[C38] Backstay chainplate bulkhead

[Phil Gay]

Tom,

 

I'm glad to hear that the repair has held up.  How did you have access to
the knee to apply the glass cloth around it without removing the chainplate
welded assembly?  I don't believe that you can get the chainplate back into
position sandwiching the knee once the knee is in place without cutting into
the deck.  Note to Listserve readers:  you almost have to see how this fits
to totally understand.  Photo attached.

 

Phil Gay

C38 049 Que Linda

Everett, WA

 

From: listserve-bounces at catalina38.org
[mailto:listserve-bounces at catalina38.org] On Behalf Of Tom T.
Sent: Monday, March 31, 2008 10:32 AM
To: Catalina 38 Listserve
Subject: Re: [C38] Backstay chainplate bulkhead

 

Hi Phil,

 

The back stay knee is a weak link on the Catalina as several of us have
found out.  Any water leaking down the back stay will eventually saturate
the laminated wood inside the knee allowing it to rot.  The knee looks like
2" of solid fiberglass but is actually a piece of laminated wood bonded to
the hull and transom.  When I removed the back stay chainplate, I was able
to poke a screwdriver in the holes and the wood in the middle of my knee was
pure mush.

 

I cut off most of the port side of the knee allowing easy cleaning leaving
only the starboard side of the laminated fiberglass left.  I then used a
meatloaf pan to lay up a "brick" of fiberglass to a thickness of about 1
1/2" as a plug to replace the missing wood.  I then bedded this plug where
the old wood had been using clamps and long strand bedding putty.

 

Once the new insert was bonded and cured in place, I used more bedding
material to finish off the seams etc until the new "brick" looked smooth and
fair.  Use some bedding material to fillet the corners where the knee meets
the hull and transom.

 

Finally I put many layers of fiberglass cloth over the exposed port allowing
the glass to wrap around the corners to bond to the hull and transom.  This
is a time consuming process but by using many layers of lightweight cloth, I
was able to make the corner transitions without voids.  Carefully keep
checking the thickness of the new knee between lay ups so the chainplate
will fit properly when you remount it.

 

By squeezing out the excess resin on each lay up, the glass to resin ratio
will be very high making a very strong repair.

 

Once the project is finished, a layer of white paint and it will look
exactly like the original but  much stronger and rot proof.

 

Nothing could ruin your cruise worse than being on a high wind spinnaker run
and seeing your standing rigging and sails try to outrun your boat when that
old back stay knee failed.

 

I fixed my back stay knee in 2002 and it has looked perfect ever since.   I
think I could now pick up my boat by the back stay chainplate but I'd rather
it be overly strong than chance failure.

 

Tom T.

Renata, hull 95

St. Pete, FL

 

 

 

 

----- Original Message ----- 

From: Phil Gay <mailto:eyriepg at comcast.net>  

To: Listserve at catalina38.org

Sent: 3/31/2008 12:09:57 PM 

Subject: [C38] Backstay chainplate bulkhead

 

While this is addressed to the Listserve, the question is specifically
addressed to "the man with the plan," our own tech tips editor, Tom T:

 

A couple of years ago, I noticed that the fore-aft bulkhead which the back
stay chainplate is attached to was rotten.  As a short term fix, I added
stainless steel straps on each side of the chainplate fitting that
transferred the load down lower into the bulkhead and picked up the
fiberglass tabbing of the bulkhead to the hull.  This seemed to arrest the
forces pulling up on the deck.  Now is the time to go to another chainplate
configuration or replace that rotten bulkhead.  I remember that you, Tom,
did a little more thorough job of fixing the problem by replacing the
bulkhead.  Could you detail the fix and tell me how good it has been in the
long term.

 

Phil Gay

C38 049 Que Linda

Everett, WA

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