[C320-list] SS Clamp Failure

[Scott Thompson]

The 316 clamps tend to be labeled as such because they cost twice as 
much (due, I suspect, to their high nickel content).    If it just says 
"300" then it's probably "300 series" which could mean any one of the 
marine grades of stainless steel but most likely is 304.  Unfortunately, 
the two types often sit side by side in stores, with no clear guidance 
for why some cost more than others for apparently identical clamps. 

bruceheyman at cox.net wrote:
> Kirk,
> The only numbers I could find on the clamps were 300.  Unfortunately the new clamps I bought had the same numbers.
> How did the thru hull handle break off?  Was it frozen up?
> Bruce
> Somerset 671 SoCal
> Sent via BlackBerry by AT&T
>
> -----Original Message-----
> From: "Kirk McCullough" <kirk.mccullough at telus.net>
>
> Date: Sun, 30 Dec 2007 17:14:33 
> To:"'C320-List'" <c320-list at catalina320.com>
> Subject: Re: [C320-list] SS Clamp Failure
>
>
> I have the original clamps on Boomerang a 1994 boat with no signs of
> corrosion and no failures. I suspect that your clamps are a poor quality
> stainless steel. I suppose they are SS, but for a marine application we need
> something like 304 or 316 SS.
>
> Good thing you found it before you had a major failure at sea.
>
> We lost the through hull valve while pumping out at sea once; the handle
> broke off and a leak path through the handle fastener allowed 50 or more
> gallons of water in before I could stop the flow. I check my through hulls
> and hose clamps very frequently now...... but I've never had a clamp fail
> just the Marlon thru hull valve.
>
> Kirk
> #124
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Bruce Heyman
> Sent: 28 December 2007 10:03
> To: 'C320-List'
> Subject: Re: [C320-list] SS Clamp Failure
>
> Barry,
> Surprisingly they did not fail at the gear base which is where I would have
> expected.  Most of them failed along the strap where it is relieved to allow
> for the screw thread.  The metal was very brittle and quickly snapped if you
> flexed them.  I'm sure they are the original clamps applied at the factory
> about 8 years ago.
> Bruce
> Somerset #671 SoCal 
>
> -----Original Message-----
> From: c320-list-bounces at catalina320.com
> [mailto:c320-list-bounces at catalina320.com] On Behalf Of Barry Fahrer
> Sent: Friday, December 28, 2007 8:42 AM
> To: C320-List
> Subject: Re: [C320-list] SS Clamp Failure
>
> I am very surprised that your clamps failed.  How did they fail ?  I guess 
> it is possible that the acid fumes from the battery could be causing a 
> problem.
> I have only seen some cheap hose clamps fail because the metal around the 
> gear base couldn't withstand the tension.
> You might want to talk to the manufacturer and find out if they
> are warranted at all. BARRY --... ...-- 
>
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