There's no polite way to describe this... but it'll certainly keep your sealant from curing in the tube!

Next time you work with a sealant, be sure to leave it hanging, and don’t be tempted to remove the erm… snotty bit that dangles from the bottom.

When we asked Laurie Brebner of Marine & Industrial to give us a hand plugging vent leaks on Project Boat Maximus, he got to work with some Sikaflex 291, which was ideal, being a great sealant with only mild adhesive properties (you don’t want it to stick too hard or you might never get the fitting off in the future).

After removing the deck vent, he generously packed the sealant around the deck and in the screw holes. “You can’t use too much,” he said. “All it will do is just squeeze out, it’s not there to be pretty.”

When Laurie had finished with the sealant he hung the sealant gun on the mast.

“Sikaflex has a shelf life of around 6 to 8 months but cures in the nozzle,” he said. “One trick to do with any sealant, particularly polyurethanes, is to leave the gun hanging. In not too colloquial terms, we call this bit the ‘snotter’. They cure from the tip backwards, so leave the snotter on to stop it from going off.”

Laurie also suggested using masking tape around the end of the nozzle. This slows down the curing process by starving it of any air. “Remember, most sealants cure by absorbing moisture from the atmosphere,” he added.

Do you have any tips and tricks for PBO readers? If so, email them to

The hard sell…

Do you know any young boaters or people who dream of owning a boat one day? A recommendation from you to start reading PBO could save them money in the long run and means our experts can continue helping all boat owners with their problems.

Subscribe, or make a gift for someone else, and you’ll always save at least 30% compared to newsstand prices.

See the latest PBO subscription deals on