Mark’s Caulking Tips
I’ve emptied at least 5,000 tubes of caulk in my career—that’s a bead about 20 miles long! I’ve filled in gaps so flawlessly that the caulk was virtually unnoticeable, but there’s also been plenty of times that I’ve globbed things up pretty good. To help you get a top-notch caulking job with a lot less frustration, I’m going to share a few tips I’ve learned along the way.
Choose the right caulk for the job
1) Exterior siding, windows & doors
Temperatures changes cause the components on the outside of your house to expand and contract more than the ones on the inside. That’s why flexibility is an important characteristic of exterior caulk. And obviously, exterior caulk needs to stand up to sun, water, and extreme temperatures. For matching the texture of materials like stucco or rough-sawn wood, textured caulk is a good choice.
Polyurethane: Vulkem (for texture)
2) Interior painting projects
This is the one project where it doesn’t make sense to spend a lot of money. For just a couple bucks you can find a caulk that dries fast, is easy to work with, is easy to clean up, and can handle a little movement. Plan on spending more for a product with superior flexibility if you have a larger reoccurring crack in a wall corner or in a crown molding joint.
3) Kitchen and bath
Caulk in kitchens and a bathroom is often visible, so choosing a product that’s easy to apply neatly is important. It also needs to be waterproof, mold and mildew resistant. For those traits, check the label. Fast drying is a bonus.
Hybrid: DAP 3.0 Kitchen and Bath
4) Cracks in concrete
Flexibility is essential because concrete settles and moves up and down during freeze/thaw cycles (that’s why it cracked in the first place). And because you’ll likely be walking or driving on the filled crack, adhesion and durability is what your after. Whether you tool it in or apply a self-leveling product is a matter of preference.
Polyurethane: Loctite PL Concrete Sealant
Acrylic Latex: Slab (for cracks that move a lot)
Any caulk that lives on a roof is going to get hammered by the elements, so it needs to be able to survive extreme exposure to sunlight and temperature variations yet remain flexible. Solid adhesion is also key. These two recommended products can actually be applied on wet surfaces!
6) Sealing gutters
It’s no surprise that a product designed to seal gutters needs to be 100% waterproof. But it also needs to be tough, tough enough to handle the abrasion from debris and ice in colder climates. Most gutter sealants do a good job on metal gutters, but not all will adhere to plastic gutters.
Solvent (Metal or plastic): Lexel
Hybrid (Metal only): DAP 3.0 Gutter & Flashing
Notice that silicone is not one of the recommended products. Back it it’s day silicone was the most flexible, most water resistant, and held up to the elements better than most other product. But today there are just better choices available. When we asked one large manufacturer why they still produce silicone, they answered, “Silicone is what some of our customers watched their father use, and it’s what they’re familiar with.”
My favorite gun
The most expensive gun on the rack isn’t necessarily the best. Here’s what I look for: I like a gun with a cradle. Tubes seem to fall out of the guns with the rails. I prefer guns with ratchet action rather than friction action. I won’t even consider a gun that doesn’t have a hook. Forget about gun-mounted tube cutters—I’ve yet to see one of them do a good job. I use a utility knife. And if all other things are equal, buy the gun with the longer tube poker. Some aren’t long enough to work on every kind of tube.
Ride the smooth side
When one of the surfaces I’m caulking is rougher than the other, I always try to ride the tip on the smoother surface (the brick mold in this case). If you ride the middle or the rough surface (siding), the caulking will duplicate the bumps, sometimes in an exaggerated way.
Cut tips off straight
You probably learned to cut the tip at an angle. That works OK in some situations, but an angled tip limits the position the caulking gun has to be in. With a straight tip, I can swivel the gun out of the way of obstacles, and I’m able to caulk right up to an inside corner. And if you have various-size gaps to fill, cut the tip small and do the small gaps first, then cut it bigger for the larger gaps. It looks as if I’m going to gash my finger but actually I’m spinning the tube. You probably should keep your fingers clear when cutting through the tip.
I’m not a huge fan of tooling. I try to get the bead right the first time. But sometimes it’s a necessary evil. Elastomeric and polyurethanes don’t tool well—a finger dipped in soapy water is your best bet. Latex is easily tooled, and even if you screw it up, you can wipe it off with a wet rag and start over. The only time I tape off an area is when I’m working in a highly visible area, and the only time I use a tool other than my finger is when I’m working with tape.
The DAP Pro Caulk Tool Kit (No. 09125) shown above is available at home centers for less than $10. And if you get your bead close to the way you want it, my best advice is to leave it alone. It seems the more I mess with a bead, the uglier it gets.
Don’t use your wrists
Every golfer knows that the best way to keep a putter moving in a straight line and at a consistent speed is to control it with the upper body. It’s the same with caulking. Use your upper body, or even your legs, to move the tube along, not your wrists.
Salvage a wet tube
The new guy left the case of caulking out in the rain again (it’s always the new guy). Those soggy tubes are now going to split open under pressure. Before that happens, wrap some tape around the tube. I’ve salvaged tubes with house wrap tape, masking tape, stretch wrap, shipping tape—it all works. Just use whatever’s handy.
Meet in the middle
When you have a long bead to run and you can’t get it done in one shot, don’t start again where you left off. Instead, start at the other end and meet in the middle. It’s hard to continue a bead once you’ve stopped without creating a glob. I also try to keep the meeting place somewhere other than eye level.
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