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Theis, Greg, and Ebb;
Thanks to all of you for the help and ideas onthe wood suppliers and the bronze! Bloomington is close to me so I'll run up and have a look. I'll write or call Kettle Morain and the Caledonia Co. and Pekin.
Ebb, you're input is valued, I appreciate your thoughts and I will take heed! I only want to do this rudder once and as correct as possible. I will be wary since I know they will sell you anything just to make the sale. Such are the times in which we live! I have a good sailor friend that is a metallurgist so I'll get the assay and run it by him.
Jim
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Jim:
Kettle Morrain Hardwoods is in Caledonia, WI. There is no Caledonia company that I am aware of. Good Luck!
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Thanks Capt Jim,
Pearson didn't get it too wrong in the beginning. The class here went through this and discovered that manganese bronze was used for nearly all the cast fittings and the shaft. The stuff is expensive, but that is relative. The dynamic shaft/shoe combo lasted nigh onto 40 years until we came along to refurbish.
Have to amend this. So I looked it up:
manganese b....... Naval brass ......... Everdur
58.5 copper.........60 copper.......... 98.25 copper
39.25 zinc...........39.25 zinc..............0
1 tin..................75 tin...................0
.25 manganese.... 0..........................25
1 iron..................0.........................0
0.........................0....................... ..1.50 silicon
Tensile strength psi of rod.: Hard and soft:
m.b. 45,000 - 30,000. n.b. 63,000 - 56.000. Ev 70.000 - 40.000.
Looks like manganese and naval are just about the same. Well, alloying is still a mystery to me. I went with Everdur. Awhile ago I had an animated discussion with Roger at Bristol Bronze. He stongly supported his highly alloyed manganese, which. he said, Bristol had originally supplied Pearson for the A/Cs, including the shaft.:o
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Ebb, Thanks for the comparative assay on manganese and naval; boy they really are close; are you saying that Bristol Bronze has manganese rod in the sizes that we need: One Inch and 5/16's?
Theis, Thanks so much for the corrected address on Kettle Morain.
Jim
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This should be filed somewhere readily available by anyone contemplating rebuilding the ruddershoe or shaft. It will be useful before you are done. I'm making it an appendix to the manual and giving a copy to my mold maker. Thanks for the info and effort.
A while ago I did some searches for manganese bronze and naval bronze and turned up a couple sites that seemed to have rod in every size and alloy known to man so anyone looking for rod could consider that route. I'm waiting until I know the exact alloy of the new shoe and then matching that
for the ruddershaft and drift pins.
Tom
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Ebb
That is great information. Thanks. But you choosed Everdur, Roger prefers Manganese Bronze, and I assume the reason for the name Naval Brass is because it is for the Navy (as contrasted with an area of the body).
Your information raises the questions Why did you choose Ererdur, Why does the Navy prefer Naval Brass, and why does Roger prefer Manganese Bronze? I understand hardness is one reason.
What about the corrosion element/electrolysis of the compounds? Is it that one is a new and improved version of an earlier type? Can they all be machined by the average machinist? What about cost? As a point of reference, last year we discussed electrolysis and the need to have multiple anodes. Is there a linkage between electrolysis/anodes and manganese bronze - whereas corrosion is less of a problem with the other two compounds?
As for the mystery of compounds and mixtures, it is truly wondrous how a little of this or a little of that can change the properties of something - like adding a teaspoon of cayenne peppers to a bowl of otherwise edible spaghetti.
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Manganese bronze rod is available in all sizes. If you are going to make a traditional rudder, I would match the internal rods. too. The problem is getting the alloy only in the length you need, because it is sold in 6 and 12 foot lenghs. or however the supplier deals it from the foundry. [I have a couple of two foot pieces of 1" Everdur left over from my ruddershaft adventure that cost the price of gold, are two precious to get rid of, are too short to do anything with.]
I went with Everdur because I had already cast 338s new shoe in silicon.
I had reasoned with self that silicon is commonly available and that it was likely that any bronze in the water would be silicone.
