Polishing & Paint Correction2 min read

Paint Runs and Sags: Set the Boundary Between Detailing and Refinishing

Runs and sags are film-shape defects, not ordinary wash swirls. A workshop should establish the repair boundary before adding them to a paint-correction package.

Updated · NANOLAB Knowledge

Why a run changes the task

A run is a local accumulation of paint. Improving its surrounding reflection with polish does not level the accumulation predictably. The panel may also have an unknown repair history or incomplete readiness for abrasive work. Record the defect with a side-lit photograph and ask the bodyshop what paint system and finishing process apply.

Do not begin with a blade or a sanding recipe

Levelling a run can involve specialised skills and a controlled abrasion process. A universal grit progression or a fixed number of passes is not a responsible answer for an unidentified panel. Edges of the defect and the surrounding film may not tolerate the same work.

Use a separate authorisation scope

Distinguish cosmetic enhancement of the sound surface from repair of the run. State whether your workshop has the information, equipment and competence for the latter. If it does not, refer that operation and continue only with the agreed unaffected areas. A customer requesting a perfect finish does not supply the missing paint-system information.

Inspect after the repair, before protection

Once the refinisher has completed and released the work, check the texture transition, residual sanding marks and clarity under more than one light. Choose any additional polish from a controlled test. Delay protection until the paint and coating instructions permit it, and keep the repaired area identifiable in the service record.

Frequently asked question

Will heavy cut compound level a paint run safely?

Do not treat compound as a substitute for an assessed run-removal process. Establish the film condition and the appropriate repair method first.