[Public-list] bronze rudder post replacement
Elaine and Brian Timmins
timmins at optonline.net
Wed Oct 18 02:47:55 PDT 2006
If you have trouble finding Silicon-Bronze, most prop shops should be able
to sell it to you.
Brian ex#497
----- Original Message -----
From: "John Birch" <Sunstone at cogeco.ca>
To: "Alberg 30 Public List -- open to all" <public-list at alberg30.org>
Sent: Wednesday, October 18, 2006 1:07 AM
Subject: Re: [Public-list] bronze rudder post replacement
> Try to get silicon bronze, easier said than done - there is a lot of stuff
> out there called bronze which is closer to brass ... some "bronze" even
> has
> zinc in it - you don't want that. Also I would suggest you want forged,
> rolled or extruded bronze not cast - plain castings are not nearly as
> strong.
>
> Same with bolts and screws - silicon bronze. A "great deal" usually isn't,
> its often crap bronze - use a reputable specialist supplier - up here I go
> to Pacific Fasteners off Chauncey Drive off Islington in Toronto.
>
> Just a suggestion
>
> Cheers,
> John
>
> ----- Original Message -----
> From: <brooks.glenn at comcast.net>
> To: "Alberg 30 Public List -- open to all" <public-list at alberg30.org>;
> "Alberg 30 Public List -- open to all" <public-list at alberg30.org>
> Sent: Tuesday, October 17, 2006 11:51 PM
> Subject: Re: [Public-list] bronze rudder post replacement
>
>
>> Hello Chris,
>>
>> I would definitely replace with bronze, except probably all the metal in
>> the rudder should be replaced bronze. I just took my 30 yr old bronze
>> shafts ( and rudder from which they recently were attached) to a
>> commercial boat yard/machine shop. The shop owner said his experience is
>> that short gudeon shafts are very common on sailboats, particularly if
>> located just below the prop aperture, ala A-30's... Two small pins run
>> into the rudder centerline are all that are needed to hold the shaft from
>> turning. B
>> ronze shaft material is commonly available in many sizes. Any good
>> machine shop could turn the grudens/(pintels??) out of bronze stock, +
>> there are several foundries on the internet who sell cast pieces...
>>
>> Here's what I discovered when I removed both upper and lower shafts,
>> plus
>> the 6" mid rudder grudeon shaft... Found out
>> the upper shaft runs from the tiller assembly, down through the stop
>> water
>> in the hull, then down the leading edge of the rudder, then bends
>> rearward
>> around the inside of the prop aperture to about 2/3d's of the way to the
>> bottom leading edge of the rudder. The shaft sort of zig zags ( picture
>> half a carton ligthing bolt)to get around the back side of the prop
>> aperture, and runs behind the grudeon shaft about 4-5 inches. The
>> machine
>> shop guy says this design gives terrific additional strength and tranmits
>> a great deal of torque down through the rudder, Thus helping prevent the
>> shaft from twisting in the F/G and foam rudder body.
>>
>> I am goling to have the shop extend the new shaft anothor 18" or so down
>> to the bottom of the rudder- replacaing the origianl 8" lower stock wikth
>> this all new, full length piece. I cut through about 4 ea 5/16" pins
>> bedded laterally through the rudder center line and seated in the shaft
>> itself. The pins also stop the shaft from torquing out of position.
>> Will put 4 or 5 pins through the new full length shaftin to the rudder
>> body to prevent twist.
>>
>> My existing upper and lower shaft is 1" bronze. Gudeon shaft origanlly
>> 3/4" bronze, but now 5/8 and crumbling rapidly, with 2 1/2" 5/16th
>> bronze
>> pins holding it from twisting.
>>
>> Bronze shaft stock is still commonly available, so I am going to stay
>> with
>> all bronze shafts. I wouldn't worry about casting the gudeon shaft. you
>> should be able to buy a piece of 3/4, 7/8 1", 1/18 and up, as you need.
>>
>> Also am thinking about having the shop make up a second set of
>> gudeon/pintels ( still havent figured out which is which), ie to add an
>> additional pivotpoint/support either at the top of the shaft just below
>> where the fairing leads into the full or above the rudder shoe... this
>> is probably overkill, but am going to Hawaii and Alaska in next couple of
>> years, so its just extra small insurance.
>>
>> BTW, the easiest way I found to cut out the FG material around the shaft
>> was to use a thin, high speed composite metal cutting wheel on my 4"
>> grinder. This cut a nice clean, vertical 3/16 slot through the FG
>> layers,
>> just like butter. Then hung up a bit on the shaft material, making a
>> nice
>> depth gauge for cleaning out just enough material to chisel out a channel
>> where the shaft was embedded in the original mold.
