A common occurrence with the installation of baseboards, moldings, trims, and other finish carpentry projects is that you may have to fill the holes left by the nails.
Painting over such holes can be problematic without a substance inside to fill the hole.
Caulk has many different uses. But can it fill nail holes left in trims, walls, drywalls, ceilings, and the like?
Key Takeaways
- Nail holes can be filled with caulk, although spackle or wood putty will be better on wood trims, baseboard, furniture, etc.
- Caulk is not recommended for filling nail holes in areas where appearance is important since the caulk has a tendency to shrink.
There are certain aspects of caulk that you need to be aware of before you start filling up nail holes with it.
Filling Nail Holes in Trim, Baseboards, and Crown Molding
Most trims, baseboards, and moldings are attached using a 15 or 16-gauge finish nailer. This will leave a visible nail mark that needs to be filled before painting.
Avoid using caulk to fill larger nail holes because the acrylic-latex caulk will shrink as it cures, and it will leave a visible mark after painting.
The 100% silicone sealant has low shrinkage, but it is not paintable and would be difficult to match the color.
You could use a hybrid latex-silicone caulk, but it still shrinks to some extent. Besides, you cannot sand the caulk to a smooth finish for painting.
Caulk vs. Wood Filler vs. Spackle
Wood fillers, putty, and spackle are generally better to use than caulk for the simple reason that it is specifically designed to fill holes, small cracks, and depressions in the surface of the wood.
Wood Fillers
Generally, wood fillers are for unfinished wood or bare wood. If the lumber that you use for building your project has flaws, cracks, and pores, you can cover them with wood filler. Once cured, you can sand the filler and paint it.
Wood Putty
A common method to fill the nail hole on unfinished wood is to use wood putty. It is easy to apply, and it cures hard. You will have spent time sanding before you can apply the finish or paint it.
Putty is also available in the stick or pencil form which looks like big crayons hence some people call it wax sticks. These work best to fill nail holes on finished trims and furniture.
Spackle
Lightweight spackle is another excellent choice for filling nail and screw holes. Spackle is not as hard as putty and is easy to work with.
A very popular product for nail filling is the DAP DryDex. Don’t be fooled by the pink color, it turns white as it dries. The pink spackle is easy to work with and can be sanded effortlessly.
The initial drying time is relatively fast, but you need to wait at least a couple of hours to 5 hours before you can paint over it.
Push the pink DryDex into the nail hole using a putty knife or your finger. After a couple of holes, go back to the initial holes and wipe off the excess with a rag. Wait for a 2 to 3 hours and sand the surface smoothly with a sanding sponge, wipe off the dust, and paint it.
Caulk as Nail Hole Filler
Sealant and Caulk are designed to act as sealing that prevents moisture from entering inside.
Caulk tends to be messier and less accurate in terms of applying it to a nail hole. This is mainly because the caulk comes in a tube and is applied by a caulk gun designed to fill long, thin cracks or openings.
Another issue with caulk is that it tends to shrink, especially acrylic caulk, which means you will have to use more of it to fill the nail hole adequately. However, while the silicone-based caulk is less likely to shrink, it is also not suitable for painting unless it is stated right on the label.
Glazing
For trims, you can also use window glazing to fill nail holes. The advantage of window glazing is that it dries fast and is paintable.
Can You Use Caulk to Fill Holes in Walls?
Caulk is designed to fill cracks and separations in walls, so it can also be used to fill holes. The key is to apply the right type of caulk that is less likely to shrink and has enough adhesion to be painted over.
Holes and Cracks in Drywall
The right method to fill the holes on the drywall will depend on the size. I would not recommend using caulk to fill holes in sheetrock.
A lightweight spackle is the best way to fill the nail holes in drywall. You can spot-apply with your finger or use a spatula (putty knife) for best results. Once dry, you can sand it and paint it over the area.
For larger screw holes, you may want to apply drywall mud or joint compound, and for even bigger holes, you might need patches and backing.
For long cracks at the joints where you have the risk of moisture entering inside, caulk is preferred since it is designed for that purpose. The joint crack is often the result of seasonal changes, and the caulk is flexible enough to accommodate these changes.
You apply the hybrid paintable caulk using the caulk gun across the crack, smooth it, and let it dry. You can then paint over the entire drywall. The result should be so smooth that no one can see any difference between the drywall and where the crack was located.
Nail Holes in Plaster Walls
For plaster, the question will be whether you are painting over it or not. If not, then you need to find a caulk with the same color if possible.
Once you have that caulk, wet your fingers, and apply a little to your fingertips. Then rub the caulk into the hole and let it dry.
Dan Miller is a professional toolmaker with extensive experience in the metalworking and tooling industry.
An avid DIY enthusiast and passionate hobbyist woodworker, Dan shares his expert knowledge here.