July 5, 2008
Tips for Good Caulking
ONE SQUEEZE OF the trigger can put the finishing touch on a project or create a huge mess. Anyone who has loaded a caulk gun is aware of the slim margin of error between a bull's eye -- a smooth bead -- and a blank: a sticky glob.
For a homeowner, caulk is a wonder substance. It seals inside and out, on the roof and in the basement. From bathtubs and baseboards to doors and windows, the list of uses for sealing and adhering is almost endless. But it takes a steady hand and preparation to keep from caulking on the wild side.
Two tips before you begin: Get the right caulk for the right job and take the time to prepare the surface. Caulks are often labeled for their specific uses: Tub and tile, doors and windows. Scraping away old caulk and cleaning the surface before application is almost always crucial to setting a smooth bead.
In most cases, caulk comes in two types: latex and silicone. Latex caulks are a combination of latex (synthetic rubber), acrylic (flexible plastic) and water. Water-based caulks are the easiest for homeowners to use because, like latex paints, they clean up with soap and water.
Silicone caulk is non-water-based and can be a bit of a struggle for some homeowners because it cures rapidly and can't be cleaned with water. You shouldn't be afraid to use silicone, however, because it cleans up nicely with mineral spirits. The major ingredient in silicone caulk is obvious, and because of this ingredient it has strong adhesive properties. If you use it to stick two things together, you're going to have a heck of a time getting them apart.
Manufacturers make buying the right type of caulk rather simple. In addition to labeling for specific uses, some caulks can be painted over after they dry and used for both interior and exterior jobs. Most manufacturers make a few different colors, including almond and gray. Clear caulk also is available if you can't match colors. Caulks with specific uses often cost a bit more. Caulks that seal bathtubs and sinks will most likely be silicone-based. In most cases, paint won't adhere to them, and they contain mildew-resistant ingredients, too. Caulks that seal around baseboards and molding are often acrylic latex and can be painted over.
Before applying, clean the surface. For tile and bathtubs, remove the soap scum and rinse thoroughly. A utility knife, industrial razor blade or putty scraper can be used to remove old caulk and loose grout. When doing this job, avoid scratching or marring the surface. On exterior doors, windows and other painted surfaces, remove loose caulk and paint with a scraper or wire brush, then clean the area with mild soap solution. You should caulk when the surface is dry. Quite often, the preparation takes longer than the application.
The best way to apply caulk is with a gun, which secures tubes (usually 10 to 12 ounces) and then uses a plunger to push caulk through a nozzle. Caulk also comes in toothpaste-size tubes with screw-on nozzles, and these are OK for tiny touch-up jobs. Whether using a tube or gun, you'll probably need some paper towels, a small bucket of water or container of mineral spirits and a sponge when applying the caulk.
Guns usually run from about $5 and up, and caulk can be inexpensive, from $2 to $3 a tube. To start, insert the tube into the gun, then push in the plunger to secure the tube. Cut the nozzle at a 45-degree angle -a smaller cut is better-and insert a long nail or wire to puncture the seal inside the nozzle.
The keys to a good job are working slowly and squeezing the trigger with steady pressure while simultaneously moving the gun along the opening. Carpenters and plumbers with years of experience have trouble caulking, so don't feel too badly when you mess up. Try practicing with inexpensive caulk on two pieces of wood nailed together at a 90-degree angle.
A smaller 45-degree hole in your nozzle will provide for a neater job. But the size of the hole in the nozzle often depends on the size of the crack or opening that needs filling. A good tip is to make your nozzle hole about half the size of the crack or crevice.
Tooling is the way to finish the bead. To be able to apply caulk and allow the nozzle to tool the bead is a skill only few can achieve. Often, a wet finger is run along a bead of latex caulk to finish the bead.
When using a silicone- or non-water- based caulk, a finger can be used, too, but it's a good idea to wear tight- fitting latex gloves when applying and finishing with silicone. If you'd rather not use a finger, try using a popsicle stick or a wooden tongue depressor to finish the bead. (A wet finger is best, though. Keep your finger clean by wiping it with a moist paper towel. Clean excess caulk with a moist paper towel.)
One trick for smooth applications is masking tape. Run tape along each side of the opening; the space between each strip should be as even as possible and about the size of the finished bead of caulk. Caulk the opening, working slowly. When you're finished, tool the bead with your finger. Wait until the caulk starts to cure (it'll be slightly tacky), then remove the tape slowly. You'll be left with a smooth bead and straight edges.
Copyright © 2008, Newsday Inc.
