Rudder refurbishment

Maintenance and refit discussion
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Rudder refurbishment

Postby Chris » Sat Dec 07, 2013 2:23 pm

Last winter, while Impulse was ashore, I noticed water beginning to weep from an area in the middle of the rudder blade, at the base of the top tang. Not being particularly alarmed by this because I was aware of the construction of the rudder I decide I would make a temporary repair and tackle the issue the following winter and carried on with other 'maintenance' issues with the engine cooling system which I will cover in another post.
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The problem exposed in Spring 2013.
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When Impulse was hauled out in November the drip had become more noticeable and also there was play in the lower and upper bearing. So it was time to act.

I waisted no time in removing the rudder. Digging out the bearings and shaft nut was a rather brutal operation but because of the way the bearings and tangs are buried in putty, there is no other way.
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Eeek! is this really what I've got to do??
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Accepting this approach, it was actually a fairly easy task. Here is more information on HR's website:

http://www.hr-parts.com/contents/en-us/ ... 029-49.pdf.

Removing the rudder is one of those jobs where two pairs of hands make such a difference and I was fortunate to have welcome assistance from my brother.
As we dismantled the shaft we noticed the nut was only finger tight and this was the reason for the slack in the woodruff key on the tapered end of the shaft. It wasn't pulled up tight on the taper which was curious especially as the nut was buried in putty/filler so it couldn't have loosened on its own.
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Exposed shaft retaining nut (no split pin evident but there are holes in the shaft and nut)
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The easy bit is done!
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Once I got everything back to my workshop, I could see what needed to be done. I chiseled away the filler to expose the tangs of the lower bearing and its retaining screws and then the larger top tang in similar fashion. It was fairly well intrenched in a hard filler, certainly harder than I think intended by HR's description of 'putty'. There was also rubber mastic, Sikaflex I suspect, along the edge and behind the vertical face of the rudder and the bearing which was very difficult to dislodge. In the end I had to use an angle grinder fitted with a fine cutting disc, being extremely careful not to cut into the gelcoat.
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With the lower pintle now removed the poor fitting pin and bearing could be examined. After carefully measuring the diameter and trueness of the bore and pin, I was not convinced the movement was due to wear and wondered how good a fit the pin replaced last time was. I decided a new pin machined to the correct size may be all that was required. I am fortunate to have the means to cast bronze and a small engineering capability. I made a new pin and machined it to the exact size of the bore in the bearing. It fits perfectly and with the addition of grease nipples to both sections of the bearing (now used on other HR rudders) I think that will be all that is required for several more years service.

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As I have elected to refit the tangs so they will be visible, I had to improve their appearance somewhat. They had been rather brutally bludgeoned into the recess and hammer marks were evident. I would be interested to know if this was how Hallberg Rassy fitted them originally. I would like to think not . Fortunately they are sufficiently thick to remove a few thou' with a fan disk angle grinder and belt sander to bring them up to an acceptable finish. Straightening the tangs required some ingenuity and a two tonne press but fortunately the bronze is quite malleable. I will paint the exposed surfaces with a proprietary metal coating system and hard antifoul similar to the system I used last winter on the propellor and saildrive leg which has held up extremely well.
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The upper tang straightened and partially resurfaced. (It is just placed on top of the rudder for the photo)
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Once the area of the retaining screws has fully dried out, I will bore out large holes and insert threaded 316 stainless steel bushes and using countersunk machine screws, fix the tangs from both sides rather than having one bolt going right through and screwing into the minimal thread in the bronze as it was.
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A cross section of the intended fixing method when replacing the tangs.
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So that's how things stand so far.

I am waiting to see how dry I can get the area around the bolt holes which have been soaking in water for years probably. This is important so as to achieve a perfect bond between the bushes and the GRP which has been the weakness in the past. The other area that will require some careful consideration is the bond between the top of the rudder and the larger tang/bearing as pictured.
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Re: Rudder refurbishment

Postby Antti_DD » Sun Dec 08, 2013 11:03 am

Thanks Chris for a very thorough post on the subject. When our boat was hauled out in the Autumn 2011, I also noticed some cracks on the rudder. Those were located on the exactly same spots than those on your first photo. Unlike you, I was first quite alarmed about this finding, before I learned that the cracks are – at least according to the HR - mostly cosmetic and typical feature of basically all older HRs. The same goes with rudder weeping water long after the lift out, which is often referred as "Enderlein drip". I also talked about this with another 29 owner in our boatyard, and he had once repaired those cracks, but they had re-appeared after a couple of years.

