Pinhole/crack in Block repair?

they sell a plastic called stic tite for repairing aluminum radiators it is made by northern and sold by speedway motors part number 917 34230 I used it to repair a cracked block that was losing coolant cleaned the area with a wire wheel then heated it and cleaned again with muratic acid and wire wheeled again then heat again and touch the plastic material to the area and it just sucks right into the hole/crack and your good to go