Sticky zips. Ever since the original brass design was replaced by a range of other materials, zip fasteners have started to snag and jam.
Today’s invention is an aftermarket fix for all those low-precision plastic zips out there.
A semicircular tab (pale yellow) is attached to the normal zip handle (grey). This goes through the hole in the handle and is secured to a small, replaceable wax crayon (yellow) in a housing.
From time to time, the zip handle can be flipped forward, as shown, and the crayon allowed to contact both sets of teeth as the zip is closed.
Such an arrangement leaves a thin film of clear wax on the zipper and stops the usual swearing/tugging/jamming when the rain comes on suddenly.