When our boat was hauled out in the following year (Autumn 2012), there was a fairly large area on the bottom of the rudder blade, which stayed wet for weeks. We decided to tackle this by drilling drainage holes in the different parts of the rudder blade to let the water drain out.

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Water pooling in the lowest part of the rudder blade
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Drilling holes to the lowest part of the rudder
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I also contacted HR about this, and got a following guidelines from Magnus Rassy:

"It is not unnormal that there sometimes is water in a rudderblade. If it would be my boat, I would drill a drainage hole in the lower end to make sure that water is drained for the winter storage. I don’t believe in filling with epoxy. Once there has been seawater and salt inside it would no longer be a good adhesion. The core material is foam. There may be voids in the foam, but nothing to worry about." (According to the another e-mail from HR, the foam is polyurethane foam)

In general, I think that the rudder construction could be better, since these kind of problems are so common. However, the rudder is also very heavily build and firmly attached to the skeg. I have never heard of any rudder failure concerning an HR boat. Furthermore, water in the rudder is very common issue with boats, so I guess that the most problematic part is to get a strong but flexible bond between the metal and fiberglass.

Chris, now that you have basically dismantled the whole rudder, can you see how the water is getting inside the rudder blade. Is it via those screw holes for the 'upper tang'? If those would be sealed properly, could that prevent the water getting inside the rudder in the first place?

There is some play in the lower bearing of our rudder as well, but not so bad, that it would require fixing this year. Actually, there was a bit more play in our rudder, when I bought the boat, but I got rid of most of it by replacing the upper rudder shaft bearing in 2011. The new bearing was made by a local shop and cost about 20 €. HR parts and accessories also sells the whole replacement fitting at a price of about 180 €.

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"Upper rudder shaft bearing"
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Antti Laine, Forum Administrator
HR 29 # 483 "Dolphin Dance"
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Re: Rudder refurbishment

Postby Martijn » Sun Dec 08, 2013 11:26 am

Hi there Chris, thanks so much for posting this topic , this subject is already on my list from the beginning but have not yet actioned it. The banging noise in the lower bearing is becoming so bad that fisherman complain they cannot catch anything whem I'm passing with QUINT. I have the exact same issue with the leakage too. HR, Annti and others have detailed on the rudder replacement job but this level of detail will make life really easy. I will for sure start up the process and update on my progressions.... thanks again!!

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Re: Rudder refurbishment

Postby Chris » Sun Dec 08, 2013 12:15 pm

Hi Martin,

I think we all owe Antti a debt of gratitude with his efforts on getting the HR 29 forum up and running. It will surely be a great watering-hole for all of us who maintain our own boats. Hopefully their well be a great exchange of hard won knowledge and experience.

Hilarious way of describing the defect in your rudder. The great thing about these rudders is that whilst it has its problems, the fundamental engineering is really bullet-proof and is highly unlikely to ever fail. The movement in mine was just annoying and the drip when Impulse is out of the water unsightly. I just believe in the saying 'A stitch in time saves nine'.

As I said I will update the article as I progress, I will also include failures, mistakes and any changes I make, as these I believe are also of value.

Is it something you are considering doing over this winter?

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Re: Rudder refurbishment

Postby Chris » Sun Dec 08, 2013 12:35 pm

Antti,

The water is most likely getting in through the bolt/screw holes in both the upper tang and the lower bearing/pintle (Not really sure what the parts are called). In the picture of the lower bearing which I took immediately after I had taken it apart, you can see how wet and muddy it was behind the bronze. This was buried in filler. That's why I have considered changing the method of fixing by trying to make a seal between the GRP and the bolt/screws. If it at least had some sort of sleeve to stop the thread of a bolt or screw cutting or wearing into the GRP. I have had tissue pushed into these holes since removing the rudder and at first the tissue was quite wet. It is now slightly damp after being in place for 24hrs. So I am hoping it is drying and a moisture is fairly localised. The GRP appears solid in this area but I suppose it could find its way through the laminate in time into the blade itself. I'm hoping mine is dry but that might be being optimistic. My brother has a moisture meter which I will borrow to test the rest of the rudder.

Yes, HR parts are pricey. I hope to be saving a few pounds in what I am undertaking.