I then found that B.B. would do castings to patterns I made.. Very cool. Roger is, IMCO, committed to manganese for static load fittings. My discussion with him, which was 95% listening, about my underwater choice in bronze, was when he came up with that manganese would last 100 years but silicon only 50. Bristol has made all the highend jewelry for all the great highend yachts forever. And that Bristol will suffer a fool like me makes Roger close to god. But m.b. over time disintergrates in modern salt water. I think we two ended with a stalemate.
I'm a 'doubting thomas.' There is no doubt that in water fittings on the A/Cs have a problem (in salt water and in marinas..) My reasoning is simple: there isn't enough other ingredients in silicon bronze to leach out and crumble the fitting. Which has happened with our boats, right? Manganese is the best bronze alloy for fittings under load above the waterline.
B.B. might be a source for m. rod. I think his prices are highend but fair. I would check local suppliers.
Bristol Bronze is very committed to resupplying his firms original fittings that Pearson used. But the original molds got lost and a pattern maker has not appeared to make authentic copys. If 338's shoe mold is succesful I'll donate it to the ACA or give it to Roger. [by the way for the nth time - Bristol also has a beefed up version of the 338's stem fitting (in m.b.) that I know he has sold to one Triton owner who was happy with it. I don't know how much. He cosiders the molds you send him as 'public domain.'
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I think the crucial observation is that no matter which alloy is chosen it will in all likelihood outlast the chooser. I've wondered if Pearson was as concerned as we have become. My guess is they called for naval bronze because that is what was most readily available at the time and it had been proven to work for centuries. But I've also found that naval bronze means different things to different people and wouldn't be surprised if Pearson left the mixture to the foundry. In the early 1960's the simplest solution would probably have been the most likely and using special alloys that weren't absolutely neccessary would have been unlikely.
Tom
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Good information. Thanks. You know, after everthing is taken into account, fresh water sailing is so easy - all we have to do is worry about ice, sleet, snow, shallow water and howlers. None of this corrosion stuff (Unless your boat is wintered next to a chemical factory on the south side of Chicago) and hurricane intimidation.
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I rebuilt my Commander rudder useing the original shafts. A blow
by blow account can be found in the archives in Jim Wiles-
"Let's talk rudders" thread. I built this trouble free(6 years and counting)
rudder for about three hundred dollars and a lot of head scratching,
without having to raise the boat. Check it out.
Cheers,B.
Commander#215
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On Hustler (Ariel #223), we replaced the rudder 2 times. The first time, we duplicated the original. We lost that rudder in medium air with the chute up. The second replacement was made from aluminum (may have been stainless-my brother-in-law handled getting it done) with the shaft and rudder welded together. This was done in 1994-1995 and is still holding together nicely. Designed the rudder to be narrower, not as tall, but a good 3 inches longer. Made the boat handle much better and took a lot of weight out of the back of the boat.
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Has anyone found a supplier for a exact replacement rudder head fitting?
I think that I have wear in the keyway that I would like to eliminate this season with the old rudder and defintely next season with the new rudder.
Jim
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That's one of those parts for which Rostand has the pattern. Still waiting for the patterns to be donated . . .
Keyway can be shimmed with paper thin brass sheet.
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Bill, My appologies, I should have remembered the posting speaking to the subject of Rostand.
The thin brass sheeting is a good idea to shim with. I'll keep that in mind. Also, a good source for that kind of thing ( thin brass, stainless, etc.) is model railroad scratchbuilding shops!
Another thing that I'm going to do is to mic both sides of my keyway; one side or the other could have worn out of tolerance and what I'm thinking of having done is to have some key stock specially machined to the measurements.
Thanks, Jim
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Of course, I cannot find the part laying around anywhere right now (and I did look a bit recently)...but I found a replacement head fitting for another guy's Triton in one of the area seajunk stores not too long ago...the part was cosmetically a bit different, but it worked fine on his boat. These parts were a pretty common size for the type of rudder setup, which was pretty common once upon a time. Might look around that way, too--I think it was less than 50 bucks for a real nice rudder head and the tiller fork to go with it.
Dave
