How to Seal Around Boat Port Lights

Eventually, a leaky port light will require a complete rebedding, a time-consuming and tricky project. It is difficult to get a watertight seal when rebedding a portlight, so if you're unsure of what you're doing, it may be worth having a professional show you how to do one properly. Then, you can do the others yourself. A temporary patch fix using silicone sealant, however, can reseal a port light for a few weeks or months, until you have time to address the problem more fully.

Things You'll Need

• Alcohol
• Clean rags
• Masking tape
• Silicone sealant
• Rounded putty-finishing tool

Instructions

1. Using a clean rag and rubbing alcohol, wipe the glass, frame edges and cabin side to remove any grease from the area that will be sealed or taped.

2. Apply a strip of masking tape on both the glass and the frame about 1/8 inch from the seal.

3. Squeeze a line of silicone sealant along the corner of the frame. Then use your fingernail or a rounded putty-finishing tool to press the sealant into a uniform concave profile.

4. After 45 minutes, remove the masking tape carefully so as not to tear the silicone.

Tips & Warnings

• Make sure not to use anything other than alcohol to clean your port lights. Other common degreasers, such as acetone, will damage plastic port lights.

References

• "Don Casey's Complete Illustrated Sailboat Maintenance Manual;" Casey and Compton; 2006
• "Sailboat Hull and Deck Repair;" Don Casey; 1996

Resources

• "How-To: The Don Casey Library": What Sealant Do You Need?