Common Mistakes When Using Epoxy Resin

Updated on Mar 21, 2025

When working with epoxy resin, beginners can sometimes encounter frustrating results due to small but crucial errors. Here are the most common mistakes — and how to avoid them:

⚖️ Incorrect Resin-to-Hardener Ratio
One of the most important factors in using epoxy resin successfully is getting the mixing ratio right.

Always measure carefully using volume or weight as instructed by the manufacturer.
Using the wrong ratio can result in resin that doesn’t cure properly, remains soft or sticky, or never sets at all.

🌀 Insufficient Mixing
Even with the correct ratio, improper mixing can ruin a project.

Stir slowly and thoroughly for the recommended time.
Scrape the sides and bottom of your mixing cup as you go.
Consider double mixing: transfer the resin to a second cup and stir again to ensure complete blending.

🌬️ Working in Unsuitable Conditions
Environmental conditions can have a big impact on your outcome.

Work in a well-ventilated space to avoid fume buildup.
Avoid working in extreme temperatures (too hot or too cold).
High humidity can interfere with curing and cause blushing or surface imperfections.

💧 Adding Moisture or Contaminants
Moisture and dust are the enemies of epoxy resin.

Keep your workspace dry, clean, and dust-free.
Avoid using porous materials or moulds that may release trapped moisture.
Use clean, dry tools and containers for best results.

🫧 Ignoring Bubbles
Air bubbles are common, but they shouldn’t be ignored.

Bubbles can form during mixing or pouring.
Use a heat gun, torch, or even a straw to carefully remove them from the surface after pouring.
Work slowly and pour carefully to minimize air entrapment.

🧽 Improper Surface Preparation
A poorly prepared surface can lead to poor adhesion or a blotchy finish.

Clean your surface thoroughly — remove dust, oil, moisture, or debris.
Ensure it's completely dry before applying resin.

⏱️ Rushing the Process
Patience is key with epoxy resin.

Don’t rush the pouring, curing, or demoulding process.
Let the resin cure for the full recommended time — even if it feels hard to the touch.
Disturbing your project too soon can ruin the finish or weaken the structure.

📏 Overloading the Resin
Bigger isn’t always better.

Pouring too much resin at once can cause overheating, extended cure times, or even cracking.
Stick to the recommended pour depth for your resin product, and pour in layers if needed.

✅ Quick Tips for Success