What You’ll Need

• Resin Fibreglass Repair Kit – Complete Polyester Resin and Hardener Set – For structural crack repair and reinforcement.
• CROP 2K Fiberglass Putty – 750 ml + Hardener – For filling and levelling holes, dents, or deeper damage.
• “FixExpress” – Two-Component Epoxy Glue 500g – For quick repairs or small adhesive fixes.
• Strong Technical Degreaser for Resin Projects – 100% Natural Formula – To thoroughly clean the area before any repair.
• Sandpaper (various grits), masking tape, sponge, protective gloves and eye protection, paintbrush (for resin application), clean cloths.

Essential Preparation for Lasting Results

Proper cleaning and degreasing are the foundation of a strong repair. Even invisible residues can prevent adhesives and fillers from bonding securely. Take extra care with surface prep—using products like Strong Technical Degreaser for Resin Projects – 100% Natural Formula—to give your repair materials the best possible grip and durability.

Step 1: Thoroughly Clean and Prepare the Damaged Area

Start by draining and drying the bathtub completely. Any lingering moisture, soap scum, or oils can interfere with new material adhering to the resin surface. Use a mild detergent and warm water to remove everyday residue, then rinse thoroughly.

After basic cleaning, deploy a powerful surface degreaser to eliminate grease, silicone and any remaining contaminants that are hard to clean with standard products. For this, Strong Technical Degreaser for Resin Projects – 100% Natural Formula offers effective removal without damaging the tub’s surface or harming your skin. Dry the area with a fresh cloth and allow it to air for a few minutes before moving to the next stage.

Step 2: Sand, Remove Loose Material and Mask Off Surroundings

Lightly sand the damaged section with fine-grit sandpaper to roughen the surface. Remove any loose resin or flaking edges to create a solid base. This step helps new materials achieve a strong bond. Take care not to enlarge shallow cracks unnecessarily, but ensure the repair region is clean and free of dust.

Mask off the undamaged area surrounding your repair with masking tape. This will prevent overspill and make blending or finishing easier later.

Step 3: Fill Cracks, Chips, or Holes for Structural Repair

Choose a repair material that matches the depth and size of the damage. For small cracks or chips, you can use a two-component epoxy adhesive such as “FixExpress” – Two-Component Epoxy Glue 500g. Mix the components as instructed and carefully fill the damage, ensuring full coverage but not overfilling. Allow it to set according to product guidelines before further handling.

For deeper cavities, dents or larger holes, a fibreglass-reinforced putty like CROP 2K Fiberglass Putty – 750 ml + Hardener provides added strength. Apply the mixed putty in thin layers and build up until flush with the surrounding area. Smooth with a spatula or application tool after each layer.

Step 4: Apply Structural Reinforcement if Needed

If the bathtub has suffered significant cracking or stress zones, reinforce with a fibreglass mat and polyester resin system. Follow the kit instructions supplied with the Resin Fibreglass Repair Kit – Complete Polyester Resin and Hardener Set for safe mixing and application. Cut a suitable section of the fibreglass mat, apply the mixed resin, and position the patch firmly over the cleaned damage. Use a brush to saturate the mat and eliminate air bubbles, ensuring full integration with the tub’s surface. Allow each resin layer to cure completely before moving on.

Step 5: Sand Smooth and Finish for a Seamless Look

Once all repair layers are fully cured, carefully sand the repaired area, starting with medium grit and progressing to fine grit for a smooth, flush finish. Check periodically with your fingertips for flatness and uniformity. Remove masking tape once no sanding remains.

If painting or resealing is required to match the rest of the bathtub, ensure the repair is dust-free before applying any topcoat. Follow the paint or sealant manufacturer’s instructions for curing time before exposing to water again.

Tips and Common Mistakes to Avoid

Thorough preparation is essential for a reliable repair—skipping cleaning, degreasing, or sanding may lead to poor adhesion, peeling, or return of leaks.

Always use the recommended repair material for the damage size: smaller cracks do not require structural fibreglass, while large holes cannot be securely patched with adhesive alone. Let each layer cure fully before touching or sanding, as premature finishing will weaken the final result.

Test your repair with water before returning the bath to regular use—fill incrementally, check for drips, and ensure no movement or flexing at the repair site. Patience here guarantees success and saves repeat work later.

Achieving a Professional Finish on Resin Bathtubs

Successful resin bathtub repairs blend seamlessly with the original surface and retain waterproof integrity. After thorough sanding, ensure the repaired area is dust-free before sealing or painting. Assess the overall result visually and by touch, aiming for an even surface that resists moisture and daily wear alike.