G4 Pond Sealer (5kg)

G4 Pond Sealer for concrete and masonry ponds

G4 Pond Sealer is a standalone pond-sealing coating for suitable rendered concrete, brick and porous stone surfaces.

It forms a durable, non-porous coating directly over the prepared masonry surface without requiring a separate primer. It is designed to act as the finished pond-sealing system and must not be used beneath a fibreglass or GRP laminate.

The G4 Pond Sealer technical data states:
“Forms a non-porous seal on rendered concrete, brick or porous stone.”

Not suitable beneath fibreglass or GRP.
The current G4 Pond Sealer technical data states that this product is not compatible with fibreglass, PVC, butyl rubber, bitumen or waterproof render.

Where would I use G4 Pond Sealer?

• Sealing suitable rendered concrete ponds
• Applying a non-porous finish to suitable brick-built ponds
• Sealing suitable porous stone pond surfaces
• Refurbishing a prepared masonry pond without a fibreglass lining
• Creating a finished pond coating without a separate primer

Product description

G4 Pond Sealer is a single-pack, moisture-curing polyurethane coating designed specifically for sealing masonry ponds. It uses moisture within the air and substrate to cure and harden.

Once applied to a properly prepared porous surface, it forms a durable, deep-bonding and non-porous coating. It can be applied to a slightly damp substrate, but the surface must still be sufficiently dry and porous for the first coat to penetrate and obtain a strong mechanical grip.

G4 Pond Sealer can be applied at low temperatures and does not require a separate primer when used over a suitable prepared concrete or masonry pond surface.

Coverage and tin-size guide

The manufacturer's nominal consumption is approximately 550g per m² for the complete coating system.

Coverage is nominal and will vary according to the porosity, texture and condition of the pond surface. Rough or highly absorbent masonry may require more material.

Preparing and sealing a masonry pond

1. Check the pond construction. The pond must have a stable, sound masonry surface suitable for receiving a directly applied coating.
2. Prepare the cement render. The render must be clean, dry and porous. Highly polished or heavily trowelled surfaces are not advised because they may prevent the first coat from obtaining a mechanical grip.
3. Repair defects before coating. Fill and repair cracks, holes, loose areas and damaged sections before applying G4 Pond Sealer.
4. Remove contamination. The surface must be free from dirt, dust, oil, grease, loose material, paint, existing sealers and other treatments that could interfere with adhesion.
5. Ensure the surface remains porous. The product can tolerate a slightly damp substrate, but the masonry must still be sufficiently dry for the first coat to penetrate and obtain a mechanical grip.
6. Shake well before use. Ensure the product is thoroughly mixed before application.
7. Apply the first coat by brush. Work the coating evenly into the porous surface and avoid applying an excessively thick coat.
8. Apply the complete coating system. Use three coats of G4 Standard. Where a coloured finish is used, apply two coats of G4 Standard followed by two coats of G4 coloured.
9. Observe the recoat window. Recoat after approximately 60–90 minutes and do not allow more than four hours to pass between coats.

Do not fill the pond or return fish until the complete coating system has fully cured. The current January 2023 technical data does not state a fixed refill or fish-return period, so follow the latest written manufacturer guidance before returning the pond to service.

Features

• Designed specifically for sealing masonry ponds
• Forms a durable, non-porous coating
• Suitable for rendered concrete, brick and porous stone
• No separate primer required on a suitable prepared surface
• Three-coat standard application system
• Nominal consumption of approximately 550g per m²
• Single-pack, moisture-curing polyurethane
• Can be applied at temperatures down to 0°C
• Suitable for slightly damp but still porous substrates
• Not compatible with fibreglass or GRP