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Rudder Stock

Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 300 / 301
Forum Description: 300 & 301 Hints and Tips
URL: https://www.myhanse.com/forum_posts.asp?TID=9117
Printed Date: 28 March 2024 at 14:30
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com


Topic: Rudder Stock
Posted By: graeme
Subject: Rudder Stock
Date Posted: 06 July 2015 at 21:11
Hi - long time no post. Sadly, long time no sail.

I need some advice to avoid a £2000 bill that I don't really understand. The work has not started, so looking for options - urgently.

When I bought my 301 the rudder bearings were showing play, so I got a local company to replace the bearings while she was on the hard. They made their own and all was well. No play.

Fast forward 4 trouble-free years, but not been out of the marina for the last 9 months and when she came out the water, the rudder was stuck solid. Tried everything, but nothing budged. When inspected the only anomaly was  the rudder "tube" that the stock sits in, was filled with what I assume to be rain water coming from above. The stern locker floor was dry.

After drying for a couple of days, 2 of us eventually got it moving slowly and the water started to drain as we rocked the rudder back and forth. However, it was still very very hard to turn - impossible for one from the rudder, and even the extra lever of the tiller took both arms.

If freedom of turning the rudder is a scale from 1 to 10, with 10 being totally seized - it was an 8 or a 9.

My theory is the bearings from 5 years back caused the problem. But dunno. The company involved 5 years ago is now gone, so asked another company to diagnose.

They dropped the rudder and say the stock is extremely pitted half way up and reckon it is too suspect and may fracture when it is doing its day job at sea. So, they are suggesting a minimum £2000 to replace and re-fit rudder - and imply a lot of hard work refitting the rudder to the stock.

I have yet to see it for my own eyes - will do in next few days.

Is there a way to replace / repair a stock that is not so traumatic to my wallet ?

Is this a design / Hanse thing or am I just unlucky ?

A problem shared......

Thanks

Graeme




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Hanse 301 - Deep Fin - MD2010 - MS25S - 2001



Replies:
Posted By: nickflo
Date Posted: 06 July 2015 at 23:53
I believe that you have a Jefa rudder. Just call Jefa I'll be sure they can help you or can give a tip.

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S/Y Druid

Hanse 342 #555

Kiel, Germany


Posted By: Bitbaltic
Date Posted: 07 July 2015 at 09:29
Hi Graeme,

This is a common problem with the 301 (ask me how I know). When I bought mine 3 years ago the rudder was very stiff and the surveyor suggested replacing the bearings. When the yard dropped the rudder to investigate it was found that a) the aluminium stock was badly pitted and b) someone had tried to remediate this by filling the pits with epoxy.

The epoxy repair had disintegrated and the bearings had then seized. quite a mess as both bearings and stock were then damaged.

I have since heard anecdotal evidence of this happening on several other 301s and some of the earlier Judel/Vroljik Hanses. The causes of the problem are not certain- the pitting may be due to some sort of crevice corrosion when the rudder stock is in contact with the bearings, and my yard were of the opinion that the aluminium stock itself was not of sufficient grade.

Re. the rudder. The first thing my yard did was contact Hanse to try and source a replacement. Hanse seemed confused and eventually sent a drawing of a dissimilar rudder. I think this may have been a consequence of different rudder designs (at least some of the time) being fitted to the wing and deep fin versions of the yacht (mine is a wing keel with the rudder blade squared off at the tip; a fin keel 301 in the same marina has a perhaps longer rudder blade with a distinctly rounded tip).

There is some doubt as to whether or not the rudder is a Jefa- I have heard suggestions both ways and when I looked into it a couple of years ago (can't remember the details now) I concluded that (at least for the wing keel version) the rudder was probably not a Jefa.

Re. way forward. Whether or not the original rudder is a Jefa, I would suggest you contact them in the first instance as they are the only likely source of a direct replacement. If Hanse themselves could supply anything at all then I suspect they would try to source it from Jefa anyway. If Jefa are confident they can help you I would go that way as the other option is a lot of effort....

If you get no luck from Jefa then your only choice will be to rebuild the rudder completely. This is what I ended up doing, as at the time I did not know about Jefa as a potential source of a replacement.

The yard split the GRP rudder 'shell' in two, removed the stock and tangs, and cleaned out the foam core. They then fabricated a new stock from top-quality marine grade aluminium, re-attached the tangs, re-bedded the stock in the shell and glassed the blade back up. They also replaced the bearings with newly fabricated units.

The end result was excellent and there have been no problems in the three years since (I had the rudder unshipped last season in order to make a long-term check).

