[Public-list] bronze rudder post replacement

Tue Oct 17 20:51:27 PDT 2006

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. Bronze 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
> > >   ----------------------------------------------------------------------
> > >
> > >
> > >
> > > _______________________________________________
> > > These businesses support your Association:
> > > http://www.alberg30.org/store/A30supporters.html
> > > Please support them.
> > > _______________________________________________
> > > Public-list mailing list
> > > Public-list at alberg30.org
> > > http://alberg30.org/mailman/listinfo/public-list
> >
> >
> > _______________________________________________
> > These businesses support your Association:
> > http://www.alberg30.org/store/A30supporters.html
> > Please support them.
> > _______________________________________________
> > Public-list mailing list
> > Public-list at alberg30.org
> > http://alberg30.org/mailman/listinfo/public-list
> >
> _______________________________________________
> These businesses support your Association:
> http://www.alberg30.org/store/A30supporters.html
> Please support them.
> _______________________________________________
> Public-list mailing list
> Public-list at alberg30.org
> http://alberg30.org/mailman/listinfo/public-list

 1161143487.0