How to Fix Epoxy Mistakes

The popularity of epoxy resin in DIY projects has skyrocketed in recent years. Epoxy can be used to create custom countertops, unique insulated tumblers, to fill imperfections in wood, and more. There are numerous challenges to working with epoxy. Follow the steps below to address your epoxy mistakes.

Types of Epoxy

There are three common types of epoxy: polyester resin, epoxy acrylates, and pure epoxy. These three types of epoxy have unique characteristics and are best suited for certain projects. Most projects completed at home will use two-step pure epoxy, therefore two-step pure epoxy will receive the bulk of the attention.

Pure Epoxy

Pure epoxy is commonly used in woodworking and craft projects. There are two main varieties of pure epoxy: one-step and two-step epoxies. One-step epoxies are ready to use immediately. This type is less common, less customizable, and often weaker than two-step epoxies. 

The most common type of pure epoxy is two-step epoxy. This type requires epoxy resin and a hardening agent. There are many additives to this type of epoxy such as color, catalysts, fillers, and more. Two-step epoxies must be mixed correctly and allowed to cure completely, otherwise a variety of imperfections and problems can arise.

Epoxy Acrylate

The epoxy acrylate blends features of polyester resin and pure epoxy together. Epoxy acrylate hardens more quickly than pure epoxy and forms a stronger, hardier resin. It is also possible to have a low VOC formula of this epoxy which is ideal for use at home. 

Learn the differences in epoxy and polyurethane as a finisher.

How to Fix Epoxy Mistakes

While preparing, mixing, or curing epoxy, many mistakes can occur. Addressing many of the possible mistakes made during these three steps are outlined below beginning with the mixing process. 

1. Poor Epoxy Preparation Errors

Incorrectly preparing your work area is the source of many epoxy errors. For epoxy to bond well to any surface, the surface must be free of dust, oil, and contaminants. Wearing gloves and using denatured alcohol to clean surfaces is a great preparation strategy. Make sure all surfaces are dry before pouring your epoxy.

Pinholes, Fish Eyes, and Bubbles

Pouring epoxy usually requires at least two layers of epoxy, beginning with a seal. If surfaces are not properly prepared, poorly poured seal coats are the result. Contaminants on your work surface and your work environment can allow dimples, pitting, fisheyes, and bubbles to occur.

Epoxy will not adhere to oily surfaces. The oil naturally occurring on your skin can prevent epoxy adhesion. When resin only partially adheres, it allows dimples, pitting, and fisheyes. These occur when part of the epoxy adheres to your work surface while other sections of the epoxy are able to lift.

Moisture within wood will naturally offgas as the wood ages. If seal coats improperly adhere, offgas from the wood results in air trapped between epoxy and wood or air bubbles forming within wet epoxy. Properly prepared surfaces are the key to preventing these mistakes.

To fix pinholes, fisheyes, and bubbles in wet epoxy resin:

1. Return to your initial pour after 10 minutes.
2. Look for surface imperfections or contaminants. Because pours should rarely exceed 1/2 inch in depth, obvious contaminants can be safely removed using tweezers or a lint-free cloth.
3. Because you should always mix slightly more resin than necessary to complete your project, pour some of your remaining resin to fill pinholes, fisheyes, and dimples.
4. Allow gravity to flatten the newly added resin.
5. Leave the area to allow the resin to cure without the potential for stirring up contaminants. 

If you have pinholes, fisheyes, or bubbles  within cured epoxy resin:

1. Lightly sand the surface of the resin.
2. Wipe away resin particles with moistened lint-free cloth.
3. Allow the surface to completely dry.
4. Spray epoxy resin mold boards with cooking spray. Be sure not to get spray on the surface which will receive the new layer of epoxy resin.
5. Level and secure mold around the project.
6. Mix enough epoxy resin to overflow the mold you have created. Mix according to manufacturer instructions.
7. Pour epoxy resin allowing mixture to overflow the mold slightly.
8. Allow resin to harden before demolding. TIme varies depending on epoxy resin used. Follow manufacturer instructions.

Tip: Wet epoxy resin can chemically bond with an additional layer of freshly poured epoxy resin. On the other hand, cured resin must be roughed up through sanding in order to allow epoxy resin to mechanically bond to the existing layer. The freshly poured epoxy enters into the grooves created by sanding and hardens in those grooves similar to how velcro’s loops and hooks.

Ripples and Waves

Unless lumber is planed extremely evenly, the waviness of the wood can be revealed by a thin layer of epoxy. To prevent ripples and waves, apply thin layers of resin until ripples are not present. 

Alternately, heat is often applied to epoxy resin soon after pouring to encourage bubbles to rise to the surface by further softening the epoxy. Too much heat on the resin can result in waves. Be sure to avoid overheating your epoxy resin.

2. Epoxy Mixing Problems

Incorrectly mixed epoxy results in a host of issues. Common issues include epoxies hardening too quickly, too slowly, and not at all. The usual culprit in all of these problems are incorrect ratios of epoxy resin and hardening agent. 

Each brand of epoxy and application-specific epoxy will have its own instructions. Some epoxies are intended to act as a glue to powerfully connect surfaces, while others are meant to be cast into molds to form objects or fill imperfections. Follow manufacturer instructions exactly when mixing.

Below are problems that result from common mixing errors and methods for remedying them.

Sticky or Tacky Epoxy

Cured epoxy can be sticky to the touch either in places or across an entire piece. If environmental conditions are not ideal, epoxy can cure more slowly than anticipated. Consider placing the piece in direct sunlight or a warmer location to cure for an additional period of time, up to 24 hours.

If small areas of the piece are tacky, purchasing a resin spray will help fix the problem. Epoxy resin spray comes in an aerosol can and can quickly apply a glossy finish to your piece. Follow manufacturer’s instructions when applying.

If the entirety of the piece is tacky, consider sanding the entire surface of the piece with a medium-to-fine grit sandpaper. After the surface is abraded, pour a thin coat of properly mixed epoxy over the project following steps outlined above.

Failing to Cure

If you have waited the manufacturer recommended period only to find that your epoxy has not cured at all, the best solution is to start over. 

Cleaning supplies: 

• Gloves
• Rags
• Chisel
• Scraper
• Denatured alcohol
• Acetone 

Wear gloves to clean the epoxy resin. If the resin is still liquid, wipe as much as you can with a rag. Apply either denatured alcohol or acetone to the remainder. Allow epoxy resin to soften, then use the scraper or chisel to remove the remaining epoxy. After the resin is removed, sand your mold and begin the project again.

Scratched Epoxy Resin Countertops

Scratches will inevitably appear in your countertop overtime. To address these cracks is straightforward.

1. Sand across scratches with super fine grit sandpaper.
2. Thoroughly degrease and clean the countertop of dust.
3. Place mold around countertop.
4. Pour a very thin layer of freshly mixed epoxy to cover entire surface.
5. Wait for epoxy to cure, then demold.
6. Soften new countertop edges with a rag damp with acetone.

If you’re working with metal instead of wood, take a look at my metal epoxy reviews.

Conclusion

Epoxy resin can add a pop of color, protection, or can be used in many crafts. New advances hold promises for expanded use of epoxies. Many mistakes can be prevented by proper preparation. Addressing mistakes while resin is wet is possible. Mistakes in cured epoxy usually require pouring more layers.