Dear Tim: Can you tell me how to caulk baseboards? I thought my new paint job was looking great until all sorts of black lines showed up where there were gaps between the baseboard woodwork and the walls. I don’t remember seeing that in other houses, so I must be doing something wrong. What caulk should I use? How do you get a smooth line, as my caulking always looks smeared? When is the best time to caulk if you are installing new baseboard and trim? – Kirsten P., White Plains, N.Y.
Answer: You aren’t the first person to ask how to caulk. Caulk is a building product that people tend to forget about when they do interior painting projects. But caulk is one of the most valuable products used by professional painters and those seasoned do-it-yourselfers.
Applying caulk is a fairly easy skill to master. There are many different ways to do it, but I will share an effective method I have used for years. The first thing to do is get a caulk that is easy to use and cleans up with water. I prefer to use caulk that is a blend of acrylic and silicone. Read the labels on different tubes of caulk and try to find one that says it has the least amount of shrinkage.
The tools you will need are simple: a caulk gun, a putty knife, a razor knife, a tile-grout sponge and a bucket. There are huge differences in caulk guns. My favorite is one that costs about three times what the cheap ones cost.
I prefer to caulk baseboards and trim after they have a coat of primer on them. Caulking bare wood can be problematic as it can be difficult to remove caulk from the wood grain. It is also easier to see the areas that need caulk if the wood is painted a light color. The gaps show up as the unsightly lines you currently see in your woodwork.
It’s critical to get the right size hole at the end of the caulk tube. If you make it too big, far too much caulk flows from the tube. If the hole is too small, then you work too hard to fill the gaps. I have found that a hole size just over 1/16 inch seems to be perfect.
Fill a bucket with some warm water and it’s time to begin. I usually caulk about 24 inches of gap or crack at a time. The trick is to hold the caulk gun at about a 30-degree angle to the crack and squeeze the handle so an even amount of caulk flows from the tube. You want the caulk to be slightly higher than the top of the gap or crack. As the caulk exits the tube, you slide the caulk gun along the gap. If you move too quickly, the gap will not get filled. If you move too slowly, lots of caulk will build up above the cracks.
Set the caulk gun down, making sure you release the tension so that caulk stops flowing from the tube. Use your finger to smooth the caulk. You know you put the perfect amount of caulk on the gap if there is a very small amount of caulk on the tip of your finger as you complete the wiping stroke.
Grab the sponge and squeeze the water out of it. Immediately wipe it across the caulk joint to feather the edges of the caulk and remove any excess you left behind. Rinse the sponge and repeat. Glide the sponge softly across the caulk so you don’t remove any from the gap.