[Public-list] Chainplate covers?
Mike Lehman
sail_505 at hotmail.com
Wed Dec 15 09:10:02 PST 2004
Stiff is not good. It will crack. Squishy stuff (like 5200) is good because
it moves with the boat. There is a tremendous amount of lifting and twisting
forces on the hull/deck/chainplates/bulkheads that are constantly changing.
If you have spent time on these boats in heavy weather you would have a
greater appreciation for the amount of stress that is imparted of these
vessels. As an example, I cite the stringers on the inside of the hull that
the pegboard is attached to on the newer style boats. The stringers were
attached with resin and it was hard. When I removed the pedboard, every
stringer had broken free from the hull because it was a hard spot that would
not flex. I re-attched the stringers with 5200 and it has been 17 years
without breaking, because they flex.Your chainplate design looks
interesting, I have never seen anything like that on any other boat before
except on smaller daysailors. All of the larger boats that I have seen, 40+
feet use a design similar to that of the A30, only with bigger parts and
more bolts. None that I have seen connect the deck-bulkhead-chainplate, as
your design proposes. All pass thru the deck and connect directly to the
bulkhead, as is done on the A30. Good luck with that design, let us know how
it works in heavy weather.
Mike Lehman
><((((º>¸.·´¯`·...¸><((((º>
----Original Message Follows----
From: "Roger L Kingsland" <rkingsland101 at ksba.com>
Reply-To: Alberg 30 Public List -- open to all <public-list at alberg30.org>
To: "Alberg 30 Public List -- open to all" <public-list at alberg30.org>
Subject: Re: [Public-list] Chainplate covers?
Date: Wed, 15 Dec 2004 10:49:46 -0500
There seems to be an inherent problem with any detail where the chainplate
passes through an "open" hole in the deck that must be filled with sealant.
At best it is a critical maintenance issue; at worst, a means for water to
degrade structural bulkheads. The chain plate must be flexible to the point
where it first fastens to the bulkhead which is the top bolt. At that point
it must be completely rigid or the chainplate will move and eventually
loosen. Why not move that "point of rigidity" up so it is above the deck
and a flexible connection through the deck is unnecessary?
As part of the redo of the deck on #148, I have removed the chain plates and
filled in the holes. One solution I thought about for the reinstall was to
make 1/4" SS deck plates (roughly 2" x 3") with the a short piece of
1/4" welded vertically on the center to fasten the bottom of the turnbuckle
(basically cutting off the top of the cahinplate and welding it onto the
deck plate). Then make "L" shaped brackets to mount on either side of the
bulkhead with the short leg of the "L" mounted against the underside of the
hull to deck joint (one of the stronger areas of the boat). Vertical holes
in the short leg drilled near the 90 degree bend would align
with holes in the deck plate and two bolts through the deck would carry the
load from the deck to the chainplates bolted to the bulkhead. All plates
would be set in a 1/16" resin bed and bolts would be tightened sufficiently
to get that good old friction connection (none of that squishy 5200 stuff).
It seems this solution would be strong, stiff, dry and fairly easy to
install. I have posted a sketch on
http://home.att.net/~jinnii/roger/perfect/pi_designs.html
and would appreciate any feedback.
Thanks,
Roger Kingsland
----- Original Message -----
From: "Alfredo" <alberg30sail497 at yahoo.com>
To: "Alberg 30 Public List -- open to all" <public-list at alberg30.org>;
<dk.campbell at sympatico.ca>
Sent: Monday, December 13, 2004 3:29 PM
Subject: RE: [Public-list] Chainplate covers?
> Since we're on the topic, this is how I intend to someday do the
> chainplates on Free Spirit.
>
> http://www.gizmology.com/V40/Upgrades/chainplateFix/index.html
>
>
> --- "sousa, stephen (ENG)" <sousa_stephen at emc.com> wrote:
>
> > Don,
> >
> > If you could share the method used for the pattern it would be
> > appreciated.
> > This may be one of those items that would fall into the group
> > purchase area.
> > It would benefit all Alberg owners and could be very inexpensive it
> > we
> > purchase a large quantity. I would expect that all boats have the
> > same
> > installation for chainplates, so one pattern could be used on all
> > boats?
> >
> > Thanks,
> > Stephen
> >
> >
> > -----Original Message-----
> > From: public-list-bounces at alberg30.org
> > [mailto:public-list-bounces at alberg30.org] On Behalf Of Don Campbell
> > Sent: Sunday, December 12, 2004 7:48 PM
> > To: Alberg 30 Public List -- open to all
> > Subject: Re: [Public-list] Chainplate covers?
> >
> > Randy
> > When I bought #528, I was taken to see a C & C deck which had a
> > raised
> > flat area around the chainplates with the SS plates of which you
> > speak. I
> > knew I needed to redo the deck on this boat so incorporated a raised
> > flat
> > area at the chainplates on my new deck. I then went to the scrap yard
> > and
> > found some 1/8th stainless plate that was food grade so probably 316
> > (which
> > is probaly not what is best for a marine environement, 304 is
> > stronger and
> > more durable, I gather, but strength is not that important here),
> > cut it to
> > size- about 1 1/2" x 2 1/2" and then took it to a machine shop to
> > have the
> > slot cut. I needed to file the edges a bit to get the chainplate
> > angle
> > correct in the slot but SS is relatively soft, so not difficult once
> > in a
> > vise. I have drilled 2 holes in the plates and drilled and tapped the
> > epoxy,
> > raised flat areas to match so I just tighten the 2 - 1/4 x 1/2 ss
> > machine
> > bolts to seal the caulking. Total cost about $25 Canadian when I did
> > it 8
> > years ago -$20 of that for the machinist. I need to redo that
> > caulking job
> > this winter. The raised part of the deck decreased the torque and
> > twist on
> > the chainpates at the deck level too. If you want to know how I did
> > the
> > pattern for the raised flat area let me know.
> > Don
> >
> > Randy Katz wrote:
> >
> > > Speaking of chainplates (nice photos of the reinforcement straps,
> > BTW)
> > > has anyone found a source for chainplate covers? They are the oval
> > SS
> > > plates 2-2.5 inches long, slot in the middle, that fit over the
> > > chainplate straps where they stick out of the deck. They get
> > caulked and
> > > sit over the deck opening, with the chain plate strap coming up
> > through
> > > their middle, and serve to help seal that deck opening.
> > > I've checked West Marine and a few other stores-- they seem hard to
> > find
> > > at all but ones the size we need I never did come across.
> > > Anyone know where to get them?
> > >
> > > Many Thanks,
> > > Randy Katz
> > > #249
> > > Seattle, WA.
> > >
> > > _______________________________________________
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