Install injection ports: Surface Ports (short rigid-plastic tubes with a even base) serve as helpful entryways for getting the repair material into the crack. They remove the requirement to drill into the concrete, reducing labor time and cleanup. The base of the port is placed directly over the crack and bonded to the surface with an epoxy paste. A general rule-of-thumb is to space the ports an inch apart for each inch of wall thickness.
Seal the surface: Use an epoxy adhesive (such as Emecole 301) to seal on top of the exterior ports and exposed cracks. The paste cures in about 20 to 45 minutes to provide a surface seal with excellent bond characteristics that holds up under injection pressures. The total exposed crack is enclosed with the paste, leaving only the port holes uncovered.
Inject the crack: Start injecting at the lowest port on the wall and continue until the epoxy or urethane begins to ooze out of the port above it. That's the visual sign that the crack has been packed to that level. Cap the first port with the cap provided and go up to the next port, repeating this process until the entire crack has been packed with epoxy or urethane. Allow the compression spring on the dispensing tool push the material into the crack using slow, constant pressure. This will diminish the possibility of leaks or blow-outs and permit time for the repair material to completely infiltrate the crack.
Remove the ports: Allow 24 to 48 hours at room temperature for the epoxy or polyurethane to cure and pierce into the cracks. The injection ports can then be detached by striking them with a trowel or hammer. If appearance is an issue, the epoxy surface seal can be chipped away or ground off with a sanding disk. An additional alternative is to employ a surface seal that can merely be peeled off the wall after the repair is completely cured. Emecole manufactures a polyurea-based seal that develops a durable sufficient bond to allow the injector to accomplish the work, but is flexible and can be peeled away when the job is done.