When preparing a pinchweld with more than 24 square inches of rust, what is the recommended preparation method?

The recommended preparation method for a pinchweld with more than 24 square inches of rust is to use Glass Cleaner and scuffing. This approach is effective because Glass Cleaner helps remove contaminants that could interfere with the adhesion of the new materials. Simultaneously, scuffing the affected area provides a rough texture, which enhances the bonding surface for adhesives and sealants.

In cases where rust is present, it is crucial to ensure that any debris or loose material is adequately cleaned away, and the surface is prepped to promote effective adhesion. This dual approach of cleaning and scuffing ensures that the pinchweld is not only clean but also properly prepared to handle the stress of installation.

Other options do not provide a comprehensive solution: applying Metal Prep alone may not address all contaminants, while using Glass Cleaner or SP-207 by themselves does not adequately prepare the surface for optimal adhesion in the presence of rust.