Proper nail hole touchup

Using a material to fill holes that will be compatible with the finish. July 9, 2002

Question
I am a trim carpenter. Recently, a cabinet shop in my area asked me to install cabinets for them in the houses that we are trimming. All went well, but I was not satisfied with their method of filling the nail holes in the crown. The cabinets are white and they provided white tub and tile (DAP) to fill the holes. I suggested using a filler and touching up with some of their paint, as I have done with nitrocellulose lacquer. But they say it won't work with their two-part finish, because of adhesion problems. Do any of you have a better idea? I am not happy with rubbing caulk in the holes.

Forum Responses
I think filling the holes and touching up with some finish is a good idea. Even though it is a catalyzed finish, the touchup on the nail holes will get enough of a bite that it will stick with no problem. After all, they are just nail holes that will receive no wear and tear.



Use the catalyzed stuff in 24 hours or you'll have a jar of vanish that is set up the next day.


Use window glazing putty and touch up with the finish paint after. The putty will not shrink and doesn't need sanding - it works great. Learned this from an old-time painter.


From contributor C:
Over the years, the nail-hole filling technique that I've found works the best involves using Color Putty (that's the brand name). This is a linseed oil based pliable putty that comes in a very wide range of colors, and perhaps most importantly, these colors can be mixed together to match just about any species of wood.

By taking a grape-sized dollop of putty from two different colors and kneading them together, you can fine-tune a color to match the variations found within a given species. I'll often have three or four different "wads" going for an oak installation ... each one matching the different shades found in the varying color from one piece of oak to the next.

I push the putty into the nail hole with my thumb or finger, wipe off as much as I can with my finger, and when I'm done filling holes, "wash" the filled areas with a paper towel soaked in denatured alcohol. If you're patient, you really can end up with an invisible fill.

Wear a pair of latex surgical gloves when doing this - otherwise you'll spend an hour trying to clean your hands when you're through (particularly with the darker shades).

I think someone told me that denatured alcohol shouldn't be used on a particular type of finish, but I can't remember which.

I've used this technique on urethane (both oil and water based) and on conversion varnish finishes, and wouldn't think of doing it any other way (paint brushes need not apply). I get the putty at a local paint store (the kind that professional painters go to), and keep about 8 different colors on the job. If I'm installing a really weird set of cabinets (I remember one job where the finish had a blue tint), I stop by the paint store and grab a handful of colors that I know will let me create the closest match.

The Color Putty is cheap - less than two bucks a pop, if I recall correctly. If you haven't used this technique, try it - I think it'll make a believer out of you.

All that said, I think the white cabinets mentioned in the original post might present a challenge if the white color putty wasn't light enough straight out of the jar. You could certainly tone it down, but couldn't make it any brighter.

The jars pictured below are about 2-1/2 inches in diameter.




For any type of pigmented lacquer finish, we like the wax color sticks if you can find them to match your shade. When rubbed off flush, they usually have a sheen that closely matches the finish. Believe it or not, crayons actually work well for deep colors and can be melted and blended to match.


I mix my own color putty to match. Start with DAP white glazing compound, then knead in universal oil tint colors. As putty gets too sticky, add drywall topping compound, plaster of Paris, or plaster (whatever is available) and continue kneading until exact match and workable consistency is achieved. Keep finished mix in a zip-lock bag. If mix should dry out, just knead in a few drops of boiled linseed oil. Surgeon's gloves are a must for clean hands.


Contributor C, Denatured alcohol is a solvent for shellac. Denatured alcohol will take off shellac instantly. It can also dissolve lacquer if left on for a period of time. However, since the operation you recommend would not expose the lacquer for a lengthy time, it would be acceptable.


From contributor C:
Your comment is correct. Using the method I describe on a shellac finish is trouble waiting to happen. I don't know that I ever came across a "production" installation that involved a shellac finish... but if you're not sure what type of finish you're working with, it's important to confirm that it *isn't* shellac before using denatured alcohol.


Don't freak over melting through a shellac finish. They are almost impossible to screw up. Keep a little shellac around and pad it on with a soft cotton cloth. I've found it surprisingly idiot proof.

Best to mix your own - just keep some alcohol around, throw a handful of flakes in the bottom of a jar and agitate. Within an hour or so it will dissolve. Within a day you'll see a cloudy layer form towards the bottom - that's wax. You can mix the layers back together or decant the clear stuff. The wax makes the shellac more susceptible to water rings, I'm told, though I haven't been bothered.

Figure a shelf life of about 3 months for any mixed shellac, even the kind in the can. The flakes last indefinitely if kept tightly sealed.

You occasionally hear about blooming - the finish getting cloudy. This is caused by moisture condensing on the film. Just be careful about the weather. It's never happened to me with shellac, though once with padding lacquer.



The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).

Comment from contributor A:
Oil putty is not appropriate on white catalyzed finish. Use a clean, white shade of wax from Konig or Mohawk and pre-cat lacquer cans of spray with the proper sheen. Keep cans warm with hair dryer in cold weather.