Sticky or Soft Result — Troubleshooting Incomplete Cure

If your resin is still soft, bendy, or tacky well past its expected cure time, the cause is almost always one
of two things: an inaccurate ratio, or incomplete mixing. Neither can be fixed after the fact by "adding more
time" — the good news is both are easy to avoid next time.

Check the cure time first

Before troubleshooting, confirm you've actually passed the full cure time for your product — hard cure (when
the surface feels dry) and full cure (when the resin has completely finished reacting) are different
milestones. See the cure times per product in our Mixing Ratio article. A piece that's merely tacky a few
hours after pouring may simply still be within its normal working or hard-cure window.

Most common cause: inaccurate measuring

Uneven amounts of resin and hardener are the single most common reason for a sticky or soft result. A few
questions to check:

• Did you measure both components to the exact same line, using identical containers?
• If using a scale, did you use the correct by-weight ratio for your specific product (not just eyeballing it)?
• Were the bottles evenly filled to begin with, or was one already lower before you started?

If you consistently end up with more of one component than the other, switching to a scale (or double-checking
your cups are truly identical) usually resolves it. Our support team is happy to help you pin down where the
measurement is going wrong if it keeps recurring.

Second most common cause: under-mixing

If the ratio was correct but the result is still sticky, incomplete mixing is the likely culprit.

• Stir for at least 3–5 minutes, not just until the mixture looks combined — resin and hardener need sustained mixing to fully react, not just visual blending.
• Scrape the bottom and sides of the mixing cup repeatedly while stirring. Resin and hardener that cling unmixed to the container walls can end up in your pour and cause localised soft spots.
• When pouring into your project, don't scrape the mixing cup — any unmixed residue on the sides is best left behind, not poured out.

Other contributing factors

• Cold workspace: temperatures below the ideal range slow and can incompletely trigger the cure reaction. Keep your workspace within the ideal range for your product.
• Humidity: very humid conditions can interfere with a clean cure and contribute to a sticky surface film (see our Cloudy or Milky Result article for the related amine blush effect, which is different from an uncured sticky surface).

If a piece won't cure

If you've confirmed the ratio and mixing were correct and the piece still hasn't cured properly, get in touch
with our support team with details on your measuring method, mixing time, and workspace temperature —
we'll help you figure out what happened and how to avoid it next time.

Related articles

• Mixing Ratio — How to Measure Resin and Hardener Correctly
• Cloudy or Milky Result — Causes and Fixes
• Bubbles — Why They Appear and How to Remove Them