Corrosion caused by moisture creeping into the small gaps between spot welded panels is one of the most common problems encountered on older vehicles. Using our P130 Weld-thru Zinc Rich Primer prior to assembly will help combat this, but for assembled panels you can only hope to seal out moisture with a good quality seam sealer applied over the joint with a brush or spatula. Will not sag; touch dry in hours; Brushable Seam Sealer can be painted over in 2 to 3 hours.