G4 Pond Sealer – Clear or Black
Moisture-curing polyurethane sealer for concrete, blockwork & masonry ponds
G4 Pond Sealer is a single-component, moisture-curing polyurethane coating designed to seal, waterproof, and stabilise porous pond surfaces such as concrete, render, blockwork, and masonry.
Once cured, it forms a tough, water-resistant, fish-safe barrier, making it suitable for pond construction, refurbishment, and repair work.
Commonly used in koi pond builds and renovations, G4 is chosen where liners are not being installed and a rigid, sealed surface is required.
Manufactured by Bonda, G4 is a long-established professional product — not a decorative paint. A construction-grade pond sealer for rigid pond builds.
When in doubt, buy slightly more — running out mid-application risks poor results.
✔ Professional Pond Sealer | ✔ Multiple Sizes | ✔ UK Stock
Select your colour and size and seal your pond properly.
G4 Pond Sealer
✔ UK Stockist
✔ Trusted Pond & Koi Specialist
✔ Secure Checkout •
Easy Returns📦
UK mainland delivery🚚
Dispatch in 1–2 working days 💷
Free delivery on orders over £200