In writes:

Many masts (at least by European makers) have the shrouds fixed to the
mast with some T-terminals in a "keyhole" in the mast. Inside the mast
there is a oval piece of stainless steel to support the mast profile,
the piece is fixed to the mast by a pair (sometimes three) pop rivets.
These plates bend slightly with the stress and pumping of the rig and
within some years they develope some hairline fractures.

I have lost a mast because of broken plate and I have changed these
plates (after learning the lesson) on a few boats of my friends. All the
plates I removed had some serious cracks in them.

So pay attention to the supporting plates inside the keyholes.

- Lauri Tarkkonen

Many SS chain plates holes are punched out of 1/4-3/8 thick bar stock. This
proactive is not all that good but tolerated.
It took 20 years for an hairline crack to show. The crack must have been
there all the time but not visible to the naked eye. The crack had it root
from the inside diameter of a 1/2 ID hole at about 3/4" from the top edge
of the plate. Having worked in a stamping shop before I realized that this
crack was made by punching a 1/2 hole too close to this edge with a heavy
press and a worn out punch and die.
I then took all the chain plates off. Went to the metal market and bought
some 316 SS bar stock. I cut them to length, rounded the corners and drill
the holes with the proper lubricant. Now I have new chain plates and I do
not to worry about the plates to give up in a big blow.



"Roger Long" wrote in message
. ..
Amazing how long it sometimes takes serious flaws to show up.

I went up to the boatyard today to take some sails from the boat to the
sailmaker and found that they had moved her into a slip from where I had
rafted alongside another vessel. When I stepped aboard, I saw the teak jib
sheet cleat broken off and lying on the cockpit seat. My annoyance at
clumsy line or boat handling changed to wonder when I picked up the cleat.
The countersinks for the bolt heads had been over-enthusiastically drilled
so deep that there was less than a quarter inch of teak holding the cleats
to the coamings. Either that or some long ago Florida boatyard worker was
making up for not having long enough bolts.

Between the bung at the top of the cleat and the bolt heads was over an
inch of air! The part of the cleat that takes the line strain was
completely unsupported by the metal bolts.

I’d thought about replacing these cleats because they sometimes get used
for mooring lines and are pretty critical to handling the big Genoa. They
looked nice however and I figured that they must be up to the job since
they had held up since 1980. Looking at the broken cleat though, I can’t
believe they lasted through the boat’s first week of sailing, let alone 26
years.

There will be a pair of new bronze cleats on the coamings next season.

--

Roger Long