[Public-List] Mast beam almost finished!

[Glenn]

I had the same problem when I replaced my beam.  SS 1/4" bolts only come in 4" or 5" lengths. Anything longer is either 5/16 or 3/8, so they had to,drill half way to put nuts on.  Cant remember for sure but I think I had to go with 5/16" to reach the bottom of the beam, or maybe special order 1/4 x 6" bolts...

Gpb

Sent from my iPad

On Oct 26, 2013, at 4:57 PM, Mike Lehman <sail_505 at hotmail.com> wrote:

> I believe that one of the problems with the original bolts was that Whitby drilled VERY deep countersinks for the nuts on the bottom of the beam. The ones I have seen were drilled about 1/2 way thru the beam and the holes are on the worst possible location where the main downward force is applied. The main contributing factor to beam failure was the glue failed.
> 
> 
> ~~~_/)_/)~~ Mike Lehman ~~_/)~~~
> 
> 
> -----Original Message----- From: Jeffrey
> Sent: Saturday, October 26, 2013 8:11 AM
> To: Alberg 30 Public List -- open to all
> Subject: Re: [Public-List] Mast beam almost finished!
> 
> Thanks Glen.
> 
> You are probably right about using the through bolts.  I'm still
> trying to get my head around the forces on the last plate. Obviously
> down. But then I'm sure there's some pushing to the side, depending on
> the tack.  What I'm thinking is that the bolts holding down the mast
> plate only need to resist force in sheer, so that depth wouldn't
> matter after a certain point.  Shorter lag bolts that are thicker
> might be stronger than thinner through - bolts?
> 
> 
> jeff
> 
> Jeffrey Fongemie
> 
> Seagrass
> Alberg 30 #116
> Boothbay Harbor Maine
> 
> 
> 
> 
> 
> 
> On Sat, Oct 26, 2013 at 2:19 AM, Glenn <brooks.glenn at comcast.net> wrote:
>> Hi Jeff,  i had the same concern when I replaced my beam.  Eventually I drilled the bolt holes and thru bolted.  My reasoning is that all the boats have these bolts with no failures in 45 years so it is a proven method.   Also I didnt think I would gain anything by using lag bolts. They wont give you the structural integrity of thru bolts and will likely pull out if the mast ever did go over.  At worst lag bolts have a high risk for  creating pockets for water penetration and early dry rot.
>> 
>> On that cheerful note....
>> 
>> Glenn
>> dolce 318
>> 
>> Sent from my iPad
>> 
>> On Oct 26, 2013, at 12:13 AM, Dominic Amann <dominic.amann at gmail.com> wrote:
>> 
>>> I suspect that bolting through will not introduce much more weakness than
>>> drilled in lag bolts. Bear in mind that the failure you were observing was
>>> a delamination of the beam, and I think through bolts would actually help
>>> prevent that.
>>> 
>>> 
>>> On Fri, Oct 25, 2013 at 4:10 PM, George Dinwiddie
>>> <gdinwiddie at alberg30.org>wrote:
>>> 
>>>> Jeff,
>>>> 
>>>> On 10/24/13 7:17 AM, Jeffrey wrote:
>>>> 
>>>>> Hi everyone,
>>>>> 
>>>>> I'm nearly done replacing my mast beam. I've got the beam in, the
>>>>> tabbing finished and the posts reinforced.
>>>>> 
>>>>> http://216.172.166.167/~**seagrass/ <http://216.172.166.167/~seagrass/>
>>>>> 
>>>> 
>>>> Nice work, and a very nice description.
>>>> 
>>>> I still need to decide on how to deal with the bolts, that on the
>>>>> original beam, went through the mast step and right through the beam.
>>>>> I don't think bolts going all the way through the beam are necessary
>>>>> and will weaken the beam. I'm thinking of using some lag bolts that
>>>>> will go an inch or so into the beam.
>>>>> 
>>>> 
>>>> - George
>>>> 
>>>> --
>>>> ------------------------------**------------------------------**
>>>> ----------
>>>> When I remember bygone days                         George Dinwiddie
>>>> I think how evening follows morn;            gdinwiddie at alberg30.org
>>>> So many I loved were not yet dead,           http://www.Alberg30.org
>>>> So many I love were not yet born.                          also see:
>>>>              'The Middle' by Ogden Nash     http://idiacomputing.com
>>>> ------------------------------**------------------------------**
>>>> ----------
>>>> 
>>>> 
>>>> 
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>>> 
>>> 
>>> 
>>> --
>>> 
>>> 
>>> Dominic Amann
>>> M 416-270-4587
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> 
> 
> -- 
> ______________
> 
> Jeffrey Fongemie
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