Essential Tools for a Professional-Grade Lining

Quality application tools and the right resin kit make all the difference. Choose brushes or rollers that minimise shedding, and pre-cut your fibreglass matting to suit awkward shapes before you begin. Investing in protective gloves and dust masks keeps every project both safe and comfortable.

Step 1: Prepare the Motorcycle Bag Surface

Begin by removing any internal fittings or liners from the motorcycle bag. Thoroughly clean the inside using a mild detergent and water, ensuring all debris, grease, or old adhesive residues are eliminated. Once dry, sand the entire interior using medium-grit sandpaper to promote strong adhesion of the fibreglass resin. Special attention should be paid to corners and seams, as these are most prone to moisture ingress. Wipe away all dust particles with a clean cloth to leave a dry, residue-free surface, which is essential for a smooth, lasting result.

If the bag has deep scratches or holes, these should be repaired before you start the lining process. In such cases, CROP 2K Fiberglass Putty – 750 ml + Hardener can be applied to fill and level the damaged areas. Allow the putty to cure fully and sand the surface gently for a flush finish before moving on.

Step 3: Apply the Fibreglass Resin and Matting

The lining process begins by mixing your chosen resin according to its manufacturer’s instructions. Carefully measure and combine the resin and hardener, ensuring a thorough mix to achieve proper curing. Ensure the surface is clean and dry immediately before application. Start by spreading a thin layer of mixed resin directly onto the bag’s interior with a brush or roller.

Lay the fibreglass matting over the wet resin, then saturate the mat with additional resin until it becomes fully transparent and adheres firmly to the surface. For reliable results, the Resin Fibreglass Repair Kit – Complete Polyester Resin and Hardener Set offers pre-measured components, including fibreglass cloth and instructions, making this step straightforward for beginners and professionals alike.

Repeat this process for all internal surfaces, overlapping sections of matting slightly for continuous coverage and added strength. Work methodically to avoid air bubbles, gently pressing out any that arise.

Tips, Common Mistakes, and Troubleshooting

Work in a well-ventilated space and never rush the mixing or curing stages—undermixed resin or premature handling can compromise both bond strength and waterproofing. Use multiple thin layers rather than a single thick one if you are new to working with resin. This reduces the risk of drips, bubbles, or uneven curing.

Check the interior regularly for uncured patches or missed areas—these can be patched promptly by mixing and applying a small fresh batch of resin. If you spot an air bubble after curing, sand the surface lightly and add a thin top-up coating for a seamless result. Always follow the kit or product safety instructions, and never skip personal protective equipment.

See the Results of a Proper Resin Lining

Well-lined motorcycle bags maintain their integrity even in harsh weather. After resin curing, you’ll notice a solid, seamless interior with no sharp matting edges, improved water resistance, and a lustrous finish. This robust lining not only protects your gear but also increases your motorbike’s load reliability over time.