Applying Caulking

Applying Caulk

Although not a high-tech operation, caulking can be tricky. Read and follow the instructions on the compound cartridge, and remember these tips:

For good adhesion, clean all areas to be caulked. Remove any old caulk and paint, using a putty knife, large screwdriver, stiff brush, or special solvent. Make sure the area is dry so you don't seal in moisture.

Check the gap for size!  If it is too big use a flexible foam backer rod to fill the gap before you apply the caulking.  Push the rod into the gap about an eighth of an inch.

Apply caulk to all joints in a window frame and the joint between the frame and the wall.

Hold the gun at a consistent angle. Forty-five degrees is best for getting deep into the crack. You know you've got the right angle when the caulk is immediately forced into the crack as it comes out of the tube.

Caulk in one straight continuous stream, if possible. Avoid stops and starts.

Send caulk to the bottom of an opening to avoid bubbles.

Make sure the caulk sticks to both sides of a crack or seam.

Release the trigger before pulling the gun away to avoid applying too much caulking compound. A caulking gun with an automatic release makes this much easier.

If caulk oozes out of a crack, use a putty knife to push it back in.

Don't skimp. If the caulk shrinks, reapply it to form a smooth bead that will seal the crack completely.

The best time to apply caulk is during dry weather when the outdoor temperature is above 45°F (7.2°C). Low humidity is important during application to prevent cracks from swelling with moisture. Warm temperatures are also necessary so the caulk will set properly and adhere to the surfaces.