How to stir your resin mix
Measuring the ratio correctly gets you halfway there — how you stir the mix afterward decides whether it actually cures all the way through. Under-mixing is one of the most common causes of soft, sticky, or tacky patches, even when the resin and hardener were measured correctly. This guide covers technique, how long you realistically have to work, and what to check before you pour.
Working time by product
How long you can spend stirring and pouring depends on the product and batch size.
| Product | Mix ratio | Working time | Notes |
|---|---|---|---|
| Arts & Crafts | 1:1 by volume | ~35 minutes (50g at 25°C) | Recommended batch up to 500ml |
| Table Top | 1:1 by volume | ~25 minutes (100g at 25°C) | Max 3mm per coat |
| Deep Pour | 2:1 by volume (resin:hardener) | ~1 hour | Mix in 2-3kg batches for large pours |
| UV Resin | Single component, no mixing | N/A | Cures in 60-120 seconds under a UV lamp |
| Silicone (mould making) | 1:1 by weight | 20-40 minutes | Cures in 3-5 hours at 25°C |
A larger mixed batch gives you less working time, not more — a bigger mass of curing resin generates heat faster, which speeds up the reaction. If you're mixing a big batch, don't slow down your stirring to compensate; work efficiently instead.
How to stir correctly
There's no single fixed stir time that works for every batch — it depends on volume, container shape, and how thorough your technique is. What actually matters is coverage, not the clock: keep working a flat-edged spatula around the sides, bottom, and corners of the container until the mix looks completely uniform, with no streaks, swirls, or cloudy patches anywhere.
For most Craft Resin products this takes a few minutes of continuous, deliberate stirring. Stir slowly rather than fast — whipping the mix introduces air you'll then have to deal with as bubbles. Stop only when you genuinely can't find a different-looking patch anywhere in the container, including right at the bottom edge, which is the spot people skip most often.
Why technique matters
Resin and hardener only cure properly where they've actually combined. A streak of unmixed resin or hardener left along the side or base of the container stays soft or tacky indefinitely — it won't finish curing no matter how long you leave it, because full cure time only applies to material that was mixed in the first place. This is a separate problem from under-curing due to cold temperatures or a wrong ratio, but it looks identical from the outside: a soft or sticky patch on an otherwise cured piece.
Because working time is limited and varies by product, the goal is thorough, not slow. Stirring "extra long to be safe" just eats into the time you have left to pour.
Step-by-step
- Warm cold resin first. Below 15°C, warm the resin (Part A) to around 30°C before you start. Cold resin is thicker and harder to mix completely.
- Measure by volume. Use graduated mixing cups for resin and hardener — equal weights are not equal volumes, since the two components have different densities. The one exception is silicone for mould making, which is measured 1:1 by weight.
- Combine both components in one clean container, rather than adding one directly into a mould that already has the other in it.
- Stir slowly, scraping constantly. Work the sides, bottom, and corners in a deliberate motion for the full time it takes to get a uniform mix — don't stir fast, and don't stop early.
- Check for clarity before you pour. Tilt the container toward the light and look for streaks or a different sheen anywhere in the mix. If you see any, keep scraping and stirring that spot specifically, then pour as soon as it's clear — your working time clock started the moment resin met hardener.
Related articles
- Mixing Ratio — How to Measure Resin and Hardener Correctly
- Sticky or Soft Result — Troubleshooting Incomplete Cure
- How to pour your resin mix
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