Sealant to use where the shrouds go though the deck?

[srah1953]

What is the best type of sealant to use where the shrouds go though the deck? There is a degree of moving and flexing. I've tried sikaflex but it comes undone.
Many thanks

 

[TradewindSailor]

Make sure that there is enough space around the chainplate ... say 5mm .... and caulk with a good marine silicone like 3M's. If the caulk seam is not wide enough .... usually 3x the expected maximum amount of movement the caulking will either rip itself apart .... or more usually become detached from one side ( when not stressed, nothing looks wrong with the seam)

 

[BlackPig]

I had this problem and was advised to put wooden blocks on the deck to raise the problem area. I have done this and it seems to work.

 

[vyv_cox]

I try not to use silicone sealant for anything on board. It has poor mechanical strength and poor adhesion unless a primer is used. I do not have a problem with Sikaflex 291 but the design of chain plate on my boat may well be different from normal. The hybrid sealants like CT10, Sticks like s**t and others have good adhesion and high elasticity, so may well be just what you are looking for.