[C320-list] Broken Stanchion - countersinking

[Warren Updike]

I've read articles advising that deck holes be chamfered (countersunk) to
hold a quantity of sealant. 

When I last did my chain plates I chamfered the bolt holes. After applying
BoatLife Caulk and installing the cover plate and bolts, I installed the
nuts from below while holding the screws from turning and tightened the nuts
until the caulk began to squeeze out.  You want enough caulk to be squeezed
out to eliminate any trapped air.  After the caulk had set somewhat, I
snugged the nuts not moving the bolts.  That was several years ago and no
leaks, yet.

Warren & Pattie Updike
1994 C320 #62 "Warr De Mar"

-----Original Message-----
From: Pat Ireland [mailto:cherie320 at gmail.com] 
Sent: Monday, August 08, 2011 12:04 PM
To: C320-List at catalina320.com
Subject: Re: [C320-list] Broken Stanchion

There is a thread on one of the other forums that recommends a countersunk
hole to make room for caulk to seal around the bolt where it passes through
the deck.  The logic is that if you let the caulk set up and then tighten,
the bolt breaks the seal when you tighten it and the joint will fail.  Lots
of folks say they have had good luck with the setup and then tighten method,
so I'm not so sure about the premise.  It certainly took a long time for the
Life Caulk to fully set up when we used it.  The countersink does seem like
a good idea and may be an approach that makes a good seal in one step.
This same post recommended the butyl tape as a bedding compound because it
does not dry out.  You can use as much or as little as you require and store
it to be used again.   I have no experience with it, so your milage may
vary.  Thank you all for posting your info and experience.
Pat, 801