The Un-Touch-upables: Tips for Effective Touch-Up

Drywall installation in gymnasium Here’s a painter’s nightmare: he’s just finished applying the topcoats in a shiny new office complex. One of the guys moving in the mahogany conference room table slips, and SMASH! what had previously been a perfectly painted bright red wall adjacent to a window beaming with sunlight now has a gouge mark clear down to bare drywall.

So it’s time to touch-up. First, the gouge mark must be repaired with white drywall filler, which will absorb the coating at a different rate than the finished wall. And even though the finish was flat, the touch-up may remain visible because of the critical lighting conditions created by the window. It’s highly likely that a complete edge-to-edge repaint will be required.

Not all touch-up jobs are this tricky. But if touch-up work isn’t done properly the first time, the costs in time and money can add up. So whether the substrate is drywall, wood, steel or plaster (doors, door frames and trim, ceilings or walls, etc.. ) here are some best practices to assure touch-up work that is essentially invisible.

Tips for Touch-Up

It’s a common occurrence in construction work for surfaces that the painter meticulously coated to get damaged or marked, either when furniture is moved in or an unforeseen construction modification is required. The painter thought the job was finished, but the GC, architect, or owner’s representative does a walkthrough and points out the defects that must now get touched-up

We evaluate the quality of touch-up work by viewing the surface from 3 feet (1 meter) away at both a 90 degree and 45 degree angle, in whatever the permanent lighting conditions will be. If the touch-up is not visible under these circumstances, it’s deemed a success.

When touch-up is not done properly, “flashing” will occur. Flashing describes the non-uniform appearance of the coating due to noticeable variations in the color or gloss, produced by a variance in coating absorption by the surface or changes in application method (e.g. brush to roller).

Generally, coatings with higher gloss and/or deeper color will be more difficult to touch-up successfully; in fact, it may be impossible. Finishes from flat to eggshell (MPI Gloss Level 1 and 2, in some circumstances Level 3) may be effectively touched-up so long as you observe these “like over like” requirements:

  • Use the same batch for touch-up: This ensures that the color will be identical.
  • Use the same type of tool: If the surface was rolled with a 10-mil nap roller, a 10-mil roller must be used for the touch-up. The roller used for touch-up can be smaller, but the nap must be identical. If not, flashing is virtually certain to occur.

Far too often we see this rule ignored. A well-meaning worker will use a brush or foam-tipped applicator to touch-up small defects on a rolled wall. The difference in the finish texture will be painfully visible.

Touch-up must also be done with the same care and technique as the original application; frequently we see touch-up coats slopped on, which can make the problem worse. Furthermore, effective touch-up may require multiple coats.

Sanding the Surface

When touching-up damaged surfaces, note that if the mark changes the profile of the surface (e.g. “makes a dent”) the surface must first be made level by sanding; otherwise the best touch-up work will still be visible. It’s a very common error in touch-up to paint without sanding the surface first. In theory, touch-up does not require sanding if the substrate itself has not been disturbed, but in our experience, almost all marks include some kind of surface damage.

For drywall surfaces, filler may also be required; and if a damaged drywall area is greater than 3 square inches, the damaged area must first be coated with a drywall primer/sealer .
If the touch-up craftsman failed to observe the “like over like” rule described above and used a brush to touch-up a rolled wall, the touched-up area will now have brush marks that will telegraph through any additional coats of touch-up material, even if the new repairs are done with the same tool as the original finish. So fixing the touch-up must begin by sanding off the brush marks.

Dealing with Sprayed Surfaces

So when is it unacceptable to touch-up a surface? Any surface that is sprayed with a semi-gloss or gloss finish (MPI Gloss Levels 5 or 6) cannot be effectively touched-up.

For sprayed surfaces that are lower gloss (especially ceilings or other areas that can’t be viewed at close quarters) it’s plausible to touch them up with HVLP spray equipment. We often see ceilings coated with dry fall that are later modified with a new pipe or fixture. Sometimes these surfaces can be successfully touched-up with careful spray work.

Doors can present a special challenge for touch-up. Doors are often airless sprayed with a semi-gloss or gloss finish. If so, a mark on the door will require a complete, edge-to-edge recoat, and the time required to rectify the problem will multiply if there are multiple doors in the area. Here’s an example: one side of one door gets marked while the carpet is being installed. At this stage, spray painting for touch-up will not be permitted on site, nor will the owner allow doors to be removed and taken offsite to be sprayed. In this case, both sides of the door need to be re-finished edge-to-edge by either brush or roller.

Now, the rolled surface will have a different stipple and color than a sprayed door. If the marked door was part of a double set of doors, or if there are additional doors adjacent to or clearly visible from the door with the mark, these will also required a complete edge-to-edge recoat.

The intrepid inspector was on a project that required a vast array of ornate wood trim and molding that was spray-finished before and after installation with a perfect airless sprayed satin finish. However, during the final construction phase, some parts of the trim were damaged and marked. The painter didn’t heed the “like over like” rule and touched-up the damaged areas with a brush. Ouch! The “repairs” could now be seen from across the room.

The irate owner called in the paint inspector for help. His solution? Tape the wall areas around the trim corner-to-corner, cover all floors and adjacent surfaces, and sand out the brush marks. Then, meticulously re-spray the damaged areas with an HVLP system that offered the lowest possible pressure with maximum control. The resulting repair was a success, but at a cost of time and money that neither the painter nor the owner had ever anticipated.

The moral of the story? If touch-up work is not done correctly to begin with, the time and costs required to fix the problem can escalate quickly. Furthermore, whether a surface can be touched-up at all depends on a range of factors including the finish’s gloss, color, method of initial application, and its location, especially where critical lighting is involved. Be warned that what worked in one area won’t necessarily work in another.

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