Concrete cracks are like potato chips—it’s very hard to stop at just one. If you’re lucky enough to catch a crack before it has spread, you can start with Concrete Welder in Cartridges. With its fine-point mixing tip it is easy to repair small cracks. If the concrete cracks are wide, you can put a little sand into the cracks before injecting Concrete Welder. Use a straight edge or ruler to smooth the surface for a flush finish. Concrete Welder comes in a two-chambered unit that can be used with any hand-operated dual cartridge gun.