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How To Choose and Use Caulk - Part 2

Putting Caulk To Work - Cont'd.

  • Your finger is the best tool to smooth the caulk into a perfect bead. Keep the finger that you use moist, even if using a caulk that is not water based. Wipe off excess caulk on a rag and do not try to save a few cents, by reusing excess caulk that has been removed. It is most likely contaminated with dirt or other foreign substances.
  • Unless you have entered some obscure caulk contest, do not attempt to create the perfect bead. The more you try to smooth out the bead the more likely you are to ruin a bead that was quite acceptable.

Place tube in a caulk gun as shown in Figure 1; pull trigger several times to tighten plunger against the inner base of the tube.

Cut the end of the caulk tube nozzle at a 45 degree angle, as shown in Figure 2. A 3/8 inch opening is the right size for most projects. Use a nail or awl to puncture the seal in the top of the tube.

inserting caulk tube in caulking gun
Figure 1 - Loading a caulk gun
cutting end of caulking tube
Figure 2 - Cutting a caulk tube nozzle

Place the nozzle against the seam, as shown in Figure 3. Angle the gun at a 45 degree angle in the direction it will travel. Squeeze trigger gently for even flow.

To ensure a neat finish and firm contact on either side of the seam, smooth fresh caulk with a stick, suitable tool or your finger, as shown in Figure 4.

applying caulking
Figure 3 - Placing the caulk tube nozzle against seam
smoothing caulking
Figure 4 - Smoothing applied caulk

There is no consensus on whether you should push the caulk forward or have the caulk trail behind the caulk tube tip. Personally, I do both, depending on the circumstances. Whatever method works best for you is the correct method. The most important point, is to ensure that the caulk is filling the crack as it is being applied so that a sound seal between the edges will be formed.

This is called laying a bead and the correct and incorrect finished beads are shown in Figure 5.

Correct and Incorrect method of laying a bead of caulking
Figure 5 - Correct and Incorrect method of laying a bead of caulk

The tip of the caulk tube should be cut at a 45 degree angle and must be smooth. If you have rough edges on the inside of the applicator tip the caulking will not run smoothly. Use a knife to remove any rough edges on both the inside and outside of the tip. The hole should be about 1/8 of an inch in diameter. It should always be smaller than the crack you are trying to fill. Hold the tube or caulk gun at a 45 degree angle so that the tip straddles the joint. Squeeze the trigger on the gun or squeeze the outside of the tube, as the case maybe, to start the caulk to flow. Once the caulk is flowing, keep a consistent pressure on the trigger or tube. Move the tube at a steady speed over the crack and allow the caulk to fill the void.

A new innovation in applying caulking is the electrically powered caulk gun, as shown in Figure 6. The powered gun ensures that a constant pressure is applied to release the caulk and saves crippling your hand if you have a lot of caulk to do.

electric caulking gun
Figure 6 - Powered caulk gun

Additional information on powered caulking guns.

If the surface texture of one or both sides of the joint have a texture, it will be more difficult to create the perfect bead. The important point is that the caulk adheres to the textured surface without any gaps. Running your finger over the surface of the caulk will usually accomplish this.

Water is heavy:

If you are applying caulk around bathtubs, or sinks, fill them with water before you apply the caulk. Water is heavy and in most cases the bathtub or sink will be lower when filled. Caulk works better in compression, hence if the bathtub or sink is caulked in its lowest position it will be sealed when filled and when empty. If it is sealed when empty, it is possible that the caulk will pull away from one of the objects when filled.

Caulk Chart