But : the process took 2-3 months (including the time spent waiting for info from Hanse) and the final cost was somewhere in the region of £2500 for the rudder repair and more for the bearings.

I don't seem to have the pictures of the stock pitting anymore, it would have been nice to have attached them.

Good luck whatever you choose to do. If you would like to discuss or perhaps put your yard in touch with one that has done this before feel free to pm me.

Cheers

Huw


Posted By: graeme
Date Posted: 07 July 2015 at 23:36
Nick(?), Huw,

Great info from both - thanks - which led me to contact the UK Jefa disti. 

I have yet to confirm price and availability, but thought I'd post the drawing they sent me "for the record" on the forum.

uploads/3133/Hanse_301_Replacement_Rudder.pdf" rel="nofollow - uploads/3133/Hanse_301_Replacement_Rudder.pdf

Graeme


Posted By: samuel
Date Posted: 08 July 2015 at 15:47
Are the bearings roller bearings or nylon bushes. Nylon swells in water
As for new rudder, i would definitely go for jefa, not a one off job.
Having seen my 311 rudder when it failed i would be wary of a hanse rudder that was not jefa

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Daydream Believer- Hanse 311- No GBR9917T- Bradwell Essex


Posted By: graeme
Date Posted: 29 July 2015 at 00:43
For the record, below are some pics of the problem rudder shaft, highlighting examples of the pitting. The pitting does not look as extreme in the pics as in the flesh.

Bottom line....... there is no way I could this back on my boat.....not after seeing it.






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Hanse 301 - Deep Fin - MD2010 - MS25S - 2001


Posted By: Lippe
Date Posted: 29 July 2015 at 17:09
I may also have some pitting like this but do not consider it very dramatic.


Posted By: Gregor
Date Posted: 30 July 2015 at 15:12
Had the same and filled them with epoxy. Flinting afterwards to the degree it fits in the bearing again.

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Uisge Beatha

Currently sailing Dehler 36 JV (2002)
Previous boat: Hanse 311 #80

http://www.uisge-beatha.eu" rel="nofollow - http://www.uisge-beatha.eu


Posted By: samuel
Date Posted: 30 July 2015 at 20:45
Rather than fill with epoxy, which would give no structural strength, why not weld the crevices. This would fill the voids with molten metal which would form part of the main shaft. It could then be ground flush again


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Daydream Believer- Hanse 311- No GBR9917T- Bradwell Essex


Posted By: Bitbaltic
Date Posted: 30 July 2015 at 21:18
Originally posted by Gregor Gregor wrote:

Had the same and filled them with epoxy. Flinting afterwards to the degree it fits in the bearing again.


As I mention in a post above when I purchased my boat I discovered it had pits in the stock which had been filled with epoxy. Whilst this probably worked for a previous owner in the short term, in the long term it resulted in the disintegration of the epoxy and damage to the bearings.

I can't comment on Samuel's idea of welding these pits but epoxying them up is not likely to be a good long-term idea as it only defers a bigger repair bill.


Posted By: graeme
Date Posted: 30 July 2015 at 23:01
I also consider what can't be seen. The pitting doesn't stop at a clear line, it continues under the rudder. I have no idea what it is like "below the surface". Better or worse, no idea.

Also.....the worst area we can see, just so happens to be the point of most stress. Epoxy would make it smooth - not sure what else.. I used to fill pits in motorbike forks, but that was just to ensure a hydraulic seal, and the pits were small.

The material chosen for this rudder is just not fit for purpose - these are big pits caused by just sea water and whether welded or epoxied, the corrosion will just pop up elsewhere. 

One analogy that rattles in my head : if i knew an alloy wheel had a fracture on my car, but still retained structural integrity and was drivable, would I be happy driving up 400 miles up to Scotland with my kid in the car. Simple answer, is no. 

Life at sea is stressful enough, without having doubts about something so important. I don't want to worry about the hull, the rudder or the mast. 

To be frank - this is a question of money too. If I did not have an emergency fund or if I had lost my job, then my decision may have been different. 

I will just pay up, replace and be worry free...... until, inevitably, the next boaty issue pops up, then I'll start another thread............



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Hanse 301 - Deep Fin - MD2010 - MS25S - 2001


Posted By: perry
Date Posted: 02 December 2015 at 19:14
I also have a Hanse 301 [built 2001] with semi siezed rudder Stock. There is nothing worse  than sailing with lack of feel with a tight rudder stock.
The use of aluminium for a rudder stock is very very bad design and incorrect choice of materials.
Marine grade Aluminium maybe fine for immersion but not immersion and wear.
The only material for such sea water immersion and wear is Monel. I have a 30 year old yacht with Monel Stock and its as good now as when new.
Logical solution cut round the Rudder fibre glass shell split remove the Aluminium stock and make new stock in Monel: Glass back up. Also add a bit of extra area 301 is under ruddered. Cost should be less than half new Aluminium stocked rudder from Denmark and it will outlast the owner.


