Fiberglass (Polyester) Resin – Instructions for Use
Uses
Use fiberglass polyester resin with fiberglass fabric to make original parts in a mold, or use it with mat or cloth over fiberglass, metal, wood or concrete.
1. Surface preparation
- Clean and degrease/dewax the surface with acetone.
- Do not apply over epoxy, paint, varnish or Styrofoam. Be sure to test other surfaces first.
2. Mixing
Add MEKP hardener to only the volume of resin you can use within 10 to 15 minutes.
| Working temperature | MEKP hardener (by volume of resin) |
|---|---|
| Above 25 °C / 80 °F | ¾ to 1% |
| Below 15 °C / 60 °F | 1 to 2% |
- Working time: 15 to 20 minutes.
- Sandable: in 3 to 4 hours (can be longer in temperatures below 15 °C).
- Heat warning: unused catalyzed resin may start to get hot within 20 to 30 minutes. Keep the container on a heat-resistant surface.
- Temperature: do not use below 8 °C.
3. Choosing unwaxed or waxed resin
- Unwaxed resin is for applying multiple layers of fiberglass. Gelcoat or more resin can be applied over cured unwaxed resin without sanding.
- Waxed resin (add 5% Styrene Wax / Air Dry to unwaxed resin) is for final coats that need to be sanded. To apply more resin or gelcoat over waxed resin, remove the wax with acetone, sand, then wipe down with acetone again.
4. Making fillers
- Light filler or fairing compound: add 3M Bubbles, Micro Balloons or Talc to the resin.
- Structural filler: add Arkthix, Milled Glass Fibre or Short Strand Fibre, with 25% Colloidal Silica.
5. Clean-up
Clean brushes and tools with acetone. Read the product Safety Data Sheet (SDS) before use.