Ensure that the area to be repaired, is clean and free from loose rust. Dampen repair area with water and apply with a knife, forcing into whole crack to give strength. If necessary, soften putty with water. After use, replace lid firmly onto container. Once putty has been applied, start the engine and allow idling for a few minutes in order to accelerate the hardening process and to improve adhesion. When completely set, the exhaust system is ready for normal use.