Gold LabelUnderwater Sealant, 290 ml, Black

Fabulous to work with, although my job was challenging to say the least, resealing pond to perimeter slabs, difficult with water in the pond although I dropped the level. Not tested it yet but if it still loses a bit of water over the too it won't be a fault of this product. Speedy delivery, fair price. Thank you. Judy, Bristol

I have ordered several of these, over the years, I like to keep one in, as I have a pond with a butyl liner, this stuff is brilliant, says what it does on the tube. It's got me out of a scrape, when rats have chewed my liner a few times. Speedy and safe in the water with fish. Easy to use ,but I would recommend gloves as it sticks really well.

I have purchased both the clear and the black. For some reason the clear seems not to be so good to use for wet places or under water. The black I found to be much better. Strange! I have used them to seal edges around the pond and as an adhesive in the pond. Does a decent job. Wouldn't get the clear again though.

Having managed to slice a 2cm hole on a crease in my outdoor pond liner I was unsure how to repair this, a patch was not possible. I did drop the pond level to access the damage so can't comment on underwater use. I inserted the nossel through the liner to hopefully block the hole from behind and also added more on the surface. It might not look pretty but you can't see the repair when the pond is full. The repair seems to be completely watertight so job done. Obviously can't speak for longevity time will tell. It's an excellent product but I found it difficult to get out of the tube, warming it up in hot water helped. Take care it sticks to everything!

Worked well on the pond but just used it to reseal motorhome windows. The rain was lashing down and the ordinary stuff wouldn't have worked. This did. You might think it's expensive for mastic but for the right job it's well worth it.

This product is amazing and I wish I discovered it sooner.My pond has always had a slow leak since I bought the property and it was already there and it was annoying, but I lived with it.However recently I was working by the side of the pond and dropped a saw which tore big jagged holes in the liner.... I was mortified and the level dropped by half within hours.After lots of research and not much luck and almost resided to the fact I was going to have a mammoth task ahead redoing the pond, I discovered this product.Skeptical but I tgought for the price, worth a shot.Amazing.Easy to apply, does exactly what it says on the tube and whilst I did it, I went around and covered a few tiny holes at top and pond is the fullest and best it's looked since I have moved in and staying full.For the large holes from the saw teeth, I bought a tiny pond liner from here, which was cheap and cut a small patch, like repairing a bike tyre and it's worked a treat.£20 spent in total and pond like new.

Disappointing results - does not stick if surfaces not completely dry. Drained pond for 2nd attempt and stuck patch carefully in accordance with instructions leaving good bead & not pressing flat. Patch stuck very well but minor leak through bead - stuck 2nd patch over top but still very minor leak.

I wanted to repair a pond liner by filling in the folds above and below waterline and round the level where the water settled with the leak. No option to let it drain down below the line as the leak level was so low in the first place.It adhered fine to the dry liner material, however it just drifted off underwater no matter how I tried to push it onto the liner. Would not stick even when I tried to force it on with my finger,Worth noting there were comments saying the same about the clear version - wonder if they changed for the mix?Shame, I thought it would solve a problem, nothing else seems to be out there.It did sound like it would - and nothing in any instructions to tell me to do anything differently.I bought 2 of these and have asked for a refund on the second. At nearly 20 quid each I think it reasonable to do so since it did not do as advertised.I would still say it was good on dry material.