How to Use a Caulking Gun

Follow these expert-backed tips for filling cracks with caulk

Do you need to make a clean, watertight seal for your current DIY project? Whether you’re sealing a tub, filling in cracks around windows, or adding a clean edge to baseboards, a caulking gun makes application so much quicker and simpler. Almost all caulking guns work the same way, so we’re able to help no matter what kind you have. Keep reading and we’ll walk you through your caulking project from start to finish.

Just here to learn how to load a caulk gun? Jump straight to the section here.

[Edit]Things You Should Know

• Cut a 45-degree angle in the tip of a tube of caulk with a knife or using the hole next to the gun’s trigger.
• Pull back the metal rod on the gun and load the tube of caulk into the gun. Hold the gun at a 45-degree angle to the crack you’re filling.
• Squeeze the trigger and slowly move the gun to apply the caulk in a smooth line.
• Run your finger over the line of caulk to fill in the gaps and smooth it out.

[Edit]Steps

[Edit]Cleaning and Masking the Area

1. Clean off all the old caulk with a putty knife. Place the sharp end of the putty knife at the base of the old caulk. Then, grab the handle and push the knife forward. Keep pushing forward until you remove all the caulk.
   
   • Alternatively, you can use a caulk removal tool or a utility knife.^[1]
   • To make caulk easier to remove, apply a caulk softener, wait 20-30 minutes, and then scrape it with a carpet or putty knife.^[2]
   • By removing the old caulk that may be cracking, you're avoiding building a new layer on weak foundations.^[3]
2. Wash the surface with alcohol, bleach, and hot water. Wet a cloth with rubbing alcohol and set it on the crack to soften any leftover caulk. Then, wet a rag with warm water and diluted bleach to disinfect the surface. Then, rinse the area with a different rag soaked in hot water. Dry the surface with a towel when you’re finished since new caulk won’t adhere when it’s wet.^[4]
   
   • Caulking traps anything inside the crack so make sure all dirt is completely removed.
   • If you see any caulk or grime left over, use a plastic scraper to lift it up.
   • If you're removing silicone caulk from tiles, heat it up with a hair dryer or apply a commercial solvent.
3. Protect the surrounding surface with painter's tape. Stick one long strip above the crack and one right below it. This tape keeps the caulk off of anything nearby so it doesn’t stick or harden where you don’t want it. It also acts as insurance in case you make a mistake later on.^[5]
   
   • Using painter's tape also makes the edges of your caulk line clean and smooth.

[Edit]Loading the Caulk Gun

1. Press the caulk gun’s release trigger to pull the rod back. Look for a small metal trigger on the back of the caulking gun where the long metal rod connects. Press the trigger down with your thumb to loosen the rod that runs through the entirety of the frame. With your other hand, pull the rod as far back as you can and hold it.^[6]
   
2. Cut the nozzle on a tube of caulk to a 45-degree angle. Use a pair of scissors to cut the nozzle so it’s about the size of the crack. If the crack is large, consider cutting the nozzle close to the tube so more caulk comes out. If the crack is small, cut the nozzle near the end to be more precise.^[7]
   
   • This choice is permanent, so think carefully about the thickness before you make the cut. It's better to start closer to the end of the nozzle and make the opening bigger if you need to.^[8]
3. Pierce the nozzle with the gun’s piercing rod or a nail. Check the front of the caulk gun for a short metal piece that folds out. Stick the metal piece into the end of the caulk’s nozzle until you feel it poke through the tube. If your caulk gun doesn’t have a small metal rod, then use a sharp nail to puncture the tube.^[9]
   
   • Check the instructions that came with the tube of caulk you’re using to see if there’s a specific way to pierce the tube.
4. Insert the tube of caulk into the gun. Keep holding the steel rod back, and put the flat end of the caulk tube into the back of the frame. Position the nozzle so it slots into the hole at the front of the gun. Squeeze the large trigger on the gun lightly to make sure the tube is snug and level.^[10]
   
   • If you need to, ask a friend or family member to help keep the rod back as you work on inserting the caulking tube.

