Foolish Muse
Well-Known Member
What??? This is Victoria. The best sailing and racing is in the winter.
Building a rudder - materials advice?
- Thread starter Foolish Muse
- Start date
What??? This is Victoria. The best sailing and racing is in the winter.
Kukri
Well-Known Member
I still think that in your case, with a ULDB type boat, carbon fibre will be the best way to go, if the Class Rules permit it. Buy the tube for the rudder stock, and the rest you can do yourself.
BobPrell
Well-Known Member
Yeah Stainless Steel, what I usually call Alleged Stainless Steel, seems to be something that on occasion, fails catastrophically. From what I have been told about it, burying it in resin is just what can cause failure.
Carbon fibre can fail too. Do we just ask too much of these materials? I think yes but I don't expect fans of high-performance as an end in itself to change anytime soon.
vyv_cox
Well-Known Member
I think you will find that that particular rudder stock was made from aluminium, the cause of failure being mostly corrosion. The case you talk about is on the Elan 333, where the stainless steel stock had a change of section to something smaller in the lower part, glassed over. The stock failed in fatigue, not because it was stainless steel nor because it was buried in GRP. It failed due to poor design, which would have happened in carbon or alloy steel, or almost any other metal. The covering of GRP prevented inspection, by which a crack might have been picked up beforehand.
Joker
Well-Known Member
Not aluminium but stainless steel.
Triassic
Well-Known Member
As a matter of interest Minn how would you engineer/manage the bearing surface between the carbon stock and the rudder tube? I don't know what the Olson has fitted but it's going to be something designed to work with the standard stainless stock.
DownWest
Well-Known Member
I would stay away from carbon and stick with the stainless shaft. The rest of the rudder is just a profile on the shaft and it's welded on framework.
The slight difference in weight is not a big issue, esp as you are not conversant with the carbon, which needs a lot of experience in fabricating.
The slight difference in weight is not a big issue, esp as you are not conversant with the carbon, which needs a lot of experience in fabricating.
vyv_cox
Well-Known Member
Your blog, which I checked before I posted my comment, says 'The picture on the left shows the groove that the bearings have worn into the aluminium. The middle one shows the corrosion of the aluminium by the upper tang. The right-hand photograph is where the tang has come away completely, either due to corrosion or poor welding in the first place.'
Joker
Well-Known Member
Quite right. Because the rudder was such a mess, I had it rebuilt. Since the aluminium stock, as you can see, was in a dreadful state, I had it replaced by a stainless steel stock. It is the stainless steel one which failed.
vyv_cox
Well-Known Member
Any details, photos? Are they in your blog?
Joker
Well-Known Member
Yes.
