If you’ve worked with epoxy resin before, you’ve probably noticed that the result does not always have a crystal clear surface, but rather a matte finish. Luckily, there is a very simple procedure to give your resin project a beautiful gloss: epoxy resin polishing. Learn more about how to polish epoxy resin after sanding below.
Sanding and polishing epoxy resin are two very important steps that can make or break a project. While sanding resin removes any excess product and smoothens the surface of your DIY project, polishing can help you obtain that perfect, shiny finish. Objects such as resin art and jewellery, tables, floors, and other wooden objects are suitable for subsequent polishing after curing.
Sanding epoxy resin
Sanding epoxy resin is basically preparing the resin for polishing. Sanding reduces dust formation and is, therefore, safer for your health. To get the perfect surface for your epoxy resin work piece, sanding after curing is essential. So let’s see what we need to sand epoxy resin and how to do it properly.
What you need:
Suitable for larger areas, we recommend wet sanding for effective blush removal. Wet sanding is normally done by hand. Wet sanding removes amine blush while you sand, reduces clogging of the sandpaper, and reduces dust and exposure to partially cured epoxy. Curing can take up to 24-48 hours.
Step by step instructions:
Use soap and warm water to clean your resin project.
Wet sand the resin with 400 grit sandpaper to remove any scratches.
Sand it again with 600 grit sandpaper, then with 800 grit sandpaper, 1000 grit sandpaper, and finally with 1500 grit sandpaper.
Dry off the resin piece and apply the polishing compound across the surface as instructed below.
Polishing epoxy resin - step by step
Thorough polishing is the cornerstone for a perfect surface. Polishing resin is a pretty straightforward process that just involves cleaning, sanding, and applying a polishing compound to your resin piece.
What to use to polish resin:
- Polishing compound for epoxy resin
- Microfiber cloth or towel
- Buffing wheel or polishing tool
- Power drill
*If you want to polish shapes or small objects, it is sufficient enough to equip a standard drill with a special polishing attachment.
Step by step instructions:
- After sanding, apply the polishing compound across the entire surface of the resin.
- Rub the compound into a small piece of resin using a microfiber cloth. Move the cloth in circular motions and apply extra pressure to areas that have visible scratches.
- Use a buffing wheel (or any polishing tool) to polish a larger piece of resin. It is best to attach the buffing wheel to a power drill so that the process is easier. Apply it as evenly as possible until the resin is shiny and smooth.
- Rub the surface with a microfiber cloth to get a glossy finish.
How to polish resin with a Dremel
If you are working on a smaller piece (such as charms), using a Dremel tool will do just the trick. Go over the entire piece as necessary and avoid using too much pressure.
Be sure to keep the piece moving and not buff any one area for more than a couple of seconds. Wash with soap and water to remove any polishing compound residue. You can always finish the process by hand. The basics are the same. If you want to work on edges or straight surfaces, you can simply wrap the wooden block with a cloth.
What if something goes wrong?
Mistakes can happen even to the best crafters. However, it is important to know how to prevent and fix common issues that can arise.
How to fix cloudy epoxy
There are a number of factors that can lead to a cloudy epoxy: humidity, texture of the mold, and temperature of the resin. To avoid cloudy epoxy, make sure you do not work in humid conditions and that the mold is clean and completely dry before pouring. The resin must also be the correct temperature for the correct finish - 122°F (50°C). If it’s too cold, it can affect the finish. To warm up the resin, place the bottles of pre-mixed resin in warm water and let the resin warm up before mixing. Lastly, keep in mind that if the surface of your mold is shiny, the resin will be shiny.
If your resin is still cloudy after taking these precautions, you can mix a small amount of the resin you used to cast your project. Use a paintbrush and paint a light layer over the top of your project. This will add that shine back. Then let it dry again for 24-48 hours in a covered box.
Prevent and cure bubbles
Warming up the bottles of epoxy prior to using is key to preventing bubbles. When mixing the resin and hardener, mix slowly, making sure to scrape the sides and bottoms of the mixing container. If epoxy is stirred fast, it creates more bubbles. When pouring your epoxy into a mold, pour very slowly and from one side of the mixing cup into one side of the mold. If bubbles are present in a cured piece, use a razor blade to pop the bubbles and create an open cavity. Mix a small amount of epoxy to fill in those holes; let cure for 5 hours then re-flood the surface.
Epoxy turned white
Epoxy can turn white due to high humidity or when the coating was not completely dry at the time of application. Assuming that the coating has fully cured, the only way to fix the problem is to sand it thoroughly and apply another coat on top.
Don’t settle for dull epoxy projects! Let your workpiece shine through! And don’t forget that, when using a polishing compound, working in small sections will ensure an even shine for your project.