C&C 27 Association Forum

I did mine last year after a long battle with the old ones leaking the previous season.  I opted for plain old silicone after attempting 3M 5200.  The 5200 simply made a mess and made it impossible to get the holes on the under side of the rail lined up correctly.  I would use butyl tape if I did it again.  I just used some butyl tape to reseal my chain plate covers and simply pressed the cover in place and then screwed straight through the tape with no issues.

I have never had success with 5200 in my life and in my area of the world in the spring when we are doing this work it is often damp and cold and the stuff doesn't ever seem to set up.  I have since vowed that 3M 5200 or any of its counterparts, 4200 and the like, have no business on any boat of mine. If you can make a good mechanical fastening then I don't believe there is any worth in a fancy marine sealant like the 3M stuff.