Preparing Your Workspace and Tools

Set up your work area with good ventilation and a stable, dust-free surface. Gather all materials in advance and read safety guidance for each resin. Remove distractions before beginning; accurate timing and attention are key when working with resin on wooden spearguns.

Step 1: Prepare the Wooden Surface

Begin by ensuring your speargun is fully dry and free from any previous oil, wax, or other coatings. Saltwater can linger in wood pores and lead to future failures if not entirely removed. Lightly sand the entire surface, focussing on rounded edges and any intricate carvings. Wipe away all sanding dust with a clean, lint-free cloth and follow up with acetone or a similar degreaser to eliminate residual oils or contaminants.

Ensure the speargun is completely dry before coating, as moisture can become trapped and weaken resin adhesion. Mask off trigger mechanisms or any metal parts not intended for resin coverage.

Step 3: Build Up Protective Resin Layers

Once the initial penetrating coat has cured, sand lightly with fine-grit paper to ensure future layers adhere properly. Proceed to apply two or three further coats of clear epoxy resin, allowing each layer to cure as directed. These coats provide surface resilience, improve UV protection, and give a clean, professional finish suitable for underwater conditions.

A clear epoxy such as “Trasparente” – Multipurpose Clear Epoxy Resin for Casting – Up to 2cm works well for visible surfaces, or use “Icrystal” – Clear Epoxy Resin – Odourless Formula – Up to 1.5cm for an odour-free workspace. Apply each coat thinly and evenly with a clean brush or spreader.

Apply resin in thin, controlled layers and allow proper curing time between coats. Sand lightly between coats for optimal adhesion and smooth finish.

Step 5: Final Inspection and Finishing Touches

After all resin applications have cured completely, inspect the speargun for any missed spots, drips, or areas needing touch-ups. Sand lightly again and polish if desired for a smoother grip along the handle and barrel. Remove masking tape, clean exposed parts, and ensure all moving components are free of resin build-up before reassembling.

Inspect thoroughly for gaps or missed spots, as even minor uncoated areas can allow water ingress over time. Always test waterproofing in shallow water before use in demanding underwater settings.

Getting the Best Waterproof Finish

Allow each coat to cure fully before light sanding and reapplication. Use a mineral wax or similar release agent to protect critical areas from accidental resin overflow. Testing in a controlled environment first helps identify any preparation gaps or weak points, ensuring the speargun remains watertight underwater.