chainplate hump

[ronassis]

Hi this is a first post for me. I have 2004 Jeanneau 32 yacht on which I have just noticed a slight hump in the deck around the starboard chainplate. I suspect water ingress into the pad underneath. I can access it from inside the boat and will remove the lining in that area to have a better look next week . Anybody with any experiences of this in any of your boats. If the plypad has delaminated will I be able to replace it myself or will it be expensive?
Thanks Ron

 

[Tranona]

That does not sound quite right. It is unusual for a chain plate on a modern boat to be just attached through the deck with a ply pad underneath. More usually it will be to a bulkhead or with a tie bar down to a structural part of the boat. The chain plate may well pass through the deck and water can get in if the sealing fails. This may lead to water getting into the core if it is a cored deck. A bit more investigation needed to find out exactly how it is constructed before deciding if there is a problem and how to deal with it.

 

[pvb]

Hi this is a first post for me. I have 2004 Jeanneau 32 yacht on which I have just noticed a slight hump in the deck around the starboard chainplate. I suspect water ingress into the pad underneath. I can access it from inside the boat and will remove the lining in that area to have a better look next week . Anybody with any experiences of this in any of your boats. If the plypad has delaminated will I be able to replace it myself or will it be expensive?

Welcome to the forums! As the integrity of the chainplate is rather important, it might be worth asking a surveyor to give you his opinion on the best course of action.

 

[Concerto]

On my Westerly Fulmar, I have a similar problem with the deck lifting around the shroud plates. The surveyor siad it was a common problem on early Fulmars and was due to a misalignment of the tie bar. He checked the moisture levels in the general area and they were normal. The problem is solveable by inserting a large stainless steel plate uner the deck and having the tie bar shortened. However he also said it had been fine for 33 years and would pobably be fine for the next 33 years. His advice was to leave well alone as there was no leak.

 

[William_H]

The hump is obviously a falure of the structure to carry the chain plate loads through to the hull and ultimately the keel. As said you need to investiget the cause of the failure.
I suggest it might be caused by people applying too much static load to rigging over a long period of time. (that is my own theory and my be wrong but is evident in wooden boats)
I like the idea of attaching a metal or wire strop to the under side of the chain plate which goes down to further attachment on the hull (or bulk head). If there is a screw adjustment bolts or turnscrew you can apply static load to pull the deck bulge down and positively transfer load from chain plate down to the hull. An SS plate can be bonded to the iside of the hull put lots of holes in it for resin to pass through the plate and use epoxy. Sorry I don't know the boat and so your investigation will be most important.
good luck with the repairs olewill

 

[Plevier]

I had a 2003 Sun Odyssey 32, I expect the 2004 is the same.
The shrouds go to U bolts through the deck just inside the toe rail. Comments about chainplates and tie bars are misplaced in this instance.
You cannot see from inside the boat what strengthening there is (and i always wondered!) - I don't know if the OP has any specific information that it's a ply pad?
I would want to know what there is before diving in. A Jeanneau dealer should be able to help, they should have drawings on their computerised system, alternatively I actually found Jeanneau quite helpful when I emailed them with a technical query about mine, worth a try.

(Edit - if it's a SunFast not Sun Odyssey it's different, shrouds are in the middle of the side deck and there is a tie bar inside.)

 

[oldsaltoz]

What sort of surveyor would say " it's benn ok for 33 years so should be ok for another"?

When the truth is, it's been ok for 33 years but it's now failing adn should be properly investigated and repaired before it fail completely.

You could do the initial investigation yourself as it's mostly just getting access to see what may have caused the problem.

If it is a misalignment of the below deck section, it's shoddy workmanship in the original build.

The fix is not rocket science, just a realignment and a bit of epoxy and cloth.

Good luck and fair winds.

 

[JonJon]

Yes I have exactly the same problem with my portside forward lower which attaches in the middle of the side deck. I believe the shroud must have had a whack with something in the past probably a spinnaker pole. Its a Sun Fizz 40 -the attachment under the deck is just two nuts on the fitting with tiny steel spreader plates under them with some support provided by what looks like a wooden knee glassed into the hull - not a very clever design - the lower arm of the knee has pulled the hull in slightly too. Anyway I plan to have the deck cut out and the whole arrangement strengthened and re glassed back. The starboard side is fine.

