How to apply perfect caulking on trim and baseboards

If you are thinking about replacing your trim, trying a board and batten project, or making a trimmed out feature wall, this post is for you! I’m giving out my best caulking tips to take your DIY project to the next level!

Today, I’m talking about one of my best friends as a DIYer: caulk! It gives any trim or moulding project a finished, professional look and hides any mistakes or imperfections.  Did you cut that last piece of trim a little too short?  Or is the wall not quite straight, leaving an unsightly gap behind your moulding? Put some caulk in it and suddenly everything looks perfect! It takes a project from blah to stunning, and it’s so affordable and easy once you get the hang of it.   

How to use a caulking gun

Everything is easier when you have the right tools, and caulking is no exception.  If you plan to do any caulking at all, a gun is worth the small investment it will cost you. It gives you more control during application, and makes opening and handling the tube much easier.

A caulking gun has several different components. The first is this little blade that you can see moving in the video when I tilt the gun toward you.  That’s the blade that cuts the top off the caulking tube. Then we have a little stick that is used to poke a hole in the top of the caulking tube after the tip is cut off.  You can also use a nail, but this stick is right on your caulking gun. And then there’s a lever that locks the gun in place.  So when you pull the trigger on the gun, it pushes the caulk out by moving the back of the gun forward. I don’t know what any of the technical terms for these parts are, because I’m a DIYer and not a professional! But you can see how useful this tool will be for your next caulking project. 

Caulking Gun Tips

1. Start by sliding the tip of the tube into the hole on the side of the gun, and squeeze the trigger to move the blade and slice the top off.  
2. Then, use your stick to puncture a hole in the tip.This stick is especially important for when you are using the caulk for a second time, and need to punch through the dried caulk to use it again.  
3. Next, put the caulking tube into the gun. Slide it into the channel, and then push the metal piece at the back forward until the tube is sitting flush with the front of the gun with no extra space. 
4. Lastly, twist the metal lever so the hook part is facing up, which will lock the lever in place.  As you can see from the video, I’ve successfully loaded the gun following these steps! 

5 Caulking Tips for beginners

1. Make sure you cut the tube properly.

When you are slicing off the top of the caulking tube, make sure you do not cut too much of it.  The wider the tip, the wider the bead of caulk that comes out. The rule is : the smaller the bead the better for trim and moulding projects.  When you’re filling small cracks to prepare for painting, you only want a 1/16 inch opening in the tube. For larger cracks, just put in an additional line of caulk instead of cutting the hole in the tube bigger. You also want to try and cut the tip at a 45 degree angle, as that will also help with ease of application.  

2. Use tape to start.

Taping the line you want to caulk is a great little hack (thank you Colleen of LemonThistle!) to use until you are more comfortable with a caulking gun. Tape both the wall and the baseboard, leaving a small gap for your caulk to go into the seam. Once you’ve applied it in the crack between the two tape lines, smooth it with your fingertip, not like you’re squishing it into the gap but just so that it’s flattened slightly against the wall.  Then, peel back the tape to get a nice, crisp line. This method is time-consuming, but it WILL help you get a straight line until you feel more confident about your caulk gun skills!  

3. Start with a clean surface

It is absolutely necessary that you make sure your surface is clean and dry before you start caulking. Make sure there is no old caulk, rust, flaking paint, dirt, etc anywhere near where your line of caulk is going to go. Using rubbing alcohol will help remove any residue and/or debris. By starting with a clean surface, the caulk will bond to the surface and stand the test of time!

4. Choose the right product for the job

Just like using a caulking gun will make things easier for you, so will using the right caulk product for the job.  In the video, I’m demonstrating with ALEX FLEX^® Premium Molding & Trim Acrylic Latex Siliconized Sealant.  This product is formulated specifically for filling gaps and holes in trim and moulding, which is what we as DIYers will be doing most of the time! It is important to read labels and make sure you get the right thing for what you want to do since there are SO many different products out there.  This is what I used to seal the trim against the wall for my dining room project and my hallway board and batten transformation,  and I am very happy with the results.  

5. Apply caulk in short sections

If you take away just one of these caulking tips, pick this one! One thing that really gets in the way of a neat and tidy caulk job for beginners is trying to apply a long line of caulk all at once.  If you keep the sections short there is less chance of making a wavy or crooked line, as you will have more control over the gun and won’t have to move yourself as often to complete it. Doing 8-12 foot runs at a time will take practice, so be patient! It’s also much easier to fix mistakes in short sections, as they won’t start to dry before you’re ready to go back to them and check they are done correctly.  Another consideration is just how much work pulling the trigger and holding the gun steady really is! Shorter sections will give your muscles a chance to rest and won’t result in broken or crooked lines caused by fatigue in your trigger hand.  

How to apply perfect caulking:

First, a recap!  We’ve covered how to:

• Purchase the right product for the job
• Get the tube ready to use
• Work the caulking gun
• Clean and prep your caulking surface
• Tape the wall and trim for a straight-line hack
• Work only with small sections 

All that’s left now is to actually DO it! Here is how to apply perfect caulking:

1. Once you’ve got your caulk prepped and loaded into your gun, make sure you have a few damp paper towels ready and within reach. You will use them to keep your fingers damp, which will be helpful when smoothing down the fresh line of caulk you are about to apply.  
2. Now,  squeeze a line of caulk along your trim, about a foot or two long. It will be tempting to go slowly, but actually the faster you go the better! Speed will ensure an even and smooth application. 
3. As you get close to the end of the section, press the release lever on your gun to stop the caulk from coming out of the tube. 
4. Now, wet the tip of your index finger on the damp paper towel, then run it along the bead of caulk to smooth it flat. Your damp finger will slide easily on the line of the caulk and won’t make marks or dents in it. 
5. Finally, any extra caulk (there shouldn’t be much, since you made sure the hole was small when you cut the end of the tube!) can be wiped off on your paper towel.  Repeat on the next short length of trim until you’re done!

That’s it! Now you have all the caulking tips you need to give your trim DIYs a professional, finished look. Tag me @mintcandydesigns to show me your finished projects!