[C38] boom failure

Mon Jul 20 11:17:01 EDT 2009

Unrelated subject anyone know the spec for jib sheets with a 135%.
Thanks

Bill Flying Goose

On Sun, Jul 19, 2009 at 3:02 PM, Max Soto <maxsoto at gmail.com> wrote:

> Glen, Just in case you need it for Lefiell, here's the Catalina spec sheet
> for our boom.
> Regards,
>
> Max Soto
> C38 #198 ESTANCIA
> Puntarenas, Costa Rica
>
> 2009/7/19 David Epstein <davidepstein at seicontrol.com>
>
>  Glenn,
>>
>> Sorry to hear of your misfortune.   Your boom was most likely made by
>>
>> *LeFiell Manufacturing Company
>> *13700 Firestone Blvd
>> Santa Fe Springs, CA 90670 USA
>> Tel: (800) 451-5971, FAX (800) 373-3361
>>  www.lefiell.com
>>
>> Good luck!
>>
>>
>> David Epstein
>> SuperStar, #122, Marina del Rey
>>
>>
>>
>>
>> At 10:23 AM 7/19/2009, Glenn Terry wrote:
>>
>> Tom,
>>
>> Very interesting.  A repair would save a lot of time not having to remount
>> all the hardware on a new boom.
>>
>> What kind of preparation did you do at the break?  Did you remove any
>> metal, square off the break, paint removal, etc.?
>>
>> The diamond shaped reenforcement tabs would solve several issues.
>>
>> How was the splint constructed.  If it laid directly on the mast it would
>> interfere with weld area.  Did you block it out from the mast or was it
>> temporary so the initial welds could be made and then removed to complete
>> the project.
>>
>> The metal fabrication shop I have used in the past has the ability to make
>> the jig and align it spot on.
>>
>> Any more information you can give me would be appreciated.
>>
>> Regards,
>>
>> G!enn
>>
>>
>> Tom T. wrote:
>>
>>
>> Hi Glenn,
>>
>> I can't name a good replacement for your boom but before you do that,
>> let
>> me tell you of another experience I once had that may help you.
>>
>> We had a highly modified South Coast 22 once that I used for design
>> experiments.  It had a very efficient hollow steel keel that was
>> bottom
>> weighted with lead.  The keel weighed 550 lbs, same as the original
>> iron
>> keel but my center of gravity was much lower because of the bottom
>> weight
>> of the new keel.
>>
>> We were sailing in a stiff breeze and really flying when my mast pumped
>> forward in a puff making the mast fail at the spreaders.  The whole
>> mast
>> and sails came crashing down and we slowly retrieved the sails, shrouds,
>> boom and mast halves and motored back to port.
>>
>> I salvaged that broken mast.  We made a splint of wood and clamped
>> the two
>> pieces of the mast together and welded them back together.  Then we
>> took a
>> piece of another mast, slightly larger than ours, and cut diamond shaped
>> pieces to overlay the welded area to permanently splint the damaged
>> area.
>>
>> After we repaired the mast, it looked like the factory had made the mast
>> with the reinforced section welded at the weak spreader area.  Not
>> only did
>> we salvage the mast, it was now much stronger than originally and not
>> prone
>> to future failure.
>>
>> The key to this repair is the diamond shaped plates made from another
>> mast
>> to overlay the repair area.  The reason for diamond shape is to not
>> concentrate the weld area of the plates.
>>
>> In my opinion, all masts and booms should come from the factory with
>> these
>> diamond shaped reinforcements.  The failure point of any mast or
>> boom is
>> usually where either the shrouds meet on the mast or the vang meets on
>> the
>> boom.  Those points are the highest strain points weakened by holes
>> drilled
>> through them and the diamond plate weld procedure makes those
>> points
>> stronger than the rest, as they should be.
>>
>> You don't personally have to own a MIG, TIG, or any other type of welder
>> to
>> do this, the preparation is the key element of a good repair.
>> Anyone can
>> make the wood splint, find a piece of old mast or have some aluminum
>> plates
>> rolled and fabricated from a metal shop if not successful in finding a
>> mast
>> stub for the metal overlay splint, and grinding a good fillets on the
>> weld
>> edges of all pieces.
>>
>> Once this preparation is done, any good weld shop equipped to weld
>> aluminum
>> can weld the mast together at a minimum of expense.  Like an auto
>> collision
>> repair, it's the preparation that cost the most, not the final painting
>> of
>> the car.  Same here, prep the mast properly and make a good splint
>> from
>> some straight wood and the repair price should be very small compared to
>> the price of a new boom, let alone the fact that your repaired boom
>> would
>> be actually much stronger than a new boom.
>>
>> Email me if you want more details.
>>
>> Tom Troncalli
>> Renata #95
>>
>>
>>
>>
>> [Original Message]
>> From: Glenn Terry<Glenn.Terry at Sun.COM> <Glenn.Terry at Sun.COM>
>> To: Catalina 38 Listserve
>> <listserve at catalina38.org> <listserve at catalina38.org>
>> Date: 7/18/2009 11:42:52 PM
>> Subject: [C38] boom failure
>>
>> I had a rookie at the helm and he executed a perfect uncontrolled
>> jibe.
>> The boom broke at boom vang mount.
>>
>> Can anyone give advice in the replacement of the boom?
>>
>> Regards,
>>
>> G!enn
>>
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>>
>>
>> --
>> Glenn Terry
>> OEM Software Licensing
>> Sun Microsystems, Inc.
>> 4180 Network Circle
>> USCA18-312
>> Santa Clara, CA 95054
>> w-408-404-8966  x4-0966
>> f-408-404-8966glenn.terry at sun.com
>>
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>>
>>  David Epstein
>> President, Sound Solutions
>> Chairman, CEA TechHome Division
>> Member of the CEA Board of Industry Leaders
>> Member, CEA Division Executive Board
>> Tel 310.398.0032
>> Fax 310.398.0036
>>  www.soundsolutions.com
>> www.ce.org
>>
>>
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>>
>
>
> --
>
>
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-- 
W H Knowles
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