What the ratio means
The ratio is resin to hardener by volume. A 1:1 kit uses equal parts. A 2:1 kit uses two parts resin to one part hardener. Both cure hard; the difference is working time, pour depth and how forgiving the mix is.
1:1 kits
- Easier to measure: equal parts, often marked on the bottle.
- Faster gel time, usually 30 to 60 minutes.
- Designed for thin coats such as table tops and bar tops.
- Less sensitive to small measuring errors.
2:1 kits
- Longer working time, which suits large surfaces.
- Formulated for thick casts and deep pours.
- More sensitive to ratio errors: off by 10% and the cure can stay tacky.
- Better for river tables and moulds.
How to measure accurately
Use two clear cups and a scale or printed marks, and measure hardener first. Scrape every drop. For 2:1 kits, a small kitchen scale is more reliable than eyeballing volumes.
Which one for your project
Table tops, coasters and small coatings: 1:1. River tables, thick moulds and castings over 1 inch: 2:1 deep pour. If you are unsure, match the kit to the pour depth on the label rather than guessing.
Frequently asked questions
Can I use a 2:1 hardener with a 1:1 resin?
No. Kits are formulated as a pair; mixing brands or ratios gives an uncured or brittle result.
What happens if I add too much hardener?
More hardener does not mean faster cure. It usually means a softer, tacky or brittle finish.
Why did my 2:1 kit stay sticky?
Usually a measurement error or incomplete mixing. Scrape the cup walls and bottom while stirring.
Related reading
Compare 1:1 table top kits and 2:1 deep pour kits.
