Jaguar 27 rudder construction

[MikeBz]

Does anyone have direct knowledge of the rudder construction on a Jaguar 27? My brother-in-law is looking to buy one, however the survey has suggested that the rudder is wet inside.

The vendor's agent has said "My personal advice is that all GRP rudders on used boats are wet internally which the survey could or should have pointed out. Rudder construction is in two halves normally bonded together and with a foam or polystyrene filling. There appears to be no join on Xxxxxxx rudder and I am wondering whether the rudder has been previously repaired. The rudder construction appears to be sound and I think the surveyor is being a little harsh on this point."

My inexpert view would be that is it's a closed cell foam then it doesn't matter too much if the foam itself is wet, but if it's open cell or there are materials in there which will corrode or rot (steel, aluminium, wood) then you do not want water in there.

Mike

 

[johnlilley]

On nearly every GRP vessel with a GRP rudder of any age the likelihood is that the rudder will have high moisture levels or be waterlogged. Although some builders built their rudders not expecting them to leak & used inferior materials such as mild steel internal metalwork, they ultimately did/do leak with obvious consequences to some in that the rudder becomes disconnected from the rudder stock because of corrosion.
If the rudder has used good quality internals such as stainless tangs welded to stainless stock then a waterlogged rudder is of no concern other than it can go on to blister because of chemical reactions occurring when the foam (if foam filled) breaks down & this can be a messy job to sort out but unless it is catastrophic, it should not be a major structural problem.
The checking of the internals is the main cause for concern & price reduction as these can be at risk if the detail of build is unknown. The surveyor is correct in giving the information but generally it would also have to be qualified in my opinion with the additional information above. Far to easy to pick up problems but not explain the problem, although in this case perhaps the surveyor has explained, we do not know at this time.
The only other problem is that the two halves can start to separate as the method of joining was a bit weak in some cases but this is usually easily seen & easily rectified required.. The best idea is to construct a rudder knowing it will water log eventually and build it accordingly.

John Lilley

 

[MikeBz]

Thank you John, so I guess in this case the issue is are there steel internals and if so what is their lifespan expected to be once the rudder has taken on water. Any Jag 27 experts on the forum?

 

[Blueboatman]

May I suggest..Use a big magnet?
But practise first on other stainless steel fittings like the rudder shaft top, and with a wood 'spacer' to simulate the depth that any rudder metalwork is buried inside the rudder casings thickness ..
Stainless steel can be mildly magnetic.
But mild steel may well really 'pull' that magnet hard to the rudder shell, the trick is to be confident enough to decide which is likeliest !

Or, locate the tangs by tapping drilling g or magnet and then drill a sample of metal shavings...

 

[johnlilley]

Some indicators of problems internally can be rust staining emanating from any low breaches in the rudder or staining leaking from the joints of the two halves or perhaps drill a small hole of no consequence an see what leaks out, but Blueboatman's tips should work. Once seawater has come into contact with mild steel tangs the life is definitely limited but totally unpredictable as it depends if the internal laminates have effectively sealed the welds or connection to the stock.

John Lilley

 

[oldsaltoz]

Hi Mike,

The simple test is to drill a 6 mm hole up from the bottom and if no water try a couple more about one third the way up from the bottom. Catch the material that drill removes and have a good look atm dry it with some heat and check again, it be quite different when dried out depending on what type of foam was used if any.

Being only 6 mm holes they are very easy to plug with a dab of Araldite if you have no epoxy resin to hand.

It's worth noting that very few if any of the major boat builders actually build there own rudders, it contracted out to others who specialise in this area and are tooled up to make hundreds of them.

The real problem is that you ever get to the outer skin and can only hope it was in fact built to specification and design.

I have built,repaired modified many rudders over the years and common failures are mild steel used, or stainless welding that not properly pickled (if at all) resulting in tangs breaking off the stock, also a lack of bracing with gussets each side of the tangs rather than a simple butt weld.

Many or poorly designed with little or no sacrificial sections at the top and bottom ends, to allow a section to break off rather than destroy the structure.

I started using 'O' rings on the top end of the rudder stock to ensure a proper watertight seal, fully enclosed in the structure and none of them ever developed a shaft leak. the cost is about 10 minutes and two bob for parts.

The other built in problem is that some manufacturers do not brace the gap between the tangs and the rudder skin, so the foam eventually compresses and you have a lot of play in the steering. The simple fix it add some Micro-fibres between the tangs and the outer skin. Again not at all expensive.

I apologise for the long post, but half baked rudder manufactures should be put named and shamed. Or at least be on a boat in bad weather when the rudder fails and see if that makes them proud of their workmanship.

Good luck and fair winds.

 

[Ruffles]

Surely if all fibreglass rudders were waterlogged they would burst when they froze on the hard in Winter?

 

[Blueboatman]

Some indicators of problems internally can be rust staining emanating from any low breaches in the rudder or staining leaking from the joints of the two halves or perhaps drill a small hole of no consequence an see what leaks out, but Blueboatman's tips should work. Once seawater has come into contact with mild steel tangs the life is definitely limited but totally unpredictable as it depends if the internal laminates have effectively sealed the welds or connection to the stock.

John Lilley

Confession time.
My Corribee rudder failed and simply spun on its stock one day. Ha, ses I, that be the mild steel pins driven through the stock. Newbridge yachts quality c1980 had 'variance' so I was expecting it.And years previously had drilled a 30mm hole through the aft edge to quickly secure a paired steering rope, in the event..

