By
Matt
December 31, 2021A caulk gun is a handy tool that every DIYer should learn how to use. You can use it to seal up leaky windows and doors to prevent water damage. It's also perfect for giving you that professional look on your baseboard, trim, and molding in your home.
If you want to learn how to use a caulk gun, then you're in the right place! In this article, we'll walk you through all the steps. You'll learn how to pick the right caulk for the job and how to use a caulk gun like a pro.
You'll also learn practical tips to master the art of caulking and impress your friends. Okay, that last bit was a stretch. But we're sure you'll learn something valuable!
Ready? Let's dive in!
The first thing you need is some caulk. But what type do you need?
It's easy to get confused because the caulking tubes say all kinds of things on their labels. Some say "designed for kitchens and bathrooms," "100% silicone", "100% waterproof", "mold-resistant," or "windows and doors." Which one do you need?
Let's start with our rules of thumb. These rules should answer most of your questions and help you choose the right caulk for your job.
Rules of Thumb on How to Choose Caulk:
Now, if that's all you need, you can skip ahead to step two. But if you want to learn more about different types of cauk, then keep reading.
Silicone caulk is very flexible, and it allows for a high degree of expansion. It's also resistant to water and temperature fluctuations. Additionally, because silicone is inorganic, it's resistant to ultraviolet rays and won't quickly deteriorate in the sun.
You can also apply silicone caulk in a wide range of temperatures, from about -35 to 140 degrees Fahrenheit. It also performs well in hot and cold climates and has a long lifespan of around 20 years.
The main disadvantage of silicone caulk is that it's difficult to clean off certain surfaces. It's great for non-porous surfaces, such as glass and in your kitchen and bathroom. But it's a terrible choice for wood, brick, and stone. You also can't paint silicone, and it picks up dirt easily.
Also known as painter's caulk, acrylic latex caulk is the go-to choice for caulking inside your house. It's paintable, and cleanup is easy using soap and water. Just like silicone, acrylic is also very resistant to ultraviolet rays.
Some chemical formulations of acrylic caulk are water-resistant and can also withstand large temperature ranges from -25 to 175 degrees Fahrenheit.
The main disadvantage is its limited movement capacity, ranging from 7.5% to 25%, depending on what additives are included in the chemical composition.
It also takes up to 10 days to cure and form a waterproof seal. This means you can't get it wet while it's curing. Finally, if you plan on using acrylic caulk outside, you have to apply it in temperatures above 40 degrees Fahrenheit, unlike silicone, which has a much wider application range.
In the caulk aisle, you might also see some tubes of acrylic caulk that contain added silicone. It's still paintable like normal acrylic but features increased flexibility like silicone.
You can use siliconized acrylic caulk inside and outside, especially in areas you want to paint. It still needs a few days to cure (so don't caulk when rain is expected). Also, cleanup is slightly more involved and requires a solution of isopropyl alcohol and water. But it's still easier than pure silicone.
Polyurethane caulk is a flexible caulk designed for outside use. It's great for moisture resistance and designed to expand and contract with changing temperatures. The main benefit of polyurethane over silicone is that you can paint it to match your house or surrounding area. It's also less expensive than silicone.
Sounds great, right? Well, it's not without its drawbacks. Unlike silicone, polyurethane caulk breaks down quickly under extreme temperatures and extended UV exposure. However, some formulations are treated with UV absorbers to improve performance in locations exposed to the elements.
Sometimes you'll see an exterior caulk that doesn't say what's inside the tube. OSI is a great example. It's a fantastic caulk and trusted by contractors for all types of outdoor caulking jobs. But the package and SDS doesn't list silicone as an ingredient. Maybe it's more like polyurethane because it's paintable? But the product literature says it's UV resistant and it carries a long warranty.
You can apply OSI when it's freezing, on wet surfaces, and even in the rain! It also comes in thousands of colors! Literally thousands!
OSI is just one example (the most popular choice), but many other types of comparable elastomeric sealants have similar attributes.
The main drawback to these heavy-duty caulk sealants is removal. It's almost impossible to get it all off. But the upside is endurance under extreme outdoor conditions.
Butyl rubber is an elastic caulk best used around roofs and shingles. It's designed for wet areas and extreme temperatures.
You can try using mineral spirits for cleaning it up, but it's still going to be hard. The service temperature allows for installation in both hot and cold temperatures, and it's designed to last about 10 years of exposure.
A flexible and elastic caulk is used for patching cracks in driveway asphalt. It provides long-term crack repair easily stands up to rain and extreme temperatures.
Most asphalt caulk brands go on gray but dry black to blend in fairly well with your driveway.
The most common mistake that some homeowners make is to apply a non-fire barrier caulk in areas that require a fire stop. If you aren't already familiar, a fire stop is a passive protection, which impedes smoke and fire spread in a building.
The most common places to use fire barrier caulk is around fireplace exhaust vents, pipes, cable penetrations, and any other areas as required by code.
You should find out where you need it before buying a few tubes because it's costly.