[Edit]Applying the Caulk

1. Pull the trigger and move the gun over a piece of paper to practice. Hold the gun at a 45-degree angle with the nozzle facing downwards. Then, over a piece of paper, press the trigger at the back of the gun while moving the caulking gun steadily in one direction. The caulk will come out in a smooth, steady stream when you do it correctly.^[11]
   
   • If you move the caulking gun too fast, the caulk will look too thin and uneven. If you move the caulking gun too slowly, the caulk will be clumpy and unworkable. Take your time to find a good balance between the two.^[12]
   • It may take a few squeezes of the trigger to get your caulk gun started for the first time. Just let the pressure off the trigger and try squeezing it again.
2. Hold the caulking gun at 45 degrees to the crack. Hold the caulking gun with both hands so one is on the trigger and the other is supporting the end of the gun. Tilt the entire gun at a 45-degree angle so the caulk flows out evenly. The caulk should start to flow towards the nozzle.^[13]
   
   • Although the trigger will push some of the caulk out of the tube, by holding the gun at 45 degrees, gravity helps with the process.
3. Press the trigger to push the caulk into the nozzle. Once you push the trigger, the steel rod will push the back of the caulk tube to force it out of the nozzle. Press the trigger firmly and steadily to apply the caulk in a slow, controlled manner.^[14]
   
4. Move the caulking gun across the length of the crack. As the caulk comes out of the nozzle, slowly move the caulking gun along the entire crack. Try to move in a single, steady motion so the caulk fills the crack evenly.^[15]
   
   • If you missed any spots, don't worry. Just come back and fill them in with a second pass.
5. Smooth the caulk line with your finger. Put on a disposable glove and wet the tip of your finger with some warm water. Quickly drag your finger along the line of caulk to smooth it against the surface and create a clean finish.^[16]
   
   • Wearing a glove helps prevent caulk from sticking to your hands since it can be difficult to clean off.
6. Remove any painter's tape and let the caulk dry. Peel off all the painter's tape and leave the caulk to dry. Each caulk tube will direct you with the precise time to wait until it's completely dry. Generally, it takes at least 24 hours for the caulk to completely solidify.^[17]
   

[Edit]Video

[Edit]Tips

• Press the release trigger after applying the caulk to prevent dripping.^[18]
• Tape the caulk nozzle closed when you're finished to prevent it from drying out.
• Some caulks may be better suited for your problem than others. Acrylic caulk is a versatile and popular option for caulk, but it can shrink when it dries. Silicone caulk forms a strong bond, but it can be expensive and is hard to paint over. A butyl rubber caulk is very mobile, so it works best near hinges or doors where the caulk's going to move often.^[19]

[Edit]Things You’ll Need

• Putty knife
• Painter's tape
• Rubbing alcohol
• Bleach
• Caulk
• Caulking gun
• Scissors
• Piece of paper

[Edit]References

[Edit]Quick Summary

1. ↑ [v161695_b01]. 13 January 2021.
2. ↑ [v161470_b01]. 20 August 2020.
3. ↑ [v161695_b01]. 13 January 2021.
4. ↑ https://www.bobvila.com/articles/how-to-remove-caulk/
5. ↑ https://todayshomeowner.com/painting/guides/homeowners-guide-to-caulk/
6. ↑ https://youtu.be/C3QmFIk3EPM?t=405
7. ↑ https://todayshomeowner.com/painting/guides/homeowners-guide-to-caulk/
8. ↑ [v161470_b01]. 20 August 2020.
9. ↑ https://youtu.be/jufcpLs-Hkk?t=69
10. ↑ https://youtu.be/61CSfFkQQbk?t=80
11. ↑ https://todayshomeowner.com/painting/guides/homeowners-guide-to-caulk/
12. ↑ [v161470_b01]. 20 August 2020.
13. ↑ https://www.energy.gov/energysaver/caulking
14. ↑ [v161470_b01]. 20 August 2020.
15. ↑ [v161470_b01]. 20 August 2020.
16. ↑ [v161470_b01]. 20 August 2020.
17. ↑ https://www.thisoldhouse.com/bathrooms/21015082/laying-down-a-perfect-bead
18. ↑ https://www.energy.gov/energysaver/caulking
19. ↑ https://www.thisoldhouse.com/bathrooms/21015082/laying-down-a-perfect-bead