 

[Concerto]

What sort of surveyor would say " it's benn ok for 33 years so should be ok for another"?

When the truth is, it's been ok for 33 years but it's now failing adn should be properly investigated and repaired before it fail completely.

The surveyor is a very well known and trusted surveyor who has also been president of the surveyors association in the UK. I have known him for 30+ years and respect his detailed knowledge of yacht construction and encycolpaedic knowledge of known fault areas on a huge number of production yachts. He even asked the previous owner about it, and he said the same comment came up when he had the boat surveyed on his purchase 16 years earlier (I have a copy of that survey). I still see the previous owner regularly as we are both members of the same club and he is very impressed with the renovations I have already made and still plan to do. My experience of boats is vast, including building some similar sized boats from plans, so I am very familiar with many major structural issues relating to keels, masts and rudders.

The orginal design was at fault, not shoddy construction. The cost of making the deck perfectly flat is far greater than just a bit of epoxy and would involve removing the mast plus some major new stainless steel manufacturing and shortening the substantial s/s tie bar. All of which are within my skills and that of an engineering shop. The amount of lift is less than 5mm and has not affected the structural integrity of the boat. A bodger could quite easily have just filled the top of the deck to hide the problem and repainted the deck.

Why fix something that is not broke and just settled to a new position? Ultimately it is my decision to follow professional advice and leave alone.

 

[ronassis]

Hi guys thanks for all the help. I will be down at boat tomorrow and hope to take off inner sub deck lining and get the yard surveyor to come and look. I think Plevier and jonjon are correct though and I may not be able to see anything. Hard to accept that the mast is secured just by u bolts through the deck but I haven't heard any scare stories re dismasting on SO32 s. Hope things can be sorted without too much financial pain. May also try and access jeanneau tech help.

 

[30boat]

The surveyor is a very well known and trusted surveyor who has also been president of the surveyors association in the UK. I have known him for 30+ years and respect his detailed knowledge of yacht construction and encycolpaedic knowledge of known fault areas on a huge number of production yachts. He even asked the previous owner about it, and he said the same comment came up when he had the boat surveyed on his purchase 16 years earlier (I have a copy of that survey). I still see the previous owner regularly as we are both members of the same club and he is very impressed with the renovations I have already made and still plan to do. My experience of boats is vast, including building some similar sized boats from plans, so I am very familiar with many major structural issues relating to keels, masts and rudders.

The orginal design was at fault, not shoddy construction. The cost of making the deck perfectly flat is far greater than just a bit of epoxy and would involve removing the mast plus some major new stainless steel manufacturing and shortening the substantial s/s tie bar. All of which are within my skills and that of an engineering shop. The amount of lift is less than 5mm and has not affected the structural integrity of the boat. A bodger could quite easily have just filled the top of the deck to hide the problem and repainted the deck.

Why fix something that is not broke and just settled to a new position? Ultimately it is my decision to follow professional advice and leave alone.

I find this interesting because I own the First Fulmar built.There was a very small deformation on deck when I first got the boat.When I replaced the mast I unbolted the chainplates and found no misalignment or even that the tie bars were too long.I put everything back with new bolts and don't predict any problems in that area.

 

[Concerto]

I find this interesting because I own the First Fulmar built.There was a very small deformation on deck when I first got the boat.When I replaced the mast I unbolted the chainplates and found no misalignment or even that the tie bars were too long.I put everything back with new bolts and don't predict any problems in that area.

That is interesting to hear and confirms exactly what the surveyor had said.

In the past I heard that hull No.1 was in Holland and very well looked after. When did you purchase your Fulmar and when did it arrive in Portugal?

 

[vyv_cox]

The lower shroud chainplates on Sadler 34s are right-angled and a little on the thin side. After a few years with shrouds at the correct tightness the plates bend and the deck is pushed upwards a little. Mike Lucas sell heavier gauge ones that solve the problem.

 

[30boat]

That is interesting to hear and confirms exactly what the surveyor had said.

In the past I heard that hull No.1 was in Holland and very well looked after. When did you purchase your Fulmar and when did it arrive in Portugal?

