Is there a suitable adhesive / sealant to use on our PVC pond liner?

Any adhesive compatible with PVC should suffice for bonding or sealing a PVC pond liner, as long as you adhere to the manufacturer's instructions. Here are a few additional tips: Surface Preparation: For the best bond, ensure that both surfaces to be joined are clean, dry, and free of grease or other contaminants. Depending on the adhesive, you may also need to slightly roughen the surfaces with fine-grit sandpaper. Underwater Adhesives: If you're looking to repair the liner without draining the pond, opt for adhesives that specify they can cure underwater. These adhesives are usually designed to be non-toxic and safe for fish and plants once cured. Curing Time: Allow the adhesive to cure for the full time recommended by the manufacturer before refilling the pond or exposing the repaired area to stress. Safety: Always use adhesives in a well-ventilated area and keep them out of reach of children. Wear gloves to protect your skin and eyes. To ensure longevity and a leak-free bond, it's crucial to select an adhesive that's specifically designed for outdoor, waterproof applications, especially when dealing with a pond liner.