How to Polish Polyester Resin

Polyester resins are commonly used to make knickknacks and decorations found around the home.

Polyester resin, sometimes referred to as polyresin, fiberglass resin or cultured marble, is an artificial material similar to natural resin. Resin is a hydrocarbon based secretion of plants and trees with valuable chemical and physical characteristics and many uses. Other than natural resins, there is a big market for various synthetic resins and polyresin is the most versatile and affordable one. Polyester resin is actually a highly viscous, hardened liquid and it’s used for casts, molding sheets, jewelry, decorative furniture and sculptures.

Things You'll Need

• Multipurpose cleaner
• Sponge
• Sandpaper
• Drill, optional
• Buff pad
• Lint-free cloths
• Polish gel
• Wax

Instructions

1. Prepare the polyester resin for polishing by removing any visible and loose dirt from its surface. Clean the surface with warm water and a multipurpose cleaner and use a mild sponge. Make sure there is no dirt or grease after you clean the polyester resin.

2. Treat the surface of the polyester resin with sandpaper. First use a semi-coarse grit sandpaper and then move to finer grit. Depending on the object you are polishing, you can start with 320 or 400 grit sandpaper. Then move to 600, 800 and, finally, 1,200 almost as a buffing treatment. While treating the surface with sandpaper, use either a straight or a circular motion, depending of the object and the final look you want to achieve. If you want, use a circular drill to treat the surface of polyester resin with sandpaper.

3. Buff the polyester resin with a buffing pad if necessary. You can use a drill with a buffing pad. If you are doing it by hand, use a soft buffing sponge. At this point, the surface of the polyester resin will be even and smooth.

4. To make the surface glossy, apply polish paste to the polyester resin and rub it in with a soft, lint-free cloth. Use circular motions and make sure not to miss a spot.

5. Apply a thin, light coat of wax to protect the newly polished surface of the polyester resin. Use a different dry, soft cloth to apply wax. Rub the surface until it is shiny and glossy.

Tips & Warnings

• You can choose a polish paste or gel that has a wax compound in its formula, thus combining Steps 4 and 5.

• Wear protective latex gloves when dealing with chemicals, even if they are relatively mild, like polish and wax.

References

• Action Hobby: Polyester Resin
• RV Basics: How to Restore Gelcoat