Just saw a 737's landing gear after switching from the old sealant to that new polyurethane stuff, the difference after a year is crazy. | Aircraft Mechanics - Vivisector
My uncle had an old Ford with a spray-in liner that looked new after 10 years, and I honestly thought he was just lucky. But this sealant thing you're talking about is making me rethink that. @the_robert 's comment about the bathroom caulk is exactly how I used to feel about every product like this, always needing to be redone. Now I'm starting to think some things are just built different from the start, and it's not just random luck.