Stop a hairline crack in a basin, sinks and leaking plug surrounds before it turns into a bigger leak
“Tried many sealants for a tiny crack in my composite kitchen sink without success. Then tried Capt Tolley’s seal and alas great success.”
– M.F. Kasim, Judge.me review
Basins and sinks can develop hairline cracks from an impact or a stuck fitting being forced loose, leading to slow leaks that are easy to miss until water starts appearing underneath.
Captain Tolley’s Creeping Crack Cure uses capillary action to seep into these cracks and seal them from the inside, without needing to replace the basin or sink.
“My wife dropped a mixing bowl into our new composite kitchen sink causing a hairline crack through which water leaked badly. I found reference to Captain Tolley on a help site on the web & very glad I did. I put on two applications just to be sure and the leak is fixed. Very easy to use, virtually invisible and has saved me £400 for a new sink. Fantastic!!”
– Alan Strudwick, Judge.me review
“Just installed a granite sink and it had a microscopic crack, and I didn’t want to uninstall the worktops. Used it several times and it was a complete success. No more water disappearing. I did test it on a sample first to be sure it left no visible marks. Highly recommended.”
– Mark Johnson, Judge.me review
One customer’s basin developed a hairline crack after force was used to remove stuck old taps – the sealant ran straight through the first couple of applications just as water had, but by the third and fourth only a drop escaped, and it’s now completely watertight.
– Nick, verified Amazon customer
*For best results, apply in dry conditions above 10°C / 50°F and keep the area dry while it cures. Cold or damp weather slows curing, and moisture can dilute the sealant before it sets, so allow extra time if conditions aren’t ideal.
This is completely normal, not a sign it isn’t working. The crack takes several applications to build up enough sealant to hold – most customers find it stops running through by the third or fourth application, or you can apply some tape underneath the crack, and any sealant left to dry on the surface actually forms a strong bond with the porcelain as it cures.
It’s most reliably reported on porcelain basins. On plastic or resin sinks – especially ones that flex under normal use, like a lightweight camper or caravan sink – the constant movement can reopen the crack even after it initially seems sealed. If a plastic sink keeps recracking in the same spot, that flexing is likely the underlying cause rather than the repair itself.
No, not once it’s cured – just give it the full 48 hours before running the tap or using the sink again, since water contact too soon can wash the sealant out before it sets.
Hairline cracks in window frames and glazing let moisture in, especially where the seal around the glass has shrunk or perished with age.
Cracked plates, bowls, and treasured china can be repaired before the crack spreads further with every wash and use.
Constant exposure to water and weight makes shower trays and door seals especially prone to hairline cracks that lead to leaks in the floor below.
Conservatory glazing seals face the same extremes of sun and rain as a boat's coachroof, making them prone to cracking and water ingress over time.
