When installing a patch, how much should a panel be ground around the edges?

When installing a patch in dry van repair, the correct amount to grind around the edges of the panel is 20mm. This measurement is critical to ensure proper adhesion between the patch and the surrounding material. Grinding this amount creates a well-prepared surface that helps to eliminate any contaminants and irregularities, allowing for the new material to bond effectively. Additionally, grinding to this depth can also help to alleviate stress concentrations around the repair area, reducing the likelihood of future failure.

The choice of 20mm is based on industry standards and best practices, which take into account the necessary surface area for a secure attachment, while still being manageable for the repair technician. Other options may not provide adequate surface preparation, which could compromise the integrity of the repair.