Pool Lining with Polyester Resin [DIY Guide]

Building or renovating your own swimming pool? Using polyester resin and fibreglass gives your pool a super-strong, waterproof finish that lasts for years. In this article, we explain step by step how to line a pool with polyester. We also show which materials you need and provide practical tips from experience.

What you'll need

To finish a pool with polyester, you will need the following materials:

• RESION G4 Polyester primer (primer for concrete)
• RESION Polyester laminating resin
• MEKP-hardener
• Fibreglass chopped strand mat 450 gr/m²
• Polyester gelcoat (pre-coat)
• Polyester swimming pool topcoat (NPG)
• Auxiliary materials such as  brushes, rollers, gloves and mixing cups

Step 1. Prepare the pool structure

• Pour a reinforced concrete floor with a minimum thickness of 15 cm. Ensure the floor is completely level.
• Build the walls on top of this floor.
• Install all necessary fittings, such as:
  • Skimmers
  • Inlets
  • Floor drain
  • Lighting (optional)
• Round off all corners with sand-cement. This prevents stress concentrations and improves the adhesion of the coating.

• Allow everything to cure completely. The substrate must be dry, stable, and free of grease before you start.

Step 2. Apply the primer 

• For proper adhesion to concrete, use G4 Polyester primer.
• Apply the primer evenly over all concrete and masonry surfaces.
• Allow the primer to become tack-free (do not fully cure or sand). Depending on the temperature, this takes between 30 minutes and four hours.
• Continue laminating within 24 hours.

Step 3. Laminate with fibreglass and polyester resin

• In this step, you will laminate the concrete with fibreglass mats (CMS) and polyester laminating resin.
• Mix the polyester resin with approximately 2% MEKP hardener.
• Apply the first layer of resin to the primed surface.
• Lay the fibreglass mat 450 g/m² into the wet resin.
• Fully saturate the mat with extra resin and work wet-on-wet using a brush or roller.
• Use a de-airing (paddle) roller to remove air bubbles from the laminate.
• Apply a second layer of fibreglass mat and resin in the same way.
• Allow the laminate to cure for approximately 4-6 hours.

Step 4. Apply gelcoat

• For a smooth, even base layer, first apply a gelcoat. Gelcoat is available in any RAL colour at Polyestershoppen.
• Mix the polyester gelcoat with approximately 2% MEKP hardener.
• Apply the gelcoat with a brush or roller, using around 350–450 g/m². Avoid brush marks.
• Allow the gelcoat to cure for 2–3 hours before continuing. Note that gelcoat will always remain slightly tacky.

Step 5. Apply the pool topcoat

• The topcoat is the protective layer that comes into contact with pool water. RESION Topcoat is available in any colour and is resistant to chlorine and UV.
• Mix the polyester topcoat with approximately 2% MEKP hardener.
• Apply the topcoat with a brush or roller, using around 300–400 g/m².
• Allow the topcoat to cure for at least 48 hours before filling the pool with water.

Renovating an existing pool with polyester

This is also possible! Follow these modified steps:

• Sand the surface with P60 grit.
• Degrease thoroughly.
• Apply a new layer of pool topcoat immediately.
• Optional: repair damage with fibreglass mat and polyester laminating resin.

Questions about your project or products?

Feel free to contact our specialists. We are happy to advise you via email or WhatsApp on creating your dream pool!