But, by now I was in the Caribbean , no tides, cue cheapo haul out on a forklift, time to a/foul anyway..
I split the rudder casing open. You may guess .. The bronze pins were sound as a pound .
But years earlier in an attempt to remove the tiller yoke I had removed the securing bolt( Skeg rudder so no risk of loss) and drilled a hole in the tiller yoke and rammed penetrati g oil in there...
So, years later, the yoke finally released and the tiller, not the rudder blade, span on its axis.. Ahem

Note to self: if I had carried a strong magnet!

 

[essexboy]

You might try CYB which if I recall was Canvey Yacht Builders, the Builders. Whilst the are into more mundane things like fibreglass roofing now, I think the boss is one of the original team and may be able to help. They also do a rather good weekend course on Fibreglass work.

 

[PetiteFleur]

Go to the Jaguar 27 owners association jaguaryachts.co.uk you'll get an answer, they are very helpful - my previous yacht was a Jaguar 27. Excellent boat, I loved it and went all over the East Coast, France, Belgium & Holland. No problems with the rudder though and no idea of the construction.
My friends boat, a Contessa 28, lost her rudder last year and this was 3 months after being surveyed!

 

[oldsaltoz]

Surely if all fibreglass rudders were waterlogged they would burst when they froze on the hard in Winter?

Not common, the foam crushed as the ice expands.

 

[MikeBz]

Lots of useful info, thankyou folks. I found an archive with a load of Jaguar info here: http://myweb.tiscali.co.uk/westgatefamily/archive3.htm#

 

[cliff]

Thank you John, so I guess in this case the issue is are there steel internals and if so what is their lifespan expected to be once the rudder has taken on water. Any Jag 27 experts on the forum?

Yes. I made a replacement rudder for my old Jaguar 27

 

[cliff]

Forget the "opinions" expressed above.
The rudder stock is Stainless steel to which is welded a stainless steel plate - NOT tangs but a plate ~18" long by ~6" deep by ½" thick.
Remove the rudder from the boat. You will need somewhere to work at it warm and dry.
First make a full size drawing of the rudder and shaft carefully marking the end of the shaft, the location of the top of the rudder blade and the profile of the rudder.
Carefully cut round the rudder and remove the fiberglass shell and all the old foam core. Clean the shaft and plate carefully and place over the drawing made earlier - you now have the templates measurements needed to prepare new closed cell foam filler.
Central sheet ½" thick shaped to the profile of the old rudder and cut out to allow the stock and blade to be inserted. Add two outer core sheets ¾" thick shaped to the profile of the rudder. Note: a recess will need formed in these sheets to accommodate the shaft. Mark the sheets and with the aid of a suitably sized socked and a hammer make the recess(s) by crushing the foam.
Now for assembly - I used polyester resin initially to bond one outer core piece to the stock and plate ensurein proper alignment of the shaft in respect to the finished profile hence the importance of an accurate drawing.
Next was to fix the ½" central core piece over the rudder plate and bond to the first piece and the plate. At this stage I drilled through (IIRC) 6 holes already existing in the plate out through the first core piece fitted. Finally the remaining outer core piece was fitted and again bonded with poly resin. and the 6 through holes drilled through the last core piece. Weights were placed on teh sandwich and the resin allowed to harden overnight.
Now comes the fun part - shaping the blade - I used an air driven DA sander for roughing out the profile and finished off with a sanding block. Warning: the closed cell foam sands very easily. By laying out contour lines you can achieve a slimline, smooth profile tapering to almost nothing at the trailing edge and nicely rounded / tapered on the leading edge.
Once you are happy with the profile you can start glassing it up. First I threaded resin impregnated tape through the holes in the blade and splayed the ends out over the surface - this was to help hold teh outed surfaces of the shell together and give the finished rudder more rigidity.
Initial layups were poly resin over woven rovin (woven glass mat) rolled to exclude air pockets - do invest in the grooved rolling tool - you can get a very high glass to resin ratio and a very strong job. After around6 layers I changed to epoxy resin and non bonded mat and Kevlar tape for the leading, under and trailing edge of the rudder tape Another 6 layers resulted in a shell about 1/8" thick.
Finla touch was to fit 3 "O" rings around the shaft at the top edge of the rudder blade, coat them with a thin fils of grease and glass them into the top of the blade to give a seal and prevent water leaking in down the shaft. A final sanding / polishing and it is ready to refit and antifoul.
Trust the above is clear

 

[MikeBz]

Wow, very comprehensive thanks Cliff.

There are quite a few posts in the archived Jaguar forums which talk about rudders with mild steel shaft & tangs - is it possible that the rudder construction changed over time? I think a few boats had transom-hung rudders but not the one in question which has a spade rudder and is of 1971 vintage.

Mike

 

[cliff]

Wow, very comprehensive thanks Cliff.

There are quite a few posts in the archived Jaguar forums which talk about rudders with mild steel shaft & tangs - is it possible that the rudder construction changed over time? I think a few boats had transom-hung rudders but not the one in question which has a spade rudder and is of 1971 vintage.

Mike

Sorry. I assumed you were talking spade rudder - stainless shaft and plate AFAIK - mine was 73 vintage. Transom mounted were a bit of a dogs breakfast with mild steel fittings etc.

 

[Laurie]

I set up and ran the JOA for years. The rudder is a sandwich GRP construction, some have all sorts of " stuff" therein, and some none, as it should be. Some rudders are swept blades with the tangs internal and these can be more vulnerable to rot. The transom hung variant on the J27 is more robust as the tangs are external and clamp the blade. Mine was the latter and used to get water ingress which was not then a major issue.
Splitting and rebuilding is the only sure fire remedy for any blade with internal tangs (most). I have drawings/dimensions for the J 27 blade if you wish (email me on laurie@lmilton.co.uk) as I can't upload images here........