A mortar repair caulk is designed for filling gaps and cracks in concrete and mortar around your home. It comes in different formulations, and it could be made from silicone, rubber, or acrylic. Try to avoid mortar repair caulk that includes polyurethane because it could break down due to increased UV exposure.
The type of caulk gun you need depends on the caulk you plan on using and its viscosity.
A thicker and slow-moving caulk has low viscosity and needs more power to get it out of the tube.
A thinner and fast-moving caulk has a high viscosity and needs less power to get it out of the tube.
Cheatsheet on How to Choose the Right Caulk Gun:
A common question we see a lot is which caulk gun should you choose if the label doesn't say what's in the caulk? In that situation, the rule of thumb is to choose based on the location where the caulk is meant to be used.
By the way, if you don't have a caulk gun or you're looking to upgrade, then check out our reviews of the top models for this year. In these articles, we cover ratchet, smooth, and cordless caulk guns.
The best way to achieve a high-quality seal is by taking the time to correctly prep the area you want to caulk.
Use a utility knife, razor blade, scraper, or plyers to remove the old caulk to the best of your ability. The more old caulk you remove, the better the new caulk will adhere and seal.
Clean the area and make sure it's free of dirt and debris as these things can inhibit the fresh caulk's performance. If you're planning on using silicone, then make sure to clean the area of all paint; otherwise, it won't stick.
If you're dealing with a bathroom or kitchen, you can also perform an extra cleaning using a 1:1 mixture of isopropyl alcohol and water. Use a rag moistened with the mixture to clean any dirt, grime, or remaining caulk. As always, test the solution on a small area first to ensure the mixture doesn't damage the surface.
You can also try using a hairdryer if you have some stubborn caulk that won't come off. Just be extra careful because you don't want to melt anything near the caulk. The goal is to warm up the caulk enough, so it's easier to remove.
If you're caulking your kitchen or bathroom, you might want to use painter's tape or masking tape to section off the area. Tape off the area above and below where you plan on caulking, leaving only the seam exposed.
The benefit of masking off the area is that it creates a fantastic looking bead of caulk with little cleanup. Just smooth out the bead of caulk and then pull off the tape.
But the downside to using tape is the labor involved. Taping an area is a very time-intensive process. Also, if you're somewhat experienced at caulking, taping isn't really necessary. The trick is only to apply enough caulk (not too little and not too much). If you can do this, then you'll have a perfect bead with almost zero clean up.
After prepping the surface, it's time to cut the nozzle to open the tube. But before we start, let's get some terminology out of the way. As you work, the line of caulk that you create is called a bead.
Now, look at your tube of caulk. Notice how the tip is tapered and comes to a point? The closer to the tip that you cut, the smaller the bead of caulk you'll create. If you want a larger bead, then cut down lower on the tip for a larger opening.
How far down should you cut? Less is always best! As you smooth out the bead you made (later in these steps), you'll quickly learn that excess caulk easily smears and gets messy.
So the trick is to cut the tip at the right spot to create a bead large enough to cover the gap in whatever you're caulking. You can always trim a little more off the nozzle if needed.
When you cut, avoid the common mistake of cutting the nozzle tip perpendicular to the tube. Don't do this! Instead, cut the tip at a 45-degree angle, which helps create a nice bevel as you caulk.
If you've made it this far then, you're ready to cut! We recommend that you use a utility knife with a sharp blade. You could also use a spout cutter if your caulk gun has one integrated into the handle.
After you've cut, you can optionally use sandpaper to remove any extra burr.
The last step you need to take before inserting the tube into your gun is to pierce the seal inside the nozzle. Not all tubes have a seal, but some do, and caulk won't come out until it's pierced.
Some caulk gun manufacturers integrate a rod into the gun for this specific purpose. If your caulk gun doesn't have a piercing rod, you can also use a coat hanger or one of those yard flags with a metal rod.
If you're using a rod attached to your caulk gun, then make sure to wipe it off after piercing the foil. If you don't, the caulk on the rod will spread. It will get on the gun, on your hands, on your clothes, on your dog, and it's hard to get off once it dries.
It's time to load a tube of caulk into your gun.
If your gun is a smooth rod style, then pull back on the push rod. Pull it as far as it will go towards the rear of the gun. If you have an older ratcheted rod gun, then you'll have to flip the rod 180 degrees before it starts moving. If it still doesn't move, then check for a release trigger on the frame.
Once the plunger reaches the back of the gun, try inserting the tube of caulk. If it doesn't go straight in, you might need to put the nozzle end in first. Some caulk guns have metal rims on the front of the cartridge slot. These rims prevent the tube from falling out when loaded in the gun's cradle. But they can also make it tricky to load a new tube.
After inserting the tube, slowly push in the plunger until it touches the bottom cap of the tube. Make sure it doesn't apply any pressure to the tube yet; otherwise, caulk will come out.
Okay, you're ready to start caulking! Place the nozzle at a 45-degree angle against the surface you want to caulk and gently squeeze the trigger, applying steady pressure.
If you don't see caulk coming out of the tube right away, be patient, and don't squeeze harder. It takes a moment or two for the caulk first to fill up the nozzle before it comes out.
