boards to deep-pour river tables, epoxy resin is a versatile and beautiful medium. However, epoxy is not like paint or water; it is a highly sensitive, two-part chemical thermoset. The difference between a crystal-clear, rock-hard finish and a sticky, bubbly, yellowed mess comes down to one thing: Stoichiometry (the exact chemical ratio).
If your ratio is off by even a few grams, the cross-linking polymer chains will not fully connect. This leaves unreacted resin or hardener in your artwork, resulting in a tacky surface that will never cure, no matter how long you wait. A ruined batch of resin isn't just frustrating; it can ruin a $100 piece of wood and waste hours of work. The Toolriz Resin Mixing Ratio Calculator is engineered to eliminate human error and ensure your chemical reactions go to completion.
1. The Critical Difference: Volume vs. Weight Ratios
The number one mistake USA resin beginners make is confusing volume ratios with weight ratios. Resin (Part A) and Hardener (Part B) have different chemical densities (Specific Gravity). Part A is generally heavier and denser than Part B.
- Volume Ratio: If a kit says "2:1 by volume", it means you need two identical measuring cups of resin for every one measuring cup of hardener. This is easy for artists using silicone graduated cups.
- Weight Ratio: If a kit says "100:45 by weight", it means you need 100 grams of resin for every 45 grams of hardener. Because resin is heavier, 100g of resin by weight looks completely different than 100ml of resin by volume.
Dangerous Cross-Mixing: Never use a volume ratio on a digital scale, and never use a weight ratio in a measuring cup. If your bottle says "100:45 (Weight)" but you try to measure 100ml and 45ml, your resin will fail to cure. Always use the Toolriz calculator in the correct mode.
2. Exothermic Reactions and "Flash Curing"
When Part A and Part B mix, a chemical reaction occurs that generates heat. This is called an exothermic reaction. The heat helps the molecules move and bond together.
If you mix too much hardener (off-ratio), the reaction accelerates violently. The mixture can reach temperatures over 400°F in minutes, causing the resin to yellow instantly, boil with massive bubbles, crack from the inside, or even melt through a plastic solo cup. This is known as "flash curing." Always mix the exact amounts given by the Toolriz calculator, and never mix more than the manufacturer's maximum batch size (usually 1-2 gallons for standard art resin, less for deep pour).
3. The Three Stages of Epoxy Curing
Understanding the curing process is vital for USA artists who want to manipulate their resin (e.g., dirty pours, lacing, or torching). Epoxy doesn't just "dry" like paint; it transitions through distinct chemical phases.
- Liquid Phase (Working Time): This is the "pot time" or "working time" (usually 30-45 minutes for art resin). The mixture is thin, and the chemical reaction is just beginning. You can pour, manipulate, and torch bubbles during this phase.
- Gel Phase (B-Stage): The resin thickens to the consistency of honey, then gelatin. The cross-linking is accelerating. You can no longer manipulate the resin or pop bubbles. If you touch it, it will leave a permanent fingerprint.
- Solid Phase (Tack-Free): The resin is hard to the touch. However, a full chemical cure takes much longer. While it may feel solid at 12 hours, it takes 72 hours to reach maximum hardness and chemical resistance. Do not sand or coat it until 72 hours have passed.
4. Pigments, Inks, and Interference Ratios
Adding color to resin is fun, but pigments are not chemically neutral. They can interfere with the stoichiometry (the A:B ratio) of your mix.
- The 10% Rule: Never add more than 10% of your total mixed volume in pigment. If you have 100ml of mixed resin, do not add more than 10ml of liquid pigment. Adding too much alcohol ink or acrylic paint can throw off the chemical balance, causing the resin to cure bendy or sticky.
- Mica Powders: Mica is generally inert and does not interfere with the cure. However, adding too much mica can make the resin clumpy and weaken its structural integrity.
- Alcohol Inks: Alcohol inks are highly concentrated. A few drops are all you need. Because alcohol evaporates, it can cause micro-bubbles in your resin. Always torch lightly to remove them.
