5200 worked fro me in that application
There are at least 100 sealants, puttys, caulks and adhesives that would work to keep water out in this application. When looking for one of them, keep these things in mind:1. Will it seal in the application I am using it for?2. Does it need adhesion qualities or just water barrier qualities?3. Do I need to remove it in the future?4. Does it show when the job is done or is it hidden?5. How much time do I have to work with it before it cures, sets or hardens?6. What consistency does it need to be for where I am putting it....... ie. will it run down the side of the boat if I use it?7. Will it be affected by UV, temperature or pressure?These are a few things to think about when using sealant materials. I am no expert, but there is more to consider than just keeping water out.3M 5200 marine caulk has worked good for me on the same handrails. I used very little around the screw holes and tightened them. 5200 doesn't come off easily, so I wouldn't use it if you want to refinish often. Another option is marine putty.... sorry I don't have part numbers. The putty stay plyab;e but is not very sticky. It works more like a gasket.Good luckWard