Getting the ratio right is the single most important step in any resin project. Too much or too little hardener
and the resin will stay soft, sticky, or tacky no matter how long you wait. This guide covers the correct ratio
for every Craft Resin product and the two ways you can measure it.
Ratio by product
| Product | Mixing ratio (by volume) | Working time | Hard cure | Full cure |
|---|---|---|---|---|
| Arts & Crafts | 1 : 1 (Resin : Hardener) | 35–40 min at 23–25°C / 72–77°F | 24 h | 72 h |
| Table Top | 1 : 1 (Resin : Hardener) | 40 min at 23–25°C / 72–77°F | 36 h | 48 h |
| Deep Pour | 2 : 1 (Resin : Hardener) | around 1 hour at 20–25°C / 68–77°F | 24 h | 48 h |
| UV Resin | No mixing required — single component | Cures on demand under UV light | 1–3 min under lamp | 1–3 min under lamp |
| Silicone (mould making) | 1 : 1 (by weight) | 20–40 min | 3–5 h at 25°C | 3–5 h at 25°C |
"Hard cure" is the point where the surface feels dry to the touch. "Full cure" is when the resin has completely
finished reacting — wait for full cure before demoulding, food contact, or heavy handling, not just hard cure.
Measuring by volume (recommended, most accurate for beginners)
Use the marked lines on the mixing cups that come with your kit, or any two identical measuring cups. Fill
each container to the same line — for Arts & Crafts and Table Top that means equal parts resin and hardener;
for Deep Pour it means two parts resin to one part hardener. Measuring by volume with matched cups is the
method the ratio is designed around, and it's the most forgiving for new users.
Measuring by weight (if you use a kitchen or jewellery scale)
Because resin and hardener have slightly different densities, the weight ratio is not identical to the volume
ratio. If you prefer scales:
- Arts & Crafts: weigh 1 part resin to 0.885 parts hardener by weight.
- Silicone (mould making): 1 : 1 by weight — this one is already the same by weight and by volume.
- Table Top, Deep Pour, UV Resin: these product lines are specified by volume; if you'd like the equivalent by-weight figure for your specific kit, our support team can confirm it — reply to any conversation and we'll get you the right number.
Why the ratio matters
Epoxy resin cures through a chemical reaction between resin and hardener, not by air-drying like paint. If the
ratio is off in either direction, the reaction can't complete properly, and you'll end up with resin that stays
soft, bendy, or sticky even after the normal cure time has passed. There's no way to "add more hardener later"
to fix an already-mixed batch — if the ratio was wrong, the best option is usually to remove the piece and
start again with fresh, correctly measured resin.
Step-by-step
- Warm the bottles first if your workspace is cool — sit them in a bowl of warm (not hot) water for a few minutes, or place them a couple of feet from a low heater. Warm resin measures and mixes more accurately.
- Measure both parts to the same line or scale reading, using identical containers for resin and hardener.
- Mix slowly and thoroughly for at least 3–5 minutes, scraping the bottom and sides of your mixing cup as you go. Under-mixing is one of the most common causes of soft or sticky spots — see our Sticky or Soft Result article for troubleshooting.
- Pour into a clean container without scraping the sides of the mixing cup, since any unmixed resin clinging to the sides can end up in your project.
Related articles
- Sticky or Soft Result — Troubleshooting Incomplete Cure
- Bubbles — Why They Appear and How to Remove Them
- Arts & Crafts vs Deep Pour vs Table Top — Which to Choose?
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