Should I Roughen Resin Surfaces Before Applying Glue?

Why Surface Preparation Matters

Expanded resin surfaces tend to be smooth and sometimes glossy, which can make it difficult for adhesives to grip firmly. Light sanding or roughening the area improves the ability of epoxy glues to form a mechanical bond, reducing the risk of the join failing over time.

Taking a few moments to prepare the surface pays dividends when it comes to the durability and strength of your finished project.

How to Sand or Roughen Resin for Bonding

• Use a fine to medium grit sandpaper (e.g., 120–240 grit) to gently scuff the surface where adhesion is needed.
• Work evenly—avoid gouging or excessive pressure that could damage the part.
• After sanding, wipe the area with a dry cloth to remove loose dust for a cleaner, more reliable bond.

This approach can be used on a variety of expanded resin items before using epoxy adhesives such as the FixExpress Two-Component Epoxy Glue.

When This Matters Most

Thorough surface preparation is especially important if you’re seeking a high-strength, long-lasting bond for repairs, structural joins, or external applications subject to moisture or stress. Neglecting this step can lead to weaker adhesion for most types of epoxy or multipurpose glue.