Cathe, as far as clearance markers and trim lamps, always seal behind the fixture itself; between the fixture base and the side or cap on the RV. Butyl caulk is commonly used for this, but I recommend Eternabond double-stick tape. It simply is not prone to drying out and cracking over time like some butyl caulks or putty tapes. Do NOT seal the lens itself to the fixture. Many clearance lamp lenses are simply snapped into place (others are secured with screws), and all must have some method of disassembly in the likely event a bulb will eventually burn out and require replacing. Your “hammer” reference withstanding! You may even want to upgrade and switch to LED lamps. Tuesday, December 13, 2011
Sealing RV Clearance Lamps
I bought a 27-foot Minnie Winnie back in 1992 and have maintained it quite well. I have been able to repair all of the run/clearance light issues and I'm now ready to re-caulk them to keep the water out. I have your book and have cruised your website and the Internet but have not found specific instructions. Should I caulk all around the fixture base and then add some caulk all around the lens before putting it back on the base fixture? I recently had to take a hammer to one of my lenses that I had caulked a few years ago to get it off and it wasn't easy to find an exact replacement lens. Also, want to thank you for your You Tube video on adjusting the RV water heater flame. It helped me understand how my water heater really worked. Before I saw your video, I had replaced the electrode assembly because I thought the main burner wasn't lighting, but it was. So I cleaned the air adjustment tube, put on a new electrode assembly and still no hot water. It was driving me crazy so I reviewed more of your info and finally figured out the problem - it was one of my water heater bypass valves in the wrong position! Thanks for all the help! Cathe R., (West Springfield, MA)
Cathe, as far as clearance markers and trim lamps, always seal behind the fixture itself; between the fixture base and the side or cap on the RV. Butyl caulk is commonly used for this, but I recommend Eternabond double-stick tape. It simply is not prone to drying out and cracking over time like some butyl caulks or putty tapes. Do NOT seal the lens itself to the fixture. Many clearance lamp lenses are simply snapped into place (others are secured with screws), and all must have some method of disassembly in the likely event a bulb will eventually burn out and require replacing. Your “hammer” reference withstanding! You may even want to upgrade and switch to LED lamps.
Great follow-through on the water heater issue! I’m happy to hear the information was helpful.
Cathe, as far as clearance markers and trim lamps, always seal behind the fixture itself; between the fixture base and the side or cap on the RV. Butyl caulk is commonly used for this, but I recommend Eternabond double-stick tape. It simply is not prone to drying out and cracking over time like some butyl caulks or putty tapes. Do NOT seal the lens itself to the fixture. Many clearance lamp lenses are simply snapped into place (others are secured with screws), and all must have some method of disassembly in the likely event a bulb will eventually burn out and require replacing. Your “hammer” reference withstanding! You may even want to upgrade and switch to LED lamps. 
