Proper Silicone Caulking on Glass Doors

Use rubbing alcohol to remove any dirt or debris from the seams of the glass door, wiping away moisture with a clean cloth. Take two passes over the seams to ensure they're clean, as oils and dust can interfere with the caulk's adhesion.

Line the seam of the door with masking tape applied directly to the glass. Keep the masking tape in a straight line; this ensures you don't make a messy seam with the caulk. Apply a second strip of masking tape to the glass door’s frame. The masking tape should evenly line the door's seam, exposing only the area to which you plan to apply the caulk.

Load the tube of weatherproof silicone caulk into a caulking gun, per the manufacturer’s instructions. The gun should not apply any pressure to the caulking tube at this time.

Hold the caulking tube over a trash can to catch any silicone that might drip out. Cut the tip off the tube at a 45-degree angle, about 1/4 inch down the tube. Slice at the marked score line, if one is available. The angled cut helps the silicone caulk go on the glass door smoothly.

Squeeze the caulking gun’s trigger until caulk flows from the tip of the tube, into the trash can. Stop squeezing the trigger, or release the trigger lock if there is one present on the gun.

Place the tip of the silicone caulking tube against the seam of the door, starting at a corner. Lift the gun slightly above the seam with the angled hole positioned over the space between the masking tape strips.

Apply pressure to the caulking gun’s trigger; as soon as caulk begins flowing from the tip, begin slowly moving along the seam. Keep the tip a consistent length away from the seam for an even application. When you reach the end of the seam, stop applying pressure and set the gun aside.

Place the tip of the curved putty knife against the caulked seam, at the corner where you began. Scrape it along the seam gently, smoothing the rounded surface of the caulking bead. Repeat the application and smoothing process with the remaining interior and exterior seams of the glass door.

Allow the caulk to dry for the time specified by the manufacturer and carefully remove the masking tape. The result should be a professional-looking caulk line.