Description
A sealant applied straight into a hairline crack fails, and it usually fails within a season. There is no width for the sealant to bond across and no clean substrate for it to bond to — just dust and loose edges. Routing the crack out first is what turns a repair into a repair that lasts.
The V-profile does the shaping
A crack chaser carries a V-shaped rim rather than a flat one, so a single pass follows the crack and leaves a tapered channel behind it. That taper is what the sealant needs: a wider mouth to bond into, clean sound concrete on both faces, and a reservoir deep enough that the sealant can flex as the slab moves through its thermal cycle instead of tearing away from the edge.
Sizes and where it gets used
Three sizes, 4″, 4.5″ and 5″, mounting on a standard angle grinder. Dry rated, medium bond, formulated for both concrete and asphalt — parking structure decks, warehouse floors before a coating goes down, slab-on-grade repairs, and pavement crack sealing ahead of an overlay.
Follow the crack rather than trying to straighten it, take one steady pass, then blow or vacuum the channel out completely before the sealant goes in. Any dust left in the groove becomes the bond line and the repair fails there. Related: the Tuck Point Blade for mortar joints.