She was owned by a Belgian who arrived in the Algarve around 1998.I bought her in 2001 when I spotted her in Culatra with a for sale sign.By then she was a bit run down with all the cabin lining drooping and a few other things.She's in great shape now although I'll have to do her bottom one of these years.

 

[Spyro]

I noticed a slight bulge in the deck of my Jeanneau Attalia All this talk of tie bars and other fixing was obviousy thought not to be required by Jeanneau. There is a large elbow or knee section holding the hull to the deck but the actual chain plate is held only with a u bolt and a rather small stainless plate. I replaced the plate with a larger one. That was 5 years ago. the bulge hasn't got any worse and I'm happy with it.

 

[30boat]

I noticed a slight bulge in the deck of my Jeanneau Attalia All this talk of tie bars and other fixing was obviousy thought not to be required by Jeanneau. There is a large elbow or knee section holding the hull to the deck but the actual chain plate is held only with a u bolt and a rather small stainless plate. I replaced the plate with a larger one. That was 5 years ago. the bulge hasn't got any worse and I'm happy with it.

All the Jeannaux of the time had that arrangement and there were no failiures so don't worry.

 

[Lakesailor]

I think Davidpbo had a similar problem which he repaired. I think it became a bit of a marathon job. Difficult access etc.

 

[ronassis]

Hi again...................went down to my jeanneau 32, took off lining under the sidedeck and was pleased to see that the whole assembly under the deck was clearly visible and easily accessible with no cutting away required. The arrangement is indeed 2 hefty u bolts through the deck and then through a substantial steel plate. Instead of plywood there is a thick backing/bonding material. No water anywhere just nice dry fibreglass !!
Anyway I asked the riggers who said the rig had not moved and then got the yard shipwright boss/surveyor to look. He confirmed the riggers advice looked top and bottom and concluded that the whole arrangement had'not moved since the day the boat was launched'. He based this on the appearance of the underdeck fixtures and gave the thick bonding pad[ he gave it a name I cannot remember] and plate the thumbs up. He further suggested that the few small cracks and slight hump was probably caused by the inside nuts having been tightened a little too much in construction and had after launch and in 10 years use squeezed the small area between and around the ubolts. So in his opinion it was perfectly strong and ok. I may file out and fill the few small cracks.
S0 feeling relieved and glad that it is easily accessible to keep an eye on it. CARRY ON SAILING.

 

[oldsaltoz]

Great news, do the 'U' bolts have the reinforced plate between the entry points on deck? they help to reduce the squeezing effect.

Good luck and fair winds.

 

[Plevier]

Hi again...................went down to my jeanneau 32, took off lining under the sidedeck and was pleased to see that the whole assembly under the deck was clearly visible and easily accessible with no cutting away required. The arrangement is indeed 2 hefty u bolts through the deck and then through a substantial steel plate. Instead of plywood there is a thick backing/bonding material. No water anywhere just nice dry fibreglass !!
Anyway I asked the riggers who said the rig had not moved and then got the yard shipwright boss/surveyor to look. He confirmed the riggers advice looked top and bottom and concluded that the whole arrangement had'not moved since the day the boat was launched'. He based this on the appearance of the underdeck fixtures and gave the thick bonding pad[ he gave it a name I cannot remember] and plate the thumbs up. He further suggested that the few small cracks and slight hump was probably caused by the inside nuts having been tightened a little too much in construction and had after launch and in 10 years use squeezed the small area between and around the ubolts. So in his opinion it was perfectly strong and ok. I may file out and fill the few small cracks.
S0 feeling relieved and glad that it is easily accessible to keep an eye on it. CARRY ON SAILING.

Good, I'm glad the doom mongers not familiar with the design have been foiled!
I'm a bit puzzled by one thing. You said there was a hump; how could this be caused by the U bolts being overtightened in assembly? That would give you a dip in the deck surely?
I didn't see any hump or dip or gel coat cracks on my SO32.
One thing to be aware of, it is not overall the stiffest of hulls. Following the procedures in the Selden book and using a Loos gauge, I ended up with the rigging at just about the maximum permissible tension but in brisk upwind sailing the leeward side would still go slack.
Do you know the owners forum, http://www.jeanneau-owners.com/ , lots of info on their including some interesting SO32 mods such as mainsheet traveller, adjustable backstay etc.
Nice cruising boat. Have fun.