How do I calculate a 4:1:1 mix ratio?

A 4:1:1 ratio means 4 parts paint, 1 part hardener, and 1 part thinner. Total parts = 4+1+1 = 6. To make 600ml total: Paint = (4/6)*600 = 400ml; Hardener = (1/6)*600 = 100ml; Thinner = (1/6)*600 = 100ml.

What is the mixing ratio for epoxy resin?

Most epoxy resins use a 1:1 or 2:1 ratio by volume. Always check the manufacturer's label. A 1:1 ratio means equal parts resin and hardener. A 2:1 ratio means twice as much resin as hardener (e.g., 100ml resin + 50ml hardener).

Does mixing by weight differ from mixing by volume?

Yes! Paint components have different densities. Hardener is often heavier than base coat. Most automotive mixing cups are calibrated for VOLUME. If mixing by weight (scale), you must use the specific gravity data from the TDS (Technical Data Sheet), not the volume ratio.

What happens if I add too much hardener?

Adding too much hardener (activator) can make the paint brittle, cause it to crack, or cure too fast (reducing pot life). Adding too little can prevent the paint from ever fully curing, leaving it soft or tacky.

What is a 2K paint mix?

2K stands for '2 Komponent' (German). It requires a hardener (activator) to cure chemically, unlike 1K paints which dry by evaporation. Common 2K ratios are 2:1, 3:1, or 4:1.

🎨 Paint Mixing Ratio Calculator

Calculate Exact Parts for Paint, Hardener & Thinner

Mixing Ratio Preset

Total Volume Needed

*Assuming mixing by volume (density=1)

Ratio (Parts)

Paint

Hardener

Thinner

🎨 Paint Mixing Guide

Getting the correct mixing ratio is critical for 2K (two-component) paints, epoxies, and automotive finishes. Incorrect ratios can lead to curing failures, peeling, or poor finish quality.

Common Mixing Ratios

4:1:1 - Standard for many automotive clear coats and base coats. (4 parts Paint : 1 part Hardener : 1 part Thinner/Reducer)
2:1 - Common for epoxy primers and some clear coats. (2 parts Paint : 1 part Hardener)
1:1 - Typical for epoxy adhesives and tabletop resins.
3:1 - Often used for high-build primers.

The Formula

To calculate the amount for each part:

Add all parts together to get Total Parts. (e.g., 4+1+1 = 6)
Divide Desired Volume by Total Parts to get the value of "1 Part". (e.g., 600ml / 6 = 100ml)
Multiply "1 Part" by the ratio number for each component.

💡 From Mike Ross, Auto Body Specialist (22 years):

"Always use a calibrated mixing cup if possible, but this calculator is a lifesaver when you need a specific amount (like 350ml) that doesn't line up with the lines on the cup. Also, remember: Paint first, then Hardener, then Thinner. Stir well after adding the hardener BEFORE adding the thinner to ensure proper chemical activation."

⚠️ Common Mistakes

1. Mixing by Weight vs Volume: Most automotive ratios (4:1:1) are by VOLUME. If you use a scale, you must account for density (hardener is usually denser). Unless you have the specific gravity data, stick to volume mixing cups.

2. Ignoring Pot Life: Once you add the hardener, the clock starts ticking. A 2K mix might only be sprayable for 30-60 minutes. Only mix what you can spray immediately.

3. "Eyeballing" It: "Close enough" doesn't work with chemical curing. A 10% error in hardener can ruin the finish.

Reviewed by Mike Ross

Certified Auto Body Technician & Painter, 22 years experience in automotive refinishing and custom painting.

🎨 Paint Mixing Guide

Common Mixing Ratios

The Formula

⚠️ Common Mistakes

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