5. USA Safety Standards: VOCs and PPE
Epoxy resin is a sensitizer. Repeated exposure to uncured resin can lead to allergic contact dermatitis. In the USA, the EPA and OSHA regulate the handling of these chemicals.
- Ventilation: Always mix and pour epoxy in a well-ventilated area. Uncured resin emits Volatile Organic Compounds (VOCs) which can cause respiratory irritation.
- Nitrile Gloves: Never touch resin with bare hands. Use nitrile gloves (not latex, as resin dissolves latex).
- Respirators: If you are working with industrial epoxies or sanding cured resin (which creates toxic silica dust), wear an OSHA-approved respirator with organic vapor cartridges (like the 3M 60921).
Frequently Asked Questions (FAQ)
What happens if I put too much hardener in my epoxy mix?
If you add too much Part B (Hardener), the chemical reaction will accelerate violently, causing an extreme exothermic reaction. The resin will likely yellow rapidly, generate massive bubbles, shrink, crack internally, and may even melt your mixing cup. The cured piece will be brittle and unusable. Always use the Toolriz calculator to measure exactly.
What happens if I put too much resin (Part A) in my mix?
If you add too much Part A (Resin), there will not be enough hardener to trigger the cross-linking reaction. The mixture will remain permanently liquid or develop a sticky, tacky surface that never fully cures. Unfortunately, you cannot just "paint more hardener" on top; the entire batch must be scrapped and remeasured.
Can I mix a 2:1 resin kit by weight instead of volume?
No, unless the manufacturer explicitly provides a weight ratio. Because Part A and Part B have different densities, a 2:1 volume ratio is mathematically different from a 2:1 weight ratio. If you try to measure 200 grams of Part A and 100 grams of Part B (for a 2:1 ratio), you will likely be off-ratio, and the resin may not cure. Use the Toolriz calculator in "By Weight" mode only if you know the exact weight ratio (e.g., 100:45).
How do I calculate how much mixed resin I need for my painting?
For coating artwork (like a canvas or wooden panel), the standard rule in the USA is 1 fluid ounce of mixed resin per square foot (or roughly 3 ml per square foot). Measure your canvas in inches, multiply Length x Width, and divide by 144 to get square feet. Multiply that by 1 oz to get your total needed mixed resin. Enter that number into the calculator!
Why is my resin still sticky after 24 hours?
If your resin is sticky after 24 hours, you either measured off-ratio, did not mix long enough, or your room temperature is too cold. Epoxy requires a minimum ambient temperature of 70°F (21°C) to cure properly. If your room is 60°F, the chemical reaction slows drastically. Move the piece to a warmer room, or use a heat lamp to gently warm the surface.
How long should I mix my resin?
You should mix epoxy resin for a minimum of 3 to 5 minutes, depending on the batch size. Use a flat wooden stir stick (not a round spoon) to scrape the sides and bottom of the cup continuously. If you don't scrape the sides, unmixed resin will pool on your artwork and leave permanent wet, sticky spots. The mixture should turn perfectly clear with no streaks.
Can I use a heat gun or torch to remove bubbles from my resin?
Yes, but only during the Liquid Phase (working time). A butane torch or heat gun briefly reduces the surface tension of the resin, allowing trapped air bubbles to rise and pop. Sweep the flame quickly across the surface—do not hold it in one spot, as this can scorch the resin or cause premature yellowing. Never use a torch after the resin has entered the Gel Phase.
What is the difference between deep pour resin and coating resin?
Coating resin (often a 1:1 or 2:1 ratio) is designed for thin pours (1/8 inch to 1/4 inch thick). It cures hard and fast, generating significant heat. Deep pour resin (often a 2:1 or 3:1 ratio with a slower hardener) is formulated to pour in layers up to 2 inches thick without generating a dangerous exothermic reaction. Deep pour resin takes much longer to cure (up to 7 days) but prevents cracking and yellowing in thick blocks.