[Public-List] corroded rudder

[Gordon Laco]

Sounds like good, well thought out advice to me.

Gordon Laco
www.gordonlaco.com




> On Mar 15, 2021, at 11:28 AM, Michael Connolly via Public-List <public-list at lists.alberg30.org> wrote:
> 
> Stephen,
> 5/8" is .625. The only drawings I have for later boats are from 1969 and the same as those on the A-30 Web site. They illustrate a 3/4" shaft being used as the middle pivot. Two 5/16" pins are fit into this 3/4" shaft (which are only 2" long) and the entire mess is embedded into the rudder blade along the front edge. Because the rudder stock is 1" in diameter I believe that it is NOT continuous along the front edge of the rudder.  There is a section from the tiller head down to the upper side of the prop aperature and then a short 9" section with the lower 1/2" pivot pin for the shoe.
> 
> The 3/4" middle pivot shaft is only 4-1/4" long.  If you would like to replace that section I would excavate along the front edge of the blade an inch or so above and below the existing shaft and expose its entire length. Expose it back to where it rounds back to be tangent to the leading edge of the blade.  I would then try to clamp something onto the exposed shaft and use a slide hammer to remove the pivot shaft. The drawings don't show anything on the tip of the 5/16" pins or any threads along their lenght, so they might just extract themselves without you having the excavate them and thus disrupt the blade at all. This way you can fashion a new pivot with new pins to insert back into the front edge of the blade.
> 
> Back to the original pivot you measured @ .60". How did you arrive at only 36% of the original strength from an original diameter of 3/4"?  Did you believe that the pivot was 1" in dia. when new?
> 
> The above is assuming the construction of your rudder is the same as for the 1969 boats.  Remove the tiller so you can push the rudder all the way forward and see if you can get to the entire front edge of the pivot area. Another option for the slide hammer clamp would be to tap into the leading edge of the exposed pivot and screw in some shafts to attach the slide hammer onto. Look at the drawing to be sure you don't tap into the shaft directly across from the embedded pins.  
> I would still attempt to do all this without removing the rudder from the boat. If all is sound above the middle pivot, leave well enough alone. George has posted the drawings which I have referred to in this description.
> Stephen, I hope you don't think I was suggesting a fix that wasn't seaworthy. I would never do that to anyone. Mr. Kirk who circumnavated with his A-30 effected a similar fix somewhere in South America which served him well.  Expense was not my motive, but undoing more than needed was. Please keep us informed on how you proceed. We all can learn from your experience.
> Michael #133
>> On 03/14/2021 5:52 PM Stephen Gwyn via Public-List <public-list at lists.alberg30.org> wrote:
>> 
>> 
>> Hi,
>> 
>> While there is some "meat" left at the middle bearing, when I put
>> my calipers on the shaft, find that 0.6 inches are left, which translates to
>> just 36% of the original strength. Not great. And that 0.6 inches was 
>> measured
>> on top of the crud; there will be less left after sanding down to clean 
>> metal.
>> Basically, the approach of just cleaning it up and putting in a delrin 
>> bushing,
>> while seductively cheap and easy, isn't really a seaworthy solution 
>> unless I
>> confine my sailing to quiet weather.
>> 
>> I have a 1972 boat, #495. None of the pictures on the website are from
>> that era, as far as I can figure out. The older boats also had fibreglass
>> tube going up to the cockpit, above the waterline. Mine has a stuffing
>> box at the hull.
>> 
>> What I'm trying to get from this group is some idea how the later
>> rudders were built, whether it was all one continuous carefully bent 
>> shaft, or
>> two parts or...
>> 
>> SG
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