[Public-List] foredeck compression

Fri Jan 21 15:16:34 PST 2011

Roger,

To follow up on Gordon"s dicussion, what we try to achieve is an epoxy
bushing inside of the bolt hole, say approx.1/8 -1/4 inch side wall
thickness. this can be achieved by chucking a bent nial or the long
end of a smallsize allen wrech or simillar obect ina drill and workig
it up and down inside the bolt hole to rmove some of the balsabtween
the fiberglass . Then Plug tape of the bottom of the hole and fill
with thickened epoxy. Then redrill to hole ot the proper dia.

I would also recommed a backup plate under all cleats.
Jim Allocco

On Tue, Jan 18, 2011 at 3:34 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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