[Public-List] Chainplates

Randy Katz via Public-List public-list at lists.alberg30.org
Tue Jan 26 21:28:24 PST 2016


Thanks, Wes. Yes, that makes perfect sense; I get it. I think you gave a
good explanation--good enough for me anyway.

Regards,
Randy
#249


On Tue, Jan 26, 2016 at 6:37 PM, Wes Gardner <wesgardner1952 at gmail.com>
wrote:

> My reply is this- I won't get into a right-way/wrong-way contest here and
> so I understand that each person is going to need to evaluate the shear
> strength of the bolts holding their chainplates in place. I believe the
> documented failure(s) are in truth, in shear. This is where the chainplate
> actually "cleaves" the bolt clean off in a guillotine-like fashion (can't
> think of a better way to explain shear).
>
> So here's the logic of placing bolts in the "correct" way - simply there's
> more "meat" at the shoulder end than at the threaded end. Are we good with
> that all you structural engineers?
>
> So it stands to reason that if you let the shoulder end of the bolt bear
> where the actual chainplate contacts said bolt, you'll have more metal
> there to withstand that shear force. Remember now, we're talkin' shear
> force here, not tensile force. Am I good with all my structural guys?
>
> Obviously, buy bolts that have as much shoulder as possible, without
> having too much.
>
> I'll leave it there....
>
> Wes
>
> > On Jan 26, 2016, at 12:40 PM, Jim Mennucci via Public-List <
> public-list at lists.alberg30.org> wrote:
> >
> > randy
> >
> > if you have washers the same size under the bolt head and the
> > nut...then they're structurally equivalent and bolt direction doesn't
> > matter.  Aesthetically bolt heads would look better in the main cabin.
> > More importantly, best for you to use 5/16 bolts with the correct grip
> > length i.e., insure that you have only the untlhreaded length of the bolt
> > in bearing--no threads in contact with the wood/glass.  When I did the
> > alberg many years ago, I used aluminum flat stock and transfer drilled
> the
> > 3 bolt holes.  This makes it more improbable that the bolts can pull thru
> > if the wood becomes soft and better distributes bearing loads from the
> > bolts--it's hitting a finish nail with a sledge hammer but is the best of
> > all.
> >
> > Jim Mennucci
> >
> > On Wed, Nov 4, 2015 at 6:05 PM, Randy Katz via Public-List <
> > public-list at lists.alberg30.org> wrote:
> >
> >> Hi,
> >> Yes, I've heard that 5/16 is the way to go. I also understand that
> >> alternating the directions of the bolts is the way to go--like this: top
> >> bolt, head sticking out; second bolt, nut end sticking out; third bolt,
> >> head sticking out.
> >>
> >> Who knows?
> >>
> >> Randy Katz
> >> #249 Simple Gifts
> >> Seattle/Bellingham, WA
> >>
> >>
> >>
> >>> Message: 3
> >>> Date: Tue, 3 Nov 2015 23:02:35 -0500
> >>> From: Wes Gardner via Public-List <public-list at lists.alberg30.org>
> >>> To: Glenn Brooks <brooks.glenn at comcast.net>
> >>> Cc: Alberg 30 Public List -- open to all
> >>>        <public-list at lists.alberg30.org>
> >>> Subject: Re: [Public-List] chainplates
> >>> Message-ID: <C41E5648-59D2-4DE2-AF93-7E968758928C at gmail.com>
> >>> Content-Type: text/plain;       charset=us-ascii
> >>>
> >>> Hey All,
> >>>
> >>> Did I also mention that someone did in truth "upgrade" to 1/4" shoulder
> >>> bolts but then proceeded to run the bolt in "backwards" such that the
> >>> chainplate still bore on the nut end and therefore the threaded portion
> >> of
> >>> the shoulder bolt, in effect doing absolutely nothing.
> >>>
> >>> Make sure your bolts are in the "right" way....
> >>>
> >>> I assume most folks have upgraded to 5/16"????
> >>>
> >>> Wes
> >>>
> >>>> On Nov 3, 2015, at 9:01 PM, Glenn Brooks <brooks.glenn at comcast.net>
> >>> wrote:
> >>>>
> >>>> Wes,  no reason to bond the chain plate.  Far better to reinforce the
> >>> knee for the forward lower chainplates with several additional layers
> of
> >>> fiberglass mat and roving, then drill, bed and reinstall the
> chainplates
> >>> with 5/16" bolts.  I actually anchored all my upper chainplates with
> one
> >>> 3/8" bolt, and then added 5/16" bolts.  The biggest risk after
> >> reinstalling
> >>> the chainplates with larger bolts is that the knee might pull away from
> >> the
> >>> hull. Hence the preventative measure of adding DG reinforcement.
> >>>>
> >>>> It's perfectly fine, actually necessary, to bed the thru deck area
> >> where
> >>> the chain plates emerge from the deck, with 4200 or 5200. The material
> >>> flexes a bit and keeps out water- preventing rot and delamination in
> the
> >>> knees and bulkheads.
> >>>>
> >>>> Glenn B.
> >>>>
> >>>> Sent from my iPad
> >>>>
> >>>>> On Nov 3, 2015, at 5:44 PM, Wes Gardner via Public-List <
> >>> public-list at lists.alberg30.org> wrote:
> >>>>>
> >>>>> Yes, at first I was considering bonding the chain plate to either the
> >>> knee or bulkhead but I think maybe the crevice corrosion factor may
> >> prevent
> >>> that.
> >>>>>
> >>>>> Sent from my iPhone
> >>>>>
> >>>>>> On Nov 3, 2015, at 7:10 PM, Randy Katz via Public-List <
> >>> public-list at lists.alberg30.org> wrote:
> >>>>>>
> >>>>>> Greetings,
> >>>>>>
> >>>>>> Was it Wes talking about replacing bolts and gooping over with 5200?
> >>> If I
> >>>>>> understand the comment correctly, I'd suggest using something other
> >>> than
> >>>>>> 5200 so access to the bolts could easily be had at a later date.
> >> Also,
> >>>>>> leaving the SS hardware open to the air as much as possible can
> >> reduce
> >>>>>> possibilities of crevice  corrosion.
> >>>>>>
> >>>>>> My apologies if I misunderstood the post!
> >>>>>>
> >>>>>> Regards,
> >>>>>>
> >>>>>> Randy Katz
> >>>>>> #249 Simple Gifts
> >>>>>> Bellingham/Seattle WA
>



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