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Re: Rudder refurbishment

Postby Tarka Dubh » Fri Dec 20, 2013 9:55 pm

Chris,
Thanks for the write up, which is very interesting. I had to go through the same process a couple of years ago and had great difficulty getting the rudder stock separated from the top of the rudder. In the end I made a puller which, combined with a club hammer and blow torch, eventually did the job. I had the bottom fittings re-machined and a new pin made. The top bearing was also replaced, but did not really need it. I reckon much of the wear occurs when the boat is left on the mooring and the rudder is constantly moving slightly as boats go past. I now make sure the tiller is securely lashed when left. In hindsight, I wish I had fitted grease nipples. Maybe I could retrofit them, although I guess the swarf from the drill would get into the bearing.

One point worth mentioning: I noticed that the fittings had slight dezincification as they were a little pink. I think this was only on the surface, but as a precaution, I have fitted small anodes. I don't know if this is strictly necessary, but they are mostly gone by the end of the season. I have also seen an HR29 based in Weymouth (Carpe Diem) which has anodes fitted. Luckily, the bronze fittings are quite substantial, so I don't think it's a significant issue.

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Re: Rudder refurbishment

Postby Chris » Fri Dec 20, 2013 11:14 pm

Hi and welcome.

Yes, I am learning this is an issue common with this marque of HR. But fortunately all repairable. The grease nipple idea just seemed to make sense to me which was confirmed when I saw it mentioned on the HR site that they are fitted to more recent designs.

I suppose the tangs on Tarka Dubh have been covered in filler again which would make removing the rudder a pain. Although with some extremely careful drilling and tapping it may be possible to retro fit.

The bronze at that point on the lower bearing is 15mm thick, plenty for a grease nipple. I intend recessing them.

I don't think the pinkish colour is dezincification, but from my bead blaster. For some reason this seams to happen sometimes. As you say though the bronze bits really are pretty substantial. Interesting info about the anodes though.

Parting the top bearing form the rudder stock could be potentially problematic. I made some steel wedge-shaped drifts as shown in the step by step which Antti kindly passed on to me. They were very effective and not particularly aggressive.

When you say you replaced the top bearing was that the one that fits on to the rudder with the long tangs? I understand all the parts including the rudder blade are still available from HR. Was the replacement from them or did you find someone to make it for you?

It's certainly great to have the forum to exchange ideas and views.

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Re: Rudder refurbishment

Postby Tarka Dubh » Sun Dec 22, 2013 12:09 pm

The bearing I had made was the plastic one at the top of the rudder stock. All The work on the rudder/bearings was seven years ago and I'm pleased to say that so far there is no play in either of them. I also fitted rubber blocks to the steel rudder stops, which absorb most of the shock load if you accidentally lose your grip on the tiller when reversing; the force when this happens can be alarming!

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Re: Rudder refurbishment

Postby Chris » Sun Dec 22, 2013 11:22 pm

I know the one you mean now. Phew! for a minute I thought you meant the top bearing on the rudder blade. With its tapered fitting and weighty size it would cost a small fortune I would think.

Great idea about the rubber stops, as that very same manoeuvre has caught me out but I ended up being the stop!

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Re: Rudder refurbishment

Postby Chris » Tue Dec 31, 2013 3:11 pm

A little more progress with the rudder.

I decided to strip the rudder right back. As the area I was trying to repair was getting bigger and bigger. Trying to bond new material to unknown substrate is a risk not worth taking. There was the coppercoat and then primers beneath that. It is all now polyester based substrate.

There were a few areas of dampness confined to the areas around 2 or 3 of the bolt holes where I was getting readings of around 15 to 20% but these readings tailed off to around 5% only a few millimetres from the holes. The rest of the blade is reading below 5% but most areas retuning 0%.

So I am quite happy to start proceeding with repairing the blade

I am not sure whether there is a difference between the rudders on the 29 and the 312 but on mine the long tang is stamped 312! There is a disparity between the space between the tang arms and the thickness of the rudder recess of about 12mm. Rather than make this difference up by bodging it with filler which actually absorbs water, I will laminate and gelcoat the recess to the correct thickness and shape at the same time bonding in the bushes for the tang screws making it an accurate fit.

To stop any water ingress behind the tangs, a small fillet of rubber sealant will be applied between the rudder and the edges of the tang.

After various minor laminate repairs I will re-coat the whole blade with a 2mm thickness of white gelcoat filling and sanding the various irregularities discovered during the stripping process.
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Stripped rudder
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I have now machined in the grease nipples into the lower pintle. The pictures show that this should allow annual re-greasing of this bearing.
GN1.jpg
Boring and tapping
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grease nipple in place
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Filling with grease
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Protection cap fitted
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