[C320-list] Rebeding Chain Plates

[Allan S Field]

>From my personal archives...

I had a problem with the middle stanchion on the port side.  The following
is plagiarized from this forum (be glad to give credit to the original
author...if I remembered who it was) :
 
1.. Move your cushions far away from the big mess you are about to make and
also get the table out of your way. Place some rags or an old towel under
the work area.
  2.. Remove the shroud.
  3.. Remove the strut. Remember the sequence and position of the spacer and
washers at the bottom of the strut. Mark the spacer so you know which side
is up. A crows-foot socket makes loosening (and tightening) the nuts on the
bottom of the strut a little easier. The strut holds a bit of tension
between the deck and the beam that is built into the liner. Notice how many
turns it takes before the upper nut on the bottom of the strut comes loose
and releases that tension. This will help when you reinstall and re-tension
the strut. Typically the nut will come loose after about 1 1/2 turns.
  4.. Remove the 4 Phillips head thru-bolts. The threads may be galled so
you might need to purchase new ones, 1/4 x 20 x 1.5".
  5.. Remove the tang (step on it).
  6.. Mask the deck around the trim plate so clean-up after caulking is a
little easier.
  7.. Pry the trim plate off of the deck.
  8.. The hole in the deck is larger than the tang and is filled with caulk.
Clean out all of the old caulk.
  9.. If the deck has a wooden core, clean out any rotten wood, let the core
dry and fill the void with an appropriate filler.
  10.. Clean the deck and cabin liner surfaces with a razor scraper, gasket
scraper, Dremel tool, wire brush or any other suitable tool, and wipe them
down with acetone.
  11.. Use a chamfering bit to lightly chamfer the screw holes and a file to
chamfer the larger hole.
  12.. Install the tang with the 4 screws but without the trim plate. You
don't need to use any caulk on the underside of the tang. If the topside is
sealed there doesn't seem to be any purpose to it. If the topside seal
breaks, the underside caulking might keep some water out of the boat, but it

might also mask the problem while your deck rots.
  13.. Fill the space around the tang with Boat Life's Life-Calk and let it
cure overnight. Life-Calk is available in caulk gun tubes which are easier
to use than the smaller squeeze tubes when filling a large area.
  14.. Trim the dried caulk around the tang so that it is flush with the
deck.
  15.. Remove the Phillips bolts.
  16.. Put a heavy bead of caulk around the tang.
  17.. Put some caulk in each bolt hole.
  18.. Put a bead of caulk on the deck around each bolt hole.
  19.. Carefully place the trim plate in position. Use a couple of bolts to
align it as you press it down firmly and force the caulk up between the
plate and the tang.
  20.. Put some caulk under the head of each bolt and push the bolts into
the holes while pulling up on the tang. Don't push the tang down and ruin
the seal.
  21.. Tighten the 4 bolts. It would help to have someone on hand to assist
with this step but it can be managed without assistance.
  22.. Clean up the caulk and remove the tape.
  23.. Attach the strut. Hand tighten the upper nut until snug, and then use
a wrench to tighten it approximately another 1 1/2 turns.
  24.. Attach the shroud.
*****************************************

For those to timid to attack a leaking chain plate, here is what I found.
The prepurchase survey reported moisture in the center chain plate port and
starboard. 

I removed the shrouds from the plate. There is simply no other way. Mark the
threads with tape then back off the adjuster counting the turns.  This will
make retensioning the shrouds easier.  Now, completely remove the plate from
the hull. Dig out all the old caulk to expose the cut edges of the deck.
Those of you who have water entering the salon will almost certainly have
water soaked balsa core in the deck.  

In later models of the 320, Catalina saw fit to make the deck solid
fiberglass where the chain plates pass through. This was not the case with
#26. The balsa core was so wet it crumbled without the support of the caulk.
There is no choice but to remove the soaked core, fill the void with epoxy
filler, and recaulk the entire opening.

One way is to bend a nail to create a 1/2" hook. Remove the head and put the
nail in a power drill.  Use this to remove as much of the balsa core as
possible.  Let the opening stand long enough to dry more of the core.  Use
hair dryer or other mechanical means.

When dry, mix epoxy with a slow cure hardner and lots of filler to make a
peanut butter paste.  (I recommend the West System product.) Next tape over
the deck opening from the inside. Now, with whatever tools you can muster,
force the putty into the space between the deck and liner taking great pains
to fill in a circular manner so as to force out as much air as possible. Let
fully cure. Then reassamble the chain plate with polysuflide caulk or
polysulfide/silicone product.  

Another method I've heard about is to again seal the opening from the inside
and complete fill the opening, the entire opening with an epoxy mix that
will flow.  When hard, simply drill out a new opening through the now solid
epoxy deck.  

Do not delay doing this another season. The rotting core will only get
worse.  It's not really that bad of a job.  If you don't count yoursefe
handy, do have a yard do the work.  Soft decks can make an otherwise clean
boat very hard to sell.
**************************
Jeff's instructions give some fine details and will solve some of the
problems I encountered. I'd add that I used a chamfering bit to bevel the
screw holes in the deck. I'm told this gives a better "pocket" of caulk
between the screw and deck. Chamfering is recommended with any screws
through the deck.

I used a pocket knife to loosen the caulk then pulled it out with pliers.
The excess old caulk on the deck I removed with a dremel tool and small wire
brush. Use care to only remove the caulk and not burn the gelcoat on the
deck not that appearance matters as this area should be under the plate.

Do not buy squeeze tubes of caulk. I use LifeCaulk by BoatLife. The stuff is
very stiff in the tube and squeezing it out to fill the void is difficult.
My store has tubes of LifeCaulk for use with a caulkiing gun. There are both
the normal long tubes and short tubes. A short tube is enough for both
center plates. Use a long tube if you are going to do all six. 

Doing it in two stages as Jeff instructs is the way to go. I did it in one
step and believe me, Jeff's way is easier. That is fill the space around the
tang to the deck, let it cure overnight, then do the plate and screws as
Jeff says.

Finally, my experts advise to not tighten the screws fully in assembling the
deck plate. Instead, just slightly more than hand-tight. Let it cure a day
or two this way to establish a layer of caulk. Then, when the screws are
tightened the caulk won't be squeezed out leaving to thin a bead under the
plate.

Now, if some enterprising person would organize the suggestions in this
thread, we'd have a nice technical piece for the 320 website.

***************************************
It is recommended to use the Woolsey Dolfinite Bedding Compound.  It does
not set up like others such as 3M 5200 or ooze as Silicon products.

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf
Of ROBERT MILLER
Sent: Friday, November 6, 2015 5:11 PM
To: c320-list at lists.catalina320.com
Subject: [C320-list] Rebeding Chain Plates

One of my chain plates has started leaking, and I'm looking for the best
procedure to re-seal them. I found reference to step by step instructions on
this job in the archives, but can't find the actual instructions in the
archives or in the articles on the 320 owners site. Does anyone have these
that they could share?
Thanks,
Rob Miller
Alchemy #571
Sidney BC

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