Above all, don't let your fingers do the caulking


I have been caulking incorrectly. For years I have been using my fingers to smooth out the bead of caulk that I had put in the gap around a bathtub or a window frame. Then the other day I learned that it was risky to smooth the caulk.

Smoothing the caulk bead with your finger may make the caulk too thin. A bead of caulk that is too thin can't expand to fill the gaps. That is what caulk is supposed to do, fill gaps. But skinny caulk can't provide as much protection against water as a bead of caulk that is pooching out.

"Pooching out" is not a technical term. In technical terms you want a "convex bead." That means you want a caulk bead that bulges slightly at its center, a situation I identify with. I found it refreshing that, somewhere in the world, being pleasantly plump was applauded.

The "please don't smooth the caulk" tip was one of the many I picked up during a recent intensive review of caulk literature. This was conducted when I was sitting in hotel rooms and in airports. Other people who travel may use their idle moments to read thought provoking novels or pore over steamy magazines. When I traveled to Atlanta recently, I read about caulk and sealants.

Caulking is a hot topic this time of year. I found advice on how to use caulk to stop drafts and leaks in the Atlanta Journal-Constitution, as well as in "The Homeowner's Guide to Caulks and Sealants," a faux newspaper published by the Rohm and Haas Paint Quality Institute. Until I read its publication, I had never heard of this institute, but it turned out to be run by a Philadelphia-area company devoted to caulk.

I also discovered that there were two ways to apply caulk. The push and pull methods. Both use a caulking gun, a metal apparatus with a trigger and a plunger that pushes the caulk from cardboard tubes that have plastic nozzles. Caulking guns are cool.

I knew about the pull method. I knew how to put the tube of caulk into the caulking gun, to hold the gun at 45-degree angle, and to gently squeeze the trigger. Then I slowly pulled the gun along the gap that needed to be filled.

The new method was the push method. To use it I was supposed to hold the gun, higher, at about a 60-degree angle, squeeze the trigger and push the gun forward. The push method was supposed to put more caulk in the cracks, but was said to be messier than the pull method.

The more I read about choosing the right type of caulk, the more confused I got. There were caulks made of butyl, latex, acrylic and silicone. Some could be painted, some couldn't.

DTC Finally I memorized a phrase that I could repeat when I went to the hardware store. It was, "I want a top-quality, water-based all-acrylic or siliconized acrylic caulk." As I was practicing this phrase, Ned Gordon, a caulking specialist at Rohm and Haas, called me. I tried the phrase out on him. Gordon liked it. He said if homeowners chanted those words in a hardware store they would end up with a tube of $3 caulk that would be suitable for most home repair projects.

We talked about where to caulk. Gordon, who confessed that he might be "caulk-obsessed," ticked off a list of spots around the home that were likely to benefit from a shot of caulk. If there is a half-inch gap between your marble steps and your rowhouse, he said, you could fill it with an acrylic sealant. If the gap is wider than that, use a mortar-repair sealant.

We also talked about caulking around electrical outlets. I couldn't figure out why anybody would want to do that. But Gordon said he caulked around an electrical outlet on a lamp post outside his house. The caulk bead, he said, kept rain water out.

People have been known to caulk around the edges of electrical outlets inside homes to block drafts, he said. The best product to use to stop drafts from an interior electrical outlet is something called a foam sealant, Gordon said.

Before he hung up, Gordon invited me to visit Spring House, Pa., where he and his colleagues study caulk at a house called "an exposure facility." "We've got some samples of 30-year-old caulk," he said.

I don't think I will make the trip. My house is filled with old caulk.

Besides, winter is coming and I've got to stop reading, load up my gun and get caulking. This year I've got to try to break an old habit. This year I've got to try to keep my fingers out of the caulk bead.

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