Originally Posted by JEM
New around here, doing a couple things sleepable but not Sportsmobiles.
I'm not confident of silicone sealant sticking to metal over time, or its resistance to solar UV.
For something like this the UV-resistant 3M marine sealant (4200UV?) might be a better option. The 5200 may be a stronger adhesive (I love that stuff so much, it's Curse Of The Pharoahs strong, it's hell even to scrape off a porcelain toilet) but not sold as UV-resistant.
I made that fix years ago and so far, so good. That said, we don't get much rain here in Southern California to test it. But the adhesive isn't exposed to the sun because the plug has a lip on the top to shade the glue. Besides, that's what I had on hand that isn't too messy.