Why Is My Epoxy Resin Still Sticky or Not Curing Properly?
1. Incorrect Mixing Ratio
This is the number one reason resin stays sticky or soft.
1:1 epoxy resin must be mixed in equal parts by volume (Part A resin : Part B hardener = 1:1).
If there’s too much of Part A, it will never cure fully. Too much Part B can make the resin brittle or overheat.
Using a kitchen scale can be misleading — most 1:1 resins are meant to be mixed by volume, not by weight.
Tip: Always use a measuring cup with clear markings and pour carefully at eye level.
2. Incomplete Mixing
Even if your ratio is perfect, improper mixing can ruin the reaction.
Mix slowly and thoroughly for at least 3–5 minutes.
Scrape the sides and bottom of your mixing cup frequently.
If the resin is not fully blended, some parts won’t react and will stay tacky forever.
Pro Tip: Try the double-cup method — after mixing, pour everything into a second clean cup and mix again for another minute.
3. Low Temperature or High Humidity
Epoxy resin is temperature-sensitive.
The ideal working temperature is 25°C–30°C (77°F–86°F).
In cold rooms, the chemical reaction slows down dramatically, leaving the resin soft or uncured.
High humidity can also interfere with curing and cause a cloudy or sticky surface.
Solution: Work in a warm, dry, and dust-free environment. If your resin didn’t cure properly, move it to a warmer area (but don’t overheat it).
4. Premature Touching or Moving
Resin takes time to harden.
Avoid touching or moving your project during the first 24 hours.
Even if it seems hard on top, the inner layers may still be soft.
Full cure can take up to 72 hours depending on thickness and temperature.
Tip: If your resin is still tacky after 24 hours, leave it another day in a warm room. Sometimes patience is all it needs.
5. Wrong Product Combination
Not all resins and hardeners are interchangeable.
Mixing different brands or formulas can prevent proper chemical reaction.
Always use the resin and hardener from the same kit and brand.
Suzzam Tip: Our 1:1 Epoxy Resin is formulated for balanced curing and clear finish — never mix with other systems.
6. Contaminated Tools or Materials
Residue from old resin, water, or alcohol can disrupt curing.
Make sure cups, sticks, and molds are completely clean and dry before use.
Avoid using silicone molds with leftover oil, release agent, or dust.
Pro Tip: Wipe molds with alcohol and let them dry fully before pouring.
7. Storage or Shelf-Life Issues
Old or improperly stored resin can lose reactivity.
Keep both bottles tightly sealed in a cool, dry place (15°C–25°C / 59°F–77°F).
Avoid extreme heat, cold, or direct sunlight.
If your resin has crystallized or turned cloudy, warm it gently before use.
How to Fix a Sticky Resin Project
If you’ve already poured and it’s sticky:
Scrape off any wet or tacky areas.
Clean the surface with isopropyl alcohol.
Recoat with a fresh, correctly mixed batch of resin.
This will seal and cure the surface properly.
Final Thoughts
Sticky or soft resin can be frustrating — but it’s also a valuable learning experience.
By controlling your mixing ratio, temperature, and environment, you’ll dramatically improve your success rate and enjoy a clear, glassy finish every time.
✨ Suzzam 1:1 Epoxy Resin is designed for easy mixing, strong curing, and long-lasting clarity — perfect for beginners and professionals alike.