Jere Lull wrote:
33 years after being laid, our hull's original gelcoat glowed this
spring when I polished it.

Well, sure.


Topsides is a little rough as we have some non-structural delamination
that I haven't finished fixing and the previous owner's paint died. I'd
rather sail than work.


For us, seems to come & go in cycles... right now we're in a work cycle,
an apparently endless loop of projects which lead to the boat getting
better & better, eventually one of us gets fed up and says 'Let's go for
a boat ride today.'



The big problem was that I allowed the main bulkhead to rot. Cost me
about US$300 in materials and a couple of weekends' work. Should last
another thirty or so years.


You mean the bulkhead(s) under the chainplates? Not uncommon... try
replacing the aft station bulkhead. Maybe your boat is laid out such
that you don't have to tear out too much of the cabin, which is good.

I've helped replace partial bulkheads under mast steps & chainplates,
usually that's not too big a job.

One of the boats that I know of, on which the owner is replacing the
bulkhead(s), the boat had to be placed in a specially built cradle and
about 90% of the interior removed. I'm not sure he's finished yet, in fact.


I see no reason to believe that she won't outlast me, and a sistership
that was better-maintained most of her life looks even better.


Looks ain't everything

One of the good things about fiberglass is that it has a very high
load-cycle life... in other words, it doesn't weaken with fatigue the
same way that metal does. If stressed to the point of flexing, even a
little bit, it does fatigue, but can go many many times more than metal.
One of the reason why it's said 'fiberglass is forever.'

Fresh Breezes- Doug King

Hey Guys,

Speaking of delamination and repairs, I'd appreciate your advice on
how to proceed on some repairs to my 1979 Catalina 27.

The standing rigging on the boat consists of three stainless cables
on each side, with the middle cable attached to the center bulkhead
and running over a single spreader to the top of the mast. The fore
and aft cables run from an aluminum plate at the bottom of the spreader
to the deck. This is just the rig that keeps the mast from moving side
to side of course.

The problem is that the deck around the aft cables is losing its strength
due to a delamination occuring underneath the side window. The deck is
still very sound to walk on, but no longer has the strength to take the
large tension loads from the rigging. The problem is only with the aft
cables.

We have been sailing the boat this way for years. When you are well
heeled over, the aft cable on the weather side of the boat will be tight, and
the other side will be loose, showing that the deck is giving by 1/2" or
so.

It seems to me that the rigging would be better attached to the hull,
instead of to the deck, and I've seen boats that were built that way.

The boat needs the deck re-gelled, or re-painted anyway, so I could route
out panels around the soft part and relaminate those areas before finishing.
There is a little problem with no-skid pattern in the area of the repair.

Another approach that I've considered is to custom fabricate four stainless
steel plates to throughbolt on either side of the hull. The inner plate
on each side would have an eye for connecting the standing rigging. I would
then run a turnbuckle from the backing plate on the bottom of the deck to
the eye on the inside stainless plate, and tension it such that the deck did
not have any load from the rigging. This would be much stronger
than the original design, although it does also provide a potential leak
source when the boat is heeled way over.

It seems that the deck is strong enough that with the water ingress stopped
(which it is), and the loading removed it would be serviceable for a long time.

What do you think?

Don W.



DSK wrote:
Jere Lull wrote:
Topsides is a little rough as we have some non-structural delamination
that I haven't finished fixing and the previous owner's paint died.
I'd rather sail than work.


For us, seems to come & go in cycles... right now we're in a work cycle,
an apparently endless loop of projects which lead to the boat getting
better & better, eventually one of us gets fed up and says 'Let's go for
a boat ride today.'

The big problem was that I allowed the main bulkhead to rot. Cost me
about US$300 in materials and a couple of weekends' work. Should last
another thirty or so years.


You mean the bulkhead(s) under the chainplates? Not uncommon... try
replacing the aft station bulkhead. Maybe your boat is laid out such
that you don't have to tear out too much of the cabin, which is good.

I've helped replace partial bulkheads under mast steps & chainplates,
usually that's not too big a job.

In article ,
Don W wrote:

Speaking of delamination and repairs, I'd appreciate your advice on
how to proceed on some repairs to my 1979 Catalina 27.

snip of a fairly standard rig
The problem is that the deck around the aft cables is losing its
strength due to a delamination occuring underneath the side window.
The deck is still very sound to walk on, but no longer has the
strength to take the large tension loads from the rigging. The
problem is only with the aft cables.

WHOA! I wouldn't diagnose that one long distance, though I believe I
know what you're saying.

Get a surveyor or, better, naval engineer to take a careful look and
recommend the method. Perhaps (probably?) he'll recommend a change to
the rigging and attachments.

Our surveyor (also a NA) told us how to do ours, and how serious it was
("maybe next year, perhaps" In other words, not an issue unless I saw
certain indicators). One factor is that very little load is carried by
our deck; it's almost all carried internally.

I don't believe yours is trivial. Frankly, I think you've been lucky.

The area can be stressed to several tons under certain conditions. Doing
it right will probably be a once in a lifetime fix if you correct the
original error(s). Doing it wrong could lose you a rig at exactly the
wrong time.

[is there a good time to lose the rig?]

--
Jere Lull
Xan-a-Deux ('73 Tanzer 28 #4 out of Tolchester, MD)
Xan's Pages: http://members.dca.net/jerelull/X-Main.html
Our BVI FAQs (290+ pics) http://homepage.mac.com/jerelull/BVI/

Jere Lull wrote:

WHOA! I wouldn't diagnose that one long distance, though I believe I
know what you're saying.

Get a surveyor or, better, naval engineer to take a careful look and
recommend the method. Perhaps (probably?) he'll recommend a change to
the rigging and attachments.

Our surveyor (also a NA) told us how to do ours, and how serious it was
("maybe next year, perhaps" In other words, not an issue unless I saw
certain indicators). One factor is that very little load is carried by
our deck; it's almost all carried internally.

It may be problematic to find a good surveyor in Austin TX since it is
so far from the ocean. We do have a fairly active yacht club so I'll
ask around. I'm a licensed engineer, and I do have a good feeling for
the loading. IMHO, the catalina rig design is weak in this area from the
factory. Thats why I suspect that the best fix is to take the load down
to the hull, and relieve the deck. I agree that it would be good to have
and experienced surveyor or naval engineer scope it out as well.

I don't believe yours is trivial. Frankly, I think you've been lucky.

So far, so good ;-)

The area can be stressed to several tons under certain conditions. Doing
it right will probably be a once in a lifetime fix if you correct the
original error(s). Doing it wrong could lose you a rig at exactly the
wrong time.

Yep. We plan on selling her eventually and moving to a larger blue water
capable boat, but I don't want to pass the problem on to the next suc... uh
owner.

[is there a good time to lose the rig?]

No. Only worse times ;-)

Thanks for your input Jere,

Don W.