I have had to do a lot of touch-ups on a place that was a photography studio. There are close to 100 nail holes on every wall and most of the walls are 20 feet by 12 feet. The nail holes are all sizes. The owner did not want to use a primer, figuring that the majority of the spots were so small that it would not be a problem, so we decided to use 20-minute mud for patching, then we sanded and painted almost as soon as the mud dried.

The problem is that all of these little spots are flashing through the walls. The larger patches show through because of differences in the texture of the surrounding wall, which has had several coats of paint applied over the years. So you have roller texture and smooth drywall patches. I also noticed that the 20-minute mud seems to sand to a more polished finish than regular mud.

Any suggestions on how to make the patches disappear? —m beezo, St. Louis

High-build primer with a 3/4-inch lambs wool roller. Then one to two finish coats. On problem areas, lock it up first with oil-based [Zinsser] Cover Stain and lightly skim with a light drywall compound. When dry (about one hour), prime again, then apply a finish coat.

I think even if you used high-build primer over all those holes it would still flash. I seem to have to pull a tight coat of ready mix over all hot mud on random patches, then prime/texture with a roller. —Happy Home, Greensboro, N.C.

I do small patches only with “topping” or AP mud—they really do not take that long to dry on small patches. And I have always primed touch-ups. When I have not primed, larger ones have shown through. —Davenorthup

We deal with this a lot, and there are a few issues involved.

When you skim pops or joints, it is tough to rush it or skip a step. The hot muds dry harder and the sand more polished. Whether you use regular or quick mud, it’s important to prime. If you don’t prime and just paint over them, the patch has a different rate of absorption from the surrounding painted wall. It sucks the sheen in and creates a low flash condition. Meanwhile, you are adding to the sheen of the rest of the wall. It can look OK when viewed straight on, but from angles, it kills.

We use a mini roller and regular drywall primer. Then we set up another mini roller in the paint and feather again. Then we paint the whole wall.

One critical step is the use of rollers (not brushes) for feathering. This way you build up and blend roller texture to match the field of wall. It’s a blending exercise of sheen and roller texture. The idea is to make it disappear from all angles in all light conditions. The skimming and sanding have to be right on because even a slight bulge betrays it all. It’s helpful to put a square or a level over the patch during sanding to ensure a flush surface. Hope this helps. —Scott Burt, Topcoatfinishes, Vermont

Thanks for telling me what I thought I was going to hear … No primer is a mistake, but again, the owner’s call. Now he is hoping we can do a second coat and hoping it hides. I am not so sure. I am leaning toward a system like Scott mentioned with a mini roller to feather in some paint to give it some texture and help hide things. Only on the biggest areas since it seems to be a money issue with the guy. —m beezo

I am sure: It won’t hide. You can keep piling on the finish coats, but without a sealer, it’ll just keep flashing. —Frenchie, Brooklyn, N.Y.

Absolutely 100% correct. I had a friend who had a contractor do an addition for him. The contractor swore up and down that primer wasn’t necessary, and he painted the inside of the addition. Three coats, four coats, five coats later and it still looked like crap. All the spackle areas bled through. My friend fired the guy after the fifth coat and a month of BS, and primed and painted it himself. Took two coats after priming, but it finally looked right. —always-learning, N.J.

Follow Scott’s advice. He is spot on. I hope you are charging for all the re-do work since they didn’t allow you to do it properly the first time. It is OK for them to save money as long as they are not taking it from you. —Kgphoto, Los Angeles

I always spot texture (water-based) prime with Glidden PVA, then paint. Regular primers and even some PVAs are often too thick (almost like paint) and give me problems because they create their own little patch of smoothness by leveling too much of the repair and surrounding areas. —scott2000

Live and learn, Beez. A few months ago I did a bedroom chair rail and quoted paint in the owners’ choice of color for the whole room. They picked a green pastel. Put the first coat on and about a dozen spot patches showed through. Had to re-skim them with Lite. My mistake, I thought they were going to go with off-white that had been there. —Happy Home