What is an acceptable condition for a patch made to an exhaust pipe?

A patch made to an exhaust pipe using arc or acetylene welding is considered acceptable because these methods create a strong, permanent bond that can effectively restore structural integrity to the exhaust system. Welding provides a solid repair that can withstand the high temperatures and pressures typically present in exhaust systems.

In contrast, using duct tape or zip ties would not be appropriate for exhaust pipe repairs. Duct tape lacks the durability and heat resistance required for exhaust applications, making it ineffective in the long term. Zip ties, similarly, do not provide a strong enough hold or thermal resistance needed for this environment. Therefore, the proper method of welding ensures that the repair is reliable and safe, maintaining the functionality and safety of the exhaust system.