Zero-clearance inserts prevent splintering and chip-out only as long as they remain zero-clearance. After a few years of use and several different blades, the slot on my insert had become too wide to do the job right. Rather than make or buy a fresh insert, I found a way to get a few more clean cuts from my old one.
To give your insert new life, affix a strip of clear packing tape over the slot from the top of the insert. Now flip it over and drip epoxy into the slot. (To save epoxy, use only as much as is needed to patch the slot top face.) Once cured, sand flush, reinsert the insert in your saw, and raise the blade to cut a fresh slot.
