5 Common Resin Mistakes & How to Fix Them

📅 Dec 11, 2024 ⏱️ 8 min read ✍️ Keith

Avoid the most common mistakes that ruin resin projects. Learn what causes them and exactly how to fix each one for perfect results every time.

We've all been there—you pour beautiful resin, and something goes wrong. Bubbles appear. It stays sticky. Colors look muddy. The frustration is real.

Here's the good news: most resin mistakes are completely preventable once you know what causes them. In this post, I'm breaking down the 5 most common mistakes I see (and have made myself) plus the exact fix for each one.

Mistake #1: Not Using a Digital Scale

❌ The Problem
Eyeballing Your Resin Ratio

This is hands-down the most common mistake. People think "close enough" works for epoxy resin. It absolutely does not.

When you eyeball your ratio (especially if your instructions say 10:1), you're creating incomplete polymerization. Some resin doesn't have enough hardener to cure. Some hardener can't find resin to react with. Result: sticky, incomplete curing.

✅ The Fix:
Get a digital scale (they cost $20-30)
Weigh resin precisely (not "about this much")
Weigh hardener precisely (to the gram if possible)
Write down your exact numbers each time
If you have sticky resin, it's almost always ratio—throw it out and start over with scale

Pro tip: This single change fixes 80% of resin problems. Seriously. Get the scale.

Mistake #2: Vigorous Mixing (Creating Tons of Bubbles)

❌ The Problem
Beating Your Resin Like You're Making Pancakes

Fast mixing introduces air into resin. You whip it around, create air pockets, and those bubbles stay trapped forever once cured.

I see this constantly—people mixing resin with high-speed drills or whisking it rapidly. Then they're shocked when their piece looks frosted.

✅ The Fix:
Mix SLOWLY—imagine you're stirring honey, not making a milkshake
Use low-speed drill mixer (if using power tools) or hand stir slowly
Stir for 2-3 minutes thoroughly, focusing on the sides and bottom
After mixing, let resin REST for 30-60 seconds—bubbles naturally rise to surface
Use a heat gun briefly if you still see surface bubbles (20-30 seconds max)

Pro tip: Slow mixing is better than any bubble removal technique. Prevention beats cure.

Mistake #3: Pouring Into a Mold Without Release Agent

❌ The Problem
Resin Stuck Permanently in Mold

You finish your beautiful piece, go to demold... and it won't come out. It's bonded to the mold forever. The frustration is brutal.

This happens because resin doesn't naturally release from every mold material. Metal, glass, plastic—they're all problematic without release agent. Even some cheap silicone molds stick without it.

✅ The Fix:
Quality silicone molds (platinum-cure) sometimes don't need release agent, but using it doesn't hurt
For ANY non-silicone mold, release agent is mandatory
Apply release agent 10-15 minutes BEFORE pouring
Let it dry completely—if it's wet when you pour, it won't work
Use resin-specific release agent (PVA spray or silicone spray, not cooking spray)
Apply generously—thin coat misses spots, thick coat prevents bonding

Pro tip: Spend 2 minutes on release agent prep and avoid 2 hours of demolding frustration.

Mistake #4: Using Non-Resin Pigments or Cheap Dyes

❌ The Problem
Colors Bleed, Fade, or Look Muddy

You buy cheap "resin dye" from a general craft store, mix it in, and the color either bleeds into the clear resin (creating a halo effect), fades immediately, or looks dull and muddy.

This is because you didn't buy resin-specific pigments. Food coloring, acrylic paint, fabric dye—none of these are formulated for epoxy chemistry. They're chemically incompatible.

✅ The Fix:
Only buy pigments labeled "resin-specific" or "epoxy-specific"
Buy from resin suppliers, not general craft stores
Quality pigments cost $3-8 and last forever
Mica powders are excellent and won't bleed
Liquid epoxy dyes are easy to mix and prevent settling
If you already have the wrong pigments, toss them and start over

Pro tip: Your beautiful piece deserves quality pigments. Save money elsewhere.

Mistake #5: Not Letting Resin Cure Long Enough Before Demolding

❌ The Problem
Piece Cracks or Won't Demold

You're excited. You demold at 12 hours instead of waiting 24. Resin is still slightly flexible, and pieces either don't come out cleanly or snap during removal.

This is a chemistry issue—epoxy needs time for molecular polymerization to complete. At 12 hours, it's mostly hard. At 24-48 hours, it's fully hard and shrunk slightly, making demolding easier.

✅ The Fix:
Wait MINIMUM 24 hours before demolding (48 hours is better)
In cold environments (below 70°F), wait extra time—reaction is slower
The extra waiting prevents cracks, makes demolding easier, gives better final hardness
If piece is sticky at 24 hours, wait another 24—it's not fully cured yet
When you do demold, go slow—flex mold gently, don't force

Pro tip: Patience is free. Rushing costs you finished pieces. Be patient.

The Common Thread

Notice what connects these five mistakes? They're all about precision and patience. Use a scale (precision). Mix slowly (precision). Use the right materials (precision). Wait long enough (patience).

Master those two things—precision and patience—and you'll avoid 90% of resin problems. Seriously.

Your Action Plan

Here's what to do right now:

  1. Get a digital scale if you don't have one. This is your #1 priority. $25 solves most problems.
  2. Buy resin-specific pigments. Toss the craft store dyes. Quality pigments last forever and cost very little.
  3. Practice slow mixing and patience. Set a timer for 24 hours before demolding. You'll be amazed at the difference.
  4. Use release agent on every non-silicone mold. It costs a few dollars and saves hours of frustration.

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