Try to create an even bead and a bead size large enough to cover the gap. But be careful not to apply too much because it can make cleanup difficult. Start with a small amount and then gradually work your way up, always applying light pressure.
If you need to adjust the caulk amount in the gap, you can change how fast you move the caulking gun. But it's always best to move at a medium to slow pace. You could also try adjusting the pressure that you're applying to the trigger.
Finally, make sure that you only move the caulking gun in one direction as you work. You'll screw up your bead of caulk if you move the gun back and forth.
After you finish caulking a section, you might be wondering why your caulk job doesn't look professional. It's probably because you need to smooth out the bead.
If you bought a caulking tool such as a putty knife, return it for a refund. It can't compete with the soapy finger method! All you need for the soapy finger method is a bottle of clear dish soap, a roll of paper towels, and your finger.
Start by pouring a tablespoon of clear dish soap into a small bowl. It would be best to use clear soap because it remains invisible on the caulked surface, unlike tinted soap.
Now take your pointer finger and dab it into the bowl. You don't need a lot of soap, just a small amount. The soap prevents the caulk from sticking to your finger and allows you to smooth out the bead without pulling it out of the gap.
The next step is to take your coated finger and place it at a 45-degree angle on the bead of caulk. Then gently drag it along the bead in one direction. You should see the caulk filling the gap and getting smooth!
CAUTION! Here is where you need to be very careful if you didn't use tape to mask off the area. As you drag your finger across the bead, the excess caulk will start piling on your finger. Eventually, you'll reach a point where too much caulk is on your finger, and the excess is now starting to move up the sides of the surface!
To avoid this problem, you'll need to wipe your finger off regularly using the paper towels. When the excess starts getting too much, wipe your finger, dab it in the soap again, and continue where you left off.
As you continue to caulk, you might run into a few situations you aren't sure about. Here are some of the most common things when using a caulk gun and the best ways to handle them like a pro.
You might find that when you release the trigger to stop caulking or take a break, caulk still oozes out of the nozzle. The reason this happens is that the plunger is still applying pressure on the back of the tube.
The solution is to relieve pressure on the tube by disengaging the plunger. You might have to press a lever on your caulk gun to relieve the pressure, or you might have to pull back on the plunger slightly.
Some newer dripless caulk guns don't have this problem because they feature drip-free technology. The moment you release the trigger, the plunger automatically slides back and relieves most of the pressure on the caulk tube.
It's effortless to remove an empty tube of caulk from the barrel.
Start by pulling the plunger all the way back. Try to pull it as far back as when you loaded the tube at the beginning.
Then pull the tube of caulk out of the gun. You might have to lift from the end of the tube, depending on the model of the caulk gun. Some models feature metal rims on the barrel, which prevents pulling the tube straight out.
What if you finish caulking or want to take a break and the tube still has some caulk left?
You can definitely save the caulk for later, but you have to seal the tip properly. If you don't seal the tip, then the caulk in the nozzle can dry, and dried caulk is tough to get out.
Common ways to seal a tube of caulk:
Gum - If you've been chewing some gum, spit it out and cover the nozzle. It sounds disgusting, but it works. Just don't reuse the gum when you're ready to caulk again.
Plastic Wrap - Wrap the nozzle tip in plastic and then use scotch tape to seal the bottom of the wrap to the nozzle.
Tack or Silly Putty - Using tack or silly putty to seal up the caulk tube works great. Both of these substances don't dry out like chewing gum. The caulk will still be fresh even if you pull them off months later.
Drywall Screw - You can also try shoving a drywall screw into the tip of the caulk tube. It can rust, so it's not a permanent solution. But it works great in a pinch!
Siding Nail - If you don't have a drywall screw, try a siding nail if you have one lying around. Most siding nails are aluminum and won't rust in the tube.
Plastic Caps - Most home improvement stores sell packages of plastic caps for sealing tubes of caulk. You can usually pick up a pack of five for a few bucks.
Big Glob of Caulk - The last thing you could try is leaving a big glob of caulk on the tip of the nozzle. It will prevent the caulk in the nozzle from drying out, and it will give you something to grab onto and pull out any dry caulk.
The most important thing you should do is to keep your caulk gun clean. It's probably the last thing you want to do after finishing a long job, but it's an essential step to prevent caulk buildup, which is hard to remove when dry.
Key areas to clean include the piercing rod, plunger, handle, and the squeeze trigger. You should also make sure to keep the spring mechanism clean otherwise, it will hinder performance.
Usually, a wet rag is enough to rub off any caulk. But you might have to use some rubbing alcohol or vinegar for stubborn caulk. For dry and hardened caulk, try using a wire brush.
Overall, the cleaning process should only take a few minutes, and you'll be glad you did it next time you pull out the caulk gun for another job.
Are you shopping for a new manual caulking gun? Here are some of our favorites that we want to share. Also, if you need some help, then be sure to check out our detailed buying guide. It explains some of the important considerations when shopping for a manual caulking gun.
