[C320-list] Check your stem fitting - near catastrophic failure to C320

Thu Aug 13 11:48:59 PDT 2015

Jeff

I will do that, certainly; A bit busy for a day or two but in the next few days, fo sure

Graeme

On 13 Aug 2015, at 18:47, Jeff Hare <catalina at thehares.com> wrote:

> Hi Graeme,
> 
> It would be great if you could put all those pics in your photo gallery on
> the C320 website.  Tinypic is not a safe website to browse because the types
> of ads they allow can contain malicious JavaScript or flash.
> 
> To add pictures on the Catalina 320 International Association Website, you
> should be a member or have an account to log into. 
> 
> 1) Log into the Catalina320.com website
> 
> 2) In the "My Account" menu, you should see either "Create Photo Album" or
> "My Photo Album".  Choose this option to go to your photo album.
> 
> 3) In the blue bar near the top it'll have a little dropdown menu that says
> "Options".  Choose "Add Media" and click "Go"
> 
> 4) It'll give you a form that lets you upload 4 pictures at a time.  Browse
> for the picture, fill out any description/title info you want to include.
> If you fill in keywords, it'll be searchable.
> 
> 5) Click "Save" at the bottom of the page (may have to scroll down).
> 
> -Jeff Hare
> 
> 
> -----Original Message-----
> From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf
> Of Graeme Clark
> Sent: Wednesday, August 12, 2015 11:46 AM
> To: C320-List at Catalina320.com
> Subject: Re: [C320-list] Check your stem fitting - near catastrophic failure
> to C320
> 
> Further updates on this
> 
> The following photo (which you will need to copy the link and paste into
> your browser, to view) shows the fracture face of the stem head fitting.
> You can quite clearly see where the cracks have started (one on each side)
> and how it has progressed, with a series of concentric semicircles. 
> Obviously the darker rust marks are where the crack started, ie it has had
> longer to rust, and I believe this is essentially 'crevice corrosion'
> 
> The 'clean' un-rusted part is all that was holding everything together
> before it gave way!
> 
> ( Many if not most of you will hopefully already be aware of this , but for
> those that aren't, basically, even stainless steel will rust if the water is
> de-oxygenated which happens wehre it stagnates in tiny little cracks and
> crevices)
> 
> http://i59.tinypic.com/9zoaqf.jpg
> and
> http://i58.tinypic.com/30c595i.jpg
> 
> My own boat http://i58.tinypic.com/2jcbqdk.jpg seems to have a hairline
> crack in the weld and will require further inspection.  The identical
> fitting from a Catalina 36 is shown for comparison in these other photos
> http://i62.tinypic.com/116tjyr.jpg
> 
> Strongly suggest that this is worth double checking on your own boat!
> 
> HGraeme
> #366
> 
> 
> 
> 
> On 4 Aug 2015, at 16:42, Marko Jamnik <markojamnik55 at gmail.com> wrote:
> 
>> Hello Graeme
>> 
>> Since my sail number is 304 and built in '95. I will check my situation
> and take a picture. Once again it could be just that one but worth while
> having  an overall inspection.
>> Thanks for the heads up
>> 
>> MarkoJamnik
>> Marquesas 304 Lake Ontario
>> 
>> 
>> 
>> On 2015-08-04, at 11:17 AM, Graeme Clark <cg at skyflyer.co.uk> wrote:
>> 
>>> Or try this link
>>> 
>>> http://oi58.tinypic.com/t8lwz9.jpg
>>> 
>>> G
>>> 
>>> Sent from mobile: please excuse typos etc.!
>>> 
>>> 
>>>> On 4 Aug 2015, at 15:55, Daryl Hunt <drhunt at rochester.rr.com> wrote:
>>>> 
>>>> Hi Graeme,
>>>> FYI, when I click on the tinypic link I don't see the image.
>>>> 
>>>> /Best regards,
>>>> /
>>>> 
>>>> /Daryl
>>>> '99 C320 #660 Believe
>>>> /
>>>> 
>>>> 
>>>>> On 8/04/15 10:15 AM, Graeme Clark wrote:
>>>>> 
>>>>> Just to correct my own post!
>>>>> 
>>>>> The perspective of the picture I posted made me wrongly state there was
> a backing plate, I can now see that it is in fact looking at the entire
> broken cross-section of the vertical bar to which the forestay (headstay?)
> connects.
>>>>> 
>>>>> You can see a tiny rusty part, which someone with better engineering
> knowledge may confirm to be crevice corrosion -  almost certainly starting
> from a tiny pit where the  triangular gussets are welded in place?
>>>>> 
>>>>> Still very tricky to spot and worth a good look at your own boat to
> check for a similar issue maybe?
>>>>> 
>>>>> Graeme
>>>>> 
>>>>>> On 4 Aug 2015, at 13:12, Graeme Clark <cg at skyflyer.co.uk> wrote:
>>>>>> 
>>>>>> The C320 that I used to share before buying my own, suffered a 
>>>>>> near catastrophic failure of the stem fitting that attaches the 
>>>>>> forestay to the bow, last week;
>>>>>> 
>>>>>> How they didn't lose the mast I don't know
>>>>>> 
>>>>>> The boat is  serial no 303 built in 1996
>>>>>> 
>>>>>> This link, pasted into your browser, will show the failure, the 
>>>>>> red arrow is the fractured surface
>>>>>> http://tinypic.com/r/t8lwz9/8
>>>>>> (by the way, the halyard you see is the jury-rig to keep the mast 
>>>>>> up!)
>>>>>> 
>>>>>> For interest you may wish to see the current design of replacement 
>>>>>> offered by CD 
>>>>>> http://www.catalinadirect.com/index.cfm/product/2573_699/stem-fitt
>>>>>> ing-c-320-c-34-c-36.cfm
>>>>>> 
>>>>>> Note that CD state they have removed the unnecessary and non
> structural triangular gussets that are clearly visible on the part that
> failed.
>>>>>> 
>>>>>> But you will also note that there is a 'backing plate' joining those
> two gussets that is located close to and to the rear of the part that
> failed.
>>>>>> 
>>>>>> My guess is that a small defect or other stress concentration was
> present on the rear of the vertical bar and over the years repeated flexing
> has caused a fatigue crack to develop and propagate.
>>>>>> 
>>>>>> The point is that it is very difficult to see this area, and I think
> any crack would be very unlikely to be spotted with a routine cursory
> inspection.
>>>>>> 
>>>>>> I have no idea if there's any history of these parts failing, but If
> so I was not aware of it.
>>>>>> 
>>>>>> I would strongly recommend a careful  inspection of your own boat to
> make sure that no crack is developing in the same area.
>>>>>> 
>>>>>> I hope the above description is clear, but if I have confused you, 
>>>>>> please ask away and I will try and  explain further
>>>>>> 
>>>>>> Regards
>>>>>> 
>>>>>> Graeme
>>>>>> #366, Jaskar
>>>> 
>>>> 
>>>> 
>>>> ---
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>>>> https://www.avast.com/antivirus
>> 
> 