Rudder Gudgeons

<Home> <500 Auxiliary Machinery>

Added 03/09/2004


The rudder and gudgeon on my 8.7 are busted. Does anyone know
where I could find a rudder and gudgeon to replace the busted ones? has
anyone kept the molds for the rudder?

Thanks to all.

Ned, I think itís better if I first try to describe gudgeon so that we agree on the terms. It is composed of two halves which each comprise a section which holds the shaft then a section which has three screws that serve to tighten the two halves snug around the shaft (Iíll call it the middle section) and finally a "strap" that fastens the whole to the skeg. The metal screws holding the two halves together were originally SS 1/4" but Mike, the English sailor who helped me in Flores and then in Horta said they seemed too weak to him so I replaced them with 5/16" silicon bronze ones from Jamestown Distributors (with nuts of the same material). After I had taken the gudgeon off, I brought it to my friend Tip and told him that the shaft was 1 1/8" and he milled the flat of the section that hold the shaft and also of the "middle section" but did not touch the straps-When I re-assembled the guidgeon, I first tightened up the screws in the middle section so that the shaft would be held snuggly (If you tighten the straps first, you wonít be able to do that). I then cut the excess length of the screws and covered the straps and nuts with Bondo so as to fair the whole thing. This has held fine since spring 2000.


The rudder on my 8.3 is also loose in the gudgeon and I have it on
the to-do list for haulout next year. I was thinking that a bushing
of some kind had worn out but your post sounds like there is not
one. I haven't seen one of these gudgeons disassembled.

When you say "milled the flats" do you mean reduced the thickness of
the part of the gudgeon that attaches to the hull and take some off
where the curved part of the gudgeon meet? That would reduce the
diameter of the opening for the rudder post. How much did you take

Ned Tyler
Sara T
C8.3 #50

Pablo, somebody on the list recently posted that he had a spare 8.7 rudder with a 1 3/8" shaft for sale, but I can't remember who it was. If it's no longer available, Foss Foam is the source for rudders. As far as the lower gudgeon, what exactly do you mean by "busted" ? Mine had too much "slop" and a friend milled the flats on each half gudgeon so that the play between the gudgeon and shaft disappeared. If the gudgeon is broken, Iīm afraid the only solution would be to have another one cast. If you find a foundry that can do it, you might ask how many of us are interested in having a spare made so as to spread the cost. But you'd have to give the exact dimensions of yours to allow people to see whether they have exactly the same one.

pampero iv (8.7)


John: thanks for your suggestions. The part of the gudgeon attached to the rudder is missing (broke off). I guess I'll have to have another cast. I'll see what I do about the rudder. The rudder itself is not damaged, but the shaft is significantly bent. There is a chance it could be straightened so I may not need a new rudder, but, as you say, I don't have many choices regarding the gudgeon.
Thanks to all for your suggestions!

For the pair of gudgeons, mine got busted also. 2 years ago I had a small foundry in Tacoma cast new ones. The old gudgeons were used to make  a sand mold, I added bondo to account for shrinkage in the casting process, the foundry can explain or even do it for you. When the casting cools the mold is broken to release the parts. To have an investment mold made would be very expensive and would require approx 100 parts to break even. It was very cheap, only charged $45 for the pair. The machinist charged $80 to machine the 1.25in hole where rudder goes thru. He tacked the gudgeons together and chucked it up on his lathe, spinning the gudgeons and used a cutter for the hole. I was really lucky as the whole deal was inexpensive, $150 and only took 3 days from when I first contacted the foundry. Most places wanted $400 - $500 just for the castings with a lead time of 6 weeks! I was also in the yard at $20 a day so I was in a hurry.
Hopefully you can find a small foundry near you that will cast your new gudgeons.

Pablo, since you still have the complete rudder, one solution could be to order a new shaft (I got one from McMaster-Carr) and get a piece of  Stainless Steel plate ( might have what you need). Get the plan of the shaft and plate from justin ( and get a shop to mill the grooves for the plate and the keyway at the top. Get the plate welded on. Then buy some marine (or exterior) plywood (say 3/4" thick) and epoxy thicknesses of it to be able to make the two halves which will apply (duly routed for the shaft) to the rudder shaft. Epoxy them together with a few bronze screws for strength. Then you can start planeing it down to the original profile with a belt sander (the lines of the various plies will guide you in the process). When youíre finished, one or two layers of fiberglass cloth epoxied to the plywood will finish the job. Quite a bit of manual work, but a damn sight cheaper and a hell of a lot stronger than the original rudder which is only foam and gel coat....