[Rhodes22-list] Attach pully to spreader arm ??

[Michael D. Weisner]

Rummy,

The use of two dissimilar metals such as stainless steel and aluminum is 
routinely done, particularly where there is no conductive path to cause 
"galvanic corrosion", which is what you are referring to.  Most of the 
rigging hardware on my R22 is stainless steel, attached to aluminum by 
stainless fasteners.

The important fact is that there be little or no contact between the metals. 
The rate of galvanic corrosion is related directly to the ratio of cathode 
area (stainless) to anode area (aluminum).  A clamp has a smaller contact 
area than a strap due to the holes in the band.  In addition, the aluminum 
spreader is "anodized" and the stainless steel is "passivated", specifically 
reducing the activity of the surfaces.  An insulating material could be 
placed around the spreader, under the clamp, to reduce the area of contact 
further.

The clamp does indeed work well, as I have used it on both spreaders for 
over 20 years to attach lighting and blocks.  There has been no 
"disintegration" observed, although I must admit, I used tape around the 
spreader for safety.

Mike
s/v Shanghai'd Summer ('81)
Nissequogue River, NY

From: <R22RumRunner at aol.com>Sent: Monday, April 21, 2008 11:27 AM
> Mike,
> A hose clamp would certainly work, but it's not recommended. The hose 
> clamp
> is stainless and the spreaders are aluminum. It's not wise to have two
> different  metals touching. In this case I would think the aluminum, being 
> the softer
> metal, would disintegrate first. I also don't like drilling holes in a
> narrow  piece of metal that relies on it's stiffness to accomplish its 
> job. Plastic
> wire  ties would work, but they will deteriorate from UV exposure. I would
> replace  them annually.
>
> Rummy
>
>
> In a message dated 4/21/2008 11:02:24 A.M. Eastern Daylight Time,
> mweisner at ebsmed.com writes:
>
> Hank  & Ed,
>
> Hank: Yes, the clamp can be opened and reassembled.  The  only problem is
> that some folks may bend the clamp in an attempt to open  it wide enough,
> putting a kink in the band.  Also, I have seen clamps  damaged when the 
> screw
> cuts into the band when attempting to rethread  during reassembly.  I 
> thought
> that the cotter pin was the simplest  and most foolproof solution (that's 
> why
> I didn't advocate removing the  shroud side.)
>
> Ed: Twist-tie?  Surely you jest!  They rust,  leave marks, etc.  But, you 
> got
> me to thinking.  Why not use a  Tywrap or two?  This is even easier that a
> hose clamp, although  nowhere near as strong (just add a few more) or 
> durable
> (replace Tywrap(s)  every season.)
>
> Mike
> s/v Shanghai'd Summer ('81)
> Nissequogue  River, NY
>
>
> From: "Hank" <hnw555 at gmail.com>Sent: Monday, April  21, 2008 9:17 AM
>> Mike,
>>
>> Why remove the spreader?   The clamp can be opened and put around the
>> spreader and then threaded  back together.
>>
>> Hank
>>
>>
>> On 4/21/08,  Michael D. Weisner <mweisner at ebsmed.com> wrote:
>>>
>>>  Rory,
>>>
>>> Have you tried a stainless steel hose  clamp?  The spreader can be 
>>> removed
>>> from the mast with a  single cotter pin and the clamp placed over the 
>>> bar.
>>> Replace the  cotter pin and use the clamp to hold a shackle and sheave 
>>> to
>>>  the
>>> bar.  I think that you will need a 1-1/4" diameter clamp  (from memory)
>>> but
>>> please measure the spreader  diameter and the shackle that you will use.
>>>
>>>  Mike
>>> s/v Shanghaid'd Summer ('81)
>>>     Nissequogue River, NY
>>>
>>> From: "R Orkin"  <roryorkin at verizon.net>Sent: Sunday, April 20, 2008 
>>> 7:09
>>>  PM
>>> >
>>> > I was thinking about attaching a pully to  the spreader arm. The 
>>> > object
>>> > would
>>> > be to  have a way to haul a light up a bit in order to get some light
>>>  over
>>> > the cockpit at night. Any thoughts on how to attach this  ??
>>> > I am reluctant to drill the  spreader arm. If anyone  has drilled it,
>>> > please
>>> > let me know..  Thanks
>>> >          Rory
>>>  >
>>> > -----
>>> > Rory Orkin
>>> >  Tilghman, Md
>>> > 2000 Recycled  Rhodes 22
>>> >  Duet ll
>>> > --
>>> > View this message in  context:
>>> >
>>>
> http://www.nabble.com/Attach-pully-to-spreader-arm----tp16800049p16800049.html
>>>  > Sent from the Rhodes 22 mailing list archive at Nabble.com.
>>>  >
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>>> >
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