>>
>> I will grind out the top half of the rudder and reglass and pin
>> everything
>> back into place once the shop returns my proud and shiny, NEW full
>> length
>> bronze shaft assembly, and I fit it into the existing channel.
>>
>>
>> Also, I intend to have them machine a 5/8 or possibly 3/4" pin directly
>> out on the end of the new full length shaft assembly, and ream out the
>> rudder shoe to accept the new pin dimension. Will give lots more
>> strength
>> and longer life. Also might go with 1 1/8th" stock instead of existing
>> 1", and have then turn the top part down to 1" to fit the packing gland
>> in
>> the full. Again, small difference, but a lot of added strength and
>> larger
>> pin size for the next 30 years wear and tear.
>>
>> I spent a lot of time very tentatively cutting into the rudder to remove
>> the two lower pieces-- maybe 4 hours. Once the shape of the upper took
>> form, it went quicker. Now I wouldn't hesitate to whack the thing right
>> from the beginning, top to bottom in an hour or two, if I had to. Which
>> I
>> won't , because in 30 years the boat will be 60 years old and I'll be 90,
>> so probably will just sell it and buy another which already has the work
>> done.
>>
>> So, probably more info than you wanted to know, but it wasn't nearly the
>> fema disaster I was expecting. Iam very confident ( now) the whole thing
>> will go back together in short order, probably by end of the week, except
>> for curing time...
>>
>> PS. George, thanks Very Much for the followup info you sent. Very
>> helpfull anticipating how to do this thing!
>>
>> Glenn
>> Dolce #318
>>
>>
>> -------------- Original message ----------------------
>> From: "Chris Blain" <chris.blain at gmail.com>
>>> I have another question regarding this whole assembly- the mid rudder
>>> strap/gudeon - has anyone fabricated one from bronze strip, or is there
>>> a
>>> source for a cast one? My boat (an A35, but identical in rudder
>>> contruction,
>>> had a stainless strap which showed classical corrosion patterns and was
>>> almost gone, and I'd prefer to replace it with less prone to corrosion -
>>> bronze.
>>>
>>> Thanks,
>>> Chris
>>>
>>>
>>> On 10/17/06, brooks.glenn at comcast.net <brooks.glenn at comcast.net> wrote:
>>> >
>>> > Hi George,
>>> >
>>> > I would like to ask an additional question regarding your rudder
>>> > stock,
>>> > if
>>> > I may?
>>> >
>>> > Is your lower rudder shaft all one piece or two short pieces?
>>> >
>>> > I just opened up my lower rudder and found two short pieces 6-8" long:
>>> > one
>>> > at the bottom with the pin fitting into rudder shoe, the other at
>>> > mid-rudder
>>> > where it can be grabbed by the pintel/grudgeon assembly...Both have
>>> > two
>>> > 5/16" round pins several inches long bored into the rudder to keep
>>> > everything from spinning. The design seems a little light weight for
>>> > off
>>> > shore sailing...( but it has lasted 30 years now...)??
>>> >
>>> > Do you have any thoughts about replacing these two short ones with one
>>> > long shaft- aside from cost?
>>> >
>>> > Thanks much,
>>> >
>>> > Glenn
>>> > dolce #318
>>> > -------------- Original message ----------------------
>>> > From: George Dinwiddie <gdinwiddie at alberg30.org>
>>> > > brooks.glenn at comcast.net wrote:
>>> > > [snip]
>>> > > > Can anyone suggest the best way to do this?
>>> > >
>>> > > I don't know if it's best, but my approach is included in the
>>> > > Maintenance Manual. Basically I chiseled out the foam and removed
>>> > > the
>>> > > lower post, which was in a condition similar to yours. I had it cut
>>> > > off, drilled and tapped. I then put it back in the rudder with
>>> > > glass
>>> > > and epoxy and filled the voids with thickened epoxy.
>>> > >
>>> > > > PS, I really don't want to go stainless as the pintels and shoe
>>> > > > are
>>> > > > in excellent condition, and the rudder post mounted in the hull is
>>> > > > bronze.
>>> > >
>>> > > You really don't want to use stainless below the waterline. See
>>> > > http://alberg30.org/maintenance/Steering/CreviceCorrosion/
>>> > >
>>> > > --
>>> >
>>> >
>>> > > ----------------------------------------------------------------------
>>> > > When I remember bygone days George
>>> > > Dinwiddie
>>> > > I think how evening follows morn;
>>> > > gdinwiddie at alberg30.org
>>> > > So many I loved were not yet dead,
>>> > > http://www.Alberg30.org
>>> > > So many I love were not yet born.
>>> > > 'The Middle' by Ogden Nash
>>> >
>>> >
>>> > > ----------------------------------------------------------------------
>>> > >
>>> > >
>>> > >
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>>
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