Interior Caulking
Adds a Finishing Touch

Interior caulking involves filling all cracks and gaps in the trim and walls. This will add dramatic improvements to the final appearance of any painted surface.

The objective is to fill every crack in the trim and every gap between the walls and the trim. Most painted trim I deal with is painted white or off-white, and dark cracks show up easily. Filling these cracks will produce a very desirable, finished look.

Siliconized acrylic caulk and elasomeric caulk work great. These two types of caulking is easy to tool, dries quickly, readily accepts paint and clean up involves only warm water. Plus high quality sealants only cost a few dollars per tube at most. Carefully read the product label to be sure it is paintable and will be suitable for your needs.

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Click To Enlarge

Using a Caulking Gun is Very Simple

Cut the plastic tip to the desired size with a razor knife, at a 45-degree angle. At first, use the smallest size hole possible. No need to waste the caulk and create a mess. 1/8 of an inch hole usually works best. Don’t start with a large hole. Cutting more of the plastic tip can increase the thickness of the bead.

If the tube has an inner foil seal, puncture with a thin piece of wire several times.

The gun is as important as the caulk. Choosing a good caulking gun will make this task a lot easier and more enjoyable. Plus help produce professional looking results.

Applying Caulk to a Crack or Gap.

Many cracks and gaps will need filling. The best approach is to use a fluid motion with the least amount of pressure on the trigger.

Hold the gun with the tip flat against the crack and pull towards you. Remember to use the smallest pressure on the trigger necessary to lay down a uniform bead. With practice this will become easier.

Now run your finger the length of the bead to press the sealant into the crack and smooth the transition between the trim pieces. For an even smoother look use a soft, damp rag over your finger while smoothing the sealant.

Remember to rinse often and frequently change the position of the rag on your finger. Have a gallon bucket with clean, warm water near by.

This method works great if the right amount is applied. If too much caulk is applied, you will have to work quickly to remove the excess and smooth the bead.

Most sealants dry to quickly forcing you to work at a brisk speed. After just 2-3 minutes the thin edges of caulk will have dried and will be very difficult to smooth.

Most gaps will require one application and look great.

Large gaps, a ¼ inch or more, will require two applications before painting can take place. The reason for this is the caulking shrinks as it cures. Very wide gaps, ½ inch or wider, will need to be handled differently. A very wide gap needs to be pre-filled prior to applying any sealant. Use foam backer rod, available in various widths from ½ to over an inch.

Simply push the appropriate thickness of backer rod into the gap, choose a thickness slightly larger than the gap. Keep the backer rod just under the surface so the caulk won’t be too thick, a little more than a ¼ inch. Wait for the first application of caulking to dry before applying any more.

Work with small sections at a time. Filling gaps will go quickly and after a short time you will be caulking like a pro.

Where to Apply

Many gaps and cracks can be caulked. Providing a more pleasing finish.

Stained Trim – Here we fill the gap between a wall and stained oak base. Previous painters were very sloppy while cutting in with a brush and left very thick and heavy edges on the trim. Use a damp rag to remove any excessive caulk and give it a smooth appearance. A paintable clear caulking can also be used after the walls are painted to seal this gap.

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Click To Enlarge

Click To Enlarge

Painted Trim – Baseboards, door casing and windows need to be checked for gaps. Pay special attention to gaps where the trim meets a frame, door or window. Remove any obstructions, such as hinges or locking mechanisms, for a cleaner look.

Cracks in Walls – Small cracks in the wallboard can be filled, this is usually done with cracked corners. Caulking is good for small non-structural cracks. Large cracks will need the proper repair.