Very good to make minor repairs holes and cracks, when used according to instructions, so moisten with the defect site and so on. You should protect your hands is dried to get very bad from the skin. Very long and good curing is extremely important before you step back boldly into the gas pedal, otherwise the Rep is short-lived. When well cured, it is as hard as concrete. For larger holes a verstrebendes material would be applied before, I have ever wrapped chicken wire for a job and then smeared with the paste, years has held. Highly recommended, also for sealing new exhaust parts that are a bit too large in diameter.