[Public-List] foredeck compression

Tue Jan 18 13:43:02 PST 2011

What will be your booth at the Halifax boat show
Richard 609

On Tue, Jan 18, 2011 at 4:34 PM, Gordon Laco <mainstay at csolve.net> wrote:

> HI Roger -
>
> I'm decompressing after the Toronto Show and gearing up for the Halifax one
> in a few weeks....
>
> With regard to your deck situation - you are on the right track with regard
> to examining reasons to bolster the laminate around the bolt holes with
> epoxy.  Yes, the column of solid goop will help somewhat but the main
> reason
> for the process is to make an dam around the bolts so that water can't get
> at the soft core.  Be it balsa or masonite, moisture will cause a sharp
> decline in its ability to cope with compression.
>
> Now I'm going to read the jokes....
>
> Gord
>
>
>
>
>
> On 18/01/11 3:06 PM, "Roger L. Kingsland" <r.kingsland at ksba.com> wrote:
>
> > Albergers,
> >
> > I have read recommendations that, for high load deck hardware like
> cleats,
> > one should remove the inner part of the deck around the bolt holes and
> fill
> > with epoxy to improve the compressive strength of the deck.  I was
> curious
> > if this approach was appropriate for an A30.
> >
> > I asked a materials testing guy I work with to test a 4" round section of
> > good old 148's foredeck (3 layers of FG and 2 of Masonite, no moisture)
> and
> > it failed at 20,000 pounds per square inch.  It actually slipped in the
> > press causing failure at the edge.  I suspect, had it been centered in
> the
> > press and failed uniformly, the pressure would have been much higher.
>  The
> > Masonite failed, not the fiberglass.  He also tested a piece of 1/2"
> plywood
> > which compressed to about half its thickness under the same load (with
> lots
> > of water squirting out in the process).
> >
> > I looked up the clamp load (75% of yield strength) of a 3/8", 316, fine
> > thread, SS bolt; it is 5,700 pounds (18-8 grade and course threads are
> > less).  Assuming a big bow cleat needing 2-3/8" bolts at each end and a
> 50%
> > safety factor, the area of each base of the cleat (less bolt hole areas)
> > would need to be 0.85 square inches or greater to prevent the bolt from
> > collapsing the deck.
> >
> > My conclusion (I am not an engineer but I sure like hanging out with
> them,
> > see Sidebar below to learn how to understand them better); it probably
> isn't
> > necessary to chop out a cavity in the deck and reinforce the bolt holes
> with
> > epoxy.
> >
> > Best,
> >
> > Roger 148
> >
> > PS - Wife Jeanne and I drove from Pittsburgh on Jan 8 to attend the
> > Chesapeake Bay Alberg 30 Association annual dinner.  What a great time we
> > had.  We have only been to a few Alberg events but felt at ease and at
> home
> > with this lovely group of people.  We hope to attend again next year to
> > discuss the river sailing characteristics of an A30 (seven years of on
> the
> > hard is probably long enough).  Thanks everyone for your hospitality.
> >
> >
> >
> > Sidebar - Understanding Engineers
> >
> >
> > Two engineering students were talking on a university campus when one
> said,
> > 'Where did you get such a great bike?'
> >
> > The first engineer replied, 'Well, I was walking along yesterday, minding
> my
> > own business, when a beautiful woman rode up on this bike, threw it to
> the
> > ground, took off all her clothes and said, 'Take what you want.'
> >
> > The second engineer nodded approvingly and said, 'Good choice; the
> clothes
> > probably wouldn't have fit you anyway.'
> >
> >
> > Understanding Engineers - Take Two
> >
> > To the optimist, the glass is half full. To the pessimist, the glass is
> half
> > empty. To the engineer, the glass is twice as big as it needs to be.
> >
> >
> > Understanding Engineers - Take Three
> >
> > A priest, a doctor, and an engineer were waiting one morning for a
> > particularly slow group of golfers.
> >
> > The engineer fumed, 'What' s with those guys? We must have been waiting
> for
> > fifteen minutes!'
> >
> > The doctor chimed in, 'I don't know, but I've never seen such inept
> golf!'
> >
> > The priest said, 'Here comes the greens keeper. Let's have a word with
> him.'
> > He said, 'Hello, George! what's wrong with that group ahead of us?
> They're
> > rather slow, aren't they?'
> >
> > The greens keeper replied, 'Oh, yes. That's a group of blind fire
> fighters.
> > They lost their sight saving our clubhouse from a fire last year, so we
> > always let them play for free anytime.'
> >
> > The group fell silent.
> >
> > The priest said, 'That's so sad I think I will say a special prayer for
> them
> > tonight.'
> >
> > The doctor said, 'Good idea. I'm going to contact my ophthalmologist
> > colleague and see if there's anything he can do for them.'
> >
> > The engineer said, 'Why can't they play at night?'
> >
> >
> > Understanding Engineers - Take Four
> >
> > What is the difference between mechanical engineers and civil engineers?
> > Mechanical engineers build weapons and civil engineers build targets.
> >
> >
> > Understanding Engineers - Take Five
> >
> > The graduate with a science degree asks, 'Why does it work?' The graduate
> > with an engineering degree asks, 'How does it work?' The graduate with an
> > accounting degree asks, 'How much will it cost?' The graduate with an
> arts
> > degree asks, 'Do you want fries with that?'
> >
> >
> > Understanding Engineers - Take Six
> >
> > Three engineering students were gathered together discussing the possible
> > designers of the human body. One said, 'It was a mechanical engineer.
> Just
> > look at all the joints.' Another said, 'No, it was an electrical
> engineer.
> > The nervous system has many thousands of electrical connections. ' The
> last
> > one said, 'No, actually it had to have been a civil engineer. Who else
> would
> > run a toxic waste pipeline through a recreational area?'
> >
> >
> > Understanding Engineers - Take Seven
> >
> > Normal people (particularly Albergers) believe that if it ain't broke,
> don't
> > fix it. Engineers believe that if it ain't broke, it doesn't have enough
> > features yet.
> >
> >
> > Understanding Engineers - Take Eight
> >
> > An engineer was crossing a road one day, when a frog called out to him
> and
> > said, 'If you kiss me, I'll turn into a beautiful princess.'
> >
> > He bent over, picked up the frog and put it in his pocket.
> >
> > The frog spoke up again and said, 'If you kiss me and turn me back into a
> > beautiful princess, I will stay with you for one week.'
> >
> > The engineer took the frog out of his pocket, smiled at it and returned
> it
> > to the pocket.
> >
> > The frog then cried out, 'If you kiss me and turn me back into a
> Princess,
> > I'll stay with you for one week and do ANYTHING you want.'
> >
> > Again, the engineer took the frog out, smiled at it and put it back into
> his
> > pocket.
> >
> > Finally, the frog asked, 'What is the matter? I've told you I'm a
> beautiful
> > princess and that I'll stay with you for one week and do anything you
> want.
> > Why won't you kiss me?'
> >
> > The engineer said, 'Look, I'm an engineer. I don't have time for a
> > girlfriend, but a talking frog, now that's cool.
> >
> >
> >
> > _______________________________________________
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>
>
> _______________________________________________
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> Please support them.
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