Rusting Nailheads

May 08, 2017
This is identified by reddish-brown stains and spots on the paint surface.

POSSIBLE CAUSES

  • The rusting of non-galvanised iron nails, causing bleed-through to the topcoat.
  • Non-galvanised iron nails that have not been countersunk and filled over.
  • Galvanised nailheads beginning to rust after sanding or excessive weathering.

SOLUTION

When painting a new exterior construction where non-galvanised nails have been used, it is advisable to first countersink the nailheads, then seal them with a top-quality, water-based all-acrylic or siliconised acrylic sealant. Each nailhead area should be spot primed, then painted with a quality water-based coating. 

When repainting exteriors where nailhead rusting has already occurred, wash off the rust stains, sand the nailheads, then follow the same surface preparation procedures outlined above.