Creating resin coasters is a fun and rewarding craft, but like any art form, it comes with a learning curve. Beginners often run into a few common issues that can lead to frustration or wasted materials. The good news is that most mistakes are easy to avoid with a bit of knowledge and preparation. Whether you’re just getting started or want to improve your technique, understanding these typical pitfalls will help you create beautiful, functional coasters from the very first pour.
1. Incorrect Resin Mixing Ratios
One of the most common mistakes is getting the resin-to-hardener ratio wrong. Most epoxy resins are formulated to be mixed in a precise 1:1 or 2:1 ratio, and even a small deviation can affect the curing process. If the mixture is off, it might stay sticky, remain soft, or never fully cure—ruining your piece.
How to avoid it:
Always read the manufacturer’s instructions carefully, as different brands have different requirements. Use separate, clearly marked measuring cups for resin and hardener, and measure by volume unless weight is specifically indicated. Mix thoroughly—scraping the sides and bottom of the container—to ensure the two components are fully combined.
2. Trapped Bubbles
Bubbles are almost inevitable when mixing resin, but if not properly dealt with, they can create cloudy spots or uneven surfaces in your coasters. They may also rise to the surface and harden into unwanted texture.
How to avoid it:
Mix your resin slowly to minimize bubble formation. After pouring, use a heat gun or a torch (held at a safe distance) to pop surface bubbles. You can also let the resin sit for a few minutes after mixing to allow air to escape before pouring. If you’re embedding objects like flowers or glitter, be especially mindful of trapped air underneath.
3. Pouring Too Thick or Too Fast
Many beginners assume that a deeper pour will give them better results, but pouring resin too thick can cause excessive heat buildup, warping, or cracking as it cures. It may also prevent the center from hardening fully, especially in high-gloss molds like coasters.
How to avoid it:
Check your resin’s recommended pour depth and stick to it. If you want a thicker coaster or layered effect, pour in stages, allowing each layer to partially cure before adding the next. This also gives you more control over color placement or embedded items.
4. Dust and Debris in the Resin
Few things are more disappointing than finishing a perfect pour and discovering tiny dust particles or hairs stuck in the surface after curing. Resin is extremely sticky and will attract airborne debris during the curing process, especially in busy or poorly ventilated areas.
How to avoid it:
Work in a clean, dust-free space. After pouring, cover your molds with a plastic container or acrylic lid to protect the resin while it cures. Wipe down your tools and surfaces beforehand, and avoid wearing lint-prone clothing. You can also run an air purifier in the room before starting to reduce floating dust.
5. Removing Coasters from the Mold Too Early
It’s tempting to demold your coasters as soon as they feel firm, but pulling them out too early can result in warped shapes, fingerprints, or a tacky finish. Some resins may feel set after 12 hours, but they continue curing for up to 72 hours.
How to avoid it:
Be patient and let the resin cure fully according to the product instructions. If you plan to sand or polish your coasters, make sure they’re completely hardened to avoid smearing or scratching the surface. Keep in mind that environmental factors like temperature and humidity can also affect cure times.