Polar Leak Fix Black Paint - 1 Litre - Instant Waterproof Roof Sealant - Ideal for Leaks, Cracks & Roof Repair - Concrete, Brick, Metal, Drainpipes & Gutters - Easy to Apply

We bought this to seal an old fibreglass water feature which had sprung a slow leak. It was tricky getting the sealer into all the nooks and crannies of the pump sump, but that's not a complaint against the sealer. Imagine 'painting' a the inside of your hallway through the letterbox. As I was unsure whether my arm was long enough to reach unseen into the distant recesses and achieve a good seal, after a couple of days, I treated the bottom exterior surface too.A separate test on a small stainless steel dish with small holes torn in it was far more easily assessed, it sealed well with a dab of sealer on both sides. This is now used as a bird water dish.Both treatments have been successful and remain waterproof after three days use.Coverage thoughts - Given the nature of the fibreglass water feature task, I was unsure whether I'd be pouring it in and swilling it around to achieve a quick and easy seal, however, on opening the 500mL tin, it became apparent the viscosity of the sealer made this impractical - it needed to be painted on. For this I used an old brush I didn't mind discarding, since cleaning would be fraught with messy issues and time consuming. In total, I have probably covered about 1.5 square metres area, which has used just over half the 500mL tin. That might not sound like much, but it adhered to the surface and covered well - I was trying to achieve a decent thick coat, going much further than I thought it would.Should the need arise, I would definitely buy again.

Nice and Clear, easy to apply but best to add several coats.

It works! After trying silicone etc to fix a few cracks in my water feature to no avail, I used this as a last resort before I was going to take it to the tip 🙁 but it worked perfectly. After painting it on it dried within an hour in the sun and doesn’t need a second coat although one of the cracks was quite big.

Leak Seal is a very good product when the conditions are perfect. You need good weather, a clean surface and time. The seal is very liquid and will run into small cracks. It will not stop a leak in process. The source of the leak has to be stopped first. The area dried before Leak Seal is applied. If you manage to do that then apply Leak Seal and it dries in time, as described on the tin. Then the Seal will be very good. Note it says only apply one generous coat. This is because further coats will effectively dissolve the first coat and take longer to set/dry. Applying heat also dissolves this product in my experience.

Really good I got this for a quick fix for my flat roof and 2 year late it’s still not leaking

This was applied to a felt roof which had had a small leak - being transparent, it doesn't seem too obvious but it does add a more reflective coat so does show under close inspection. Paint consistency is very thick, making it easy to slather on as per the instructions, while giving your brush hand a good workout! The surface remains sticky after drying so will tend to collect debris more. However (touch wood) it does seem to have worked so far in fixing the leak.The product safety warnings should be carefully observed. Even while wearing a facemask and outside, the fumes were noticeable. This is very much an outdoors product.

So far so good. I used this on a flat felt roof where the edge had started to crack. Easy to use and doesn’t look obvious because I chose the clear product.

Worked a treat for me on my gutters would use again