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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: SausalitoDave
Date Posted: 03 December 2015 at 15:44
I can't tell for sure from the picture; however, the pitting looks minor. I would TIG weld any pits more than a couple of inches from the rudder. Closer, may cause heat damage. I suggest the only problem may be stress concentration. The depth of the damage looks very small. I would polish anything I could not weld to reduce stress concentration. Not sure what an epoxy fill would accomplish. As the epoxy falls out, as it will, it will contaminate the lower bearing. Talk to a talented TIG shop. Aluminum is super easy to fill weld.

Dave


Posted By: perry
Date Posted: 04 December 2015 at 08:26
I dont think TIG welding this grade of marine Aluminium is a good idea: here is some advice from the Aalco website:-
http://www.azom.com/ads/abmc.aspx?b=2745" rel="nofollow - Aluminium alloy 6082 has very good weldability but strength is lowered in the weld zone. When welded to itself, alloy 4043 wire is recommended. If welding http://www.azom.com/ads/abmc.aspx?b=2745" rel="nofollow - Aluminium alloy 6082 to 7005, then the wire used should be alloy 5356.

Note:- The corrosion resistance of Aluminium alloys comes from their oxide film. When used in a rudder stock the oxide is worn off repeatedly and corrosion takes place causing the bearing to tighten. Totally incorrect design! and material choice.
A Solution?  cut round the rudder moulding part the halves, remove stock re-maufacture in Monel or maybe Stainless 316L. Make plain bearings from Delrin using a bearing clearance on rudder stock of 0.1-0.2mm. And with 1-2 mm clearance between outer diameter of Delrin bearing and inner diameter of bearing sleeve in yachtand 'Float' in the lower bearing with Adhesive sealant like Sikaflx 292. That way the alignment problems are allowed for.


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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: SausalitoDave
Date Posted: 04 December 2015 at 15:05
Perry:

You are absolutely correct about the Al-oxide coating creating much of its resistance to oxidation, I had not thought about that.  Wear at the bearings will obviously have an impact on service life.  I still don't think there would be a problem welding up the small pitted areas as that process should not heat up the entire shaft.  Monel is a novel idea; however, if you are going to the effort of re-building the rudder, why not just use 316L?  It is stronger and easier to weld and machine.  


Posted By: perry
Date Posted: 04 December 2015 at 16:50
I have owned my current Bolero for 30 yrs and original stock is Monel, only one change of Delrin bushes. Rudder shaft is like new. David Thomas designed her, and he had experience in marine engineering [big ship] to add to his undoubted ability as a yacht designer.

Ok 316L should do, but I have seen 316L component in a submarine which corroded [disolved would be more accurate]  because immersed in a small pocket of sea water with no oxygen. The submarine problem was cured with a Hastalloy 276 I think?
I havent checked price on Monel, I know its much more expensive than stainless.

So when I make new stock for my new Hanse 304 rudder from 304L [which I just happen to have a length] I intend to epoxy the shaft and particularly the tang joints to try and stop contact with cells of sea water should the rudder leak,  which they usually do.


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Current Yacht Hanse 315 2007
Last Yacht Hanse 301 Round GB in 2017


Posted By: samuel
Date Posted: 04 December 2015 at 17:13
Any salt water that gets into the rudder will cause pitting of the monel quite quickly, as it m ight in the bearing area just above the bottom bearing. One also needs to consider the electrolytic action with things like an aluminium saildrive. One might find anodes being eaten very fast.

If you look at the Jefa website you may find the video of how a rudder blade is made & foam filled. I doubt that ,with all the best will in the world, a home made rudder blade, bodged from the old blade,  will have the same quality. My old blade split in 2 parts & one vertical side went drift about. Having seen how poorly it was made I feel somewhat glad I lost it & obtained a Jefa one

The bearings have not been a problem for me - I used jefa roller bearings & fitted new rollers when I changed the rudder after my boat was 12 years old.

There was limited pitting to the shaft but not in the area of the bearing - which was perfect- but just above the top of the blade- possibly due to over enthusiastic antifoul application. Jefa say that the stock is well over designed to allow for this

I think Jefa have made enough rudders to know how to do it by now . I suspect that your Hanse has a blade made from an earlier supplier & if it was like mine then it is carp.

But to each his own & if it works for you then great


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Daydream Believer- Hanse 311- No GBR9917T- Bradwell Essex



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