Q. When beveled wood siding is going to be painted, should the nails be set below the surface of the siding and filled, or driven flush with the surface of the siding?
A.Stephen Jordan responds: I prefer to see the siding nails driven flush with the surface of the siding. Nails set and filled are very unforgiving of any movement or shrinkage in the wall framing. This movement may cause "nail pops" — the exterior version of the infamous drywall nail pop. Hardboard siding should be fastened so the nail head is drawn "snug" against the siding.
On the other hand, finish nails used to fasten exterior trim (the brick molding around a door unit, for example should be set and filled. DAP’s linseed oil-base Painter’s Putty is my favorite, and it works well under an oil-based primer. I add "whiting" (a thickening powder available through paint suppliers) to this somewhat gooey putty to make it more workable. If a latex primer is used, it’s important that the putty be allowed to dry for a few days before the primer is applied.
An exterior spackle, like UGL’s 222 Spackling Paste can also be used to fill nail holes. Depending on the weather conditions, either oil or latex primer can generally be applied the same day over this product. Exterior spackle shrinks as it dries, but an experienced painter will allow for this shrinkage by "overloading" the hole being filled and sanding any proud material flush after it dries. In situations where a latex primer will be applied immediately after the holes are filled, I would use Bondo, or some other quick-hardening two-part automotive body filler.
I recommend hot-dipped galvanized finish nails for all trim work that will be filled. Wood siding should be fastened with stainless steel ring-shanked siding nails. Though more expensive, stainless steel nails are cheap insurance against bleeding and corrosion problems.
Painting contractor Stephen Jordan is the rehabilitation adviser to the Landmark Society of Western New York, in Rochester, N.Y.
