keel J92s technical question

[jens bastian]

Hi all,

i need to make some repairs on the keel of my J92s build in France 2006. Therefor i am looking for technical drawings or photos of the construction and setup of the composite of the keel. Especially the section where the keel is glued and bolted to he hull and sump. Does anybody have an idea where to get this from ? I already wrote an email to Jeurope and Jboats but it seems that they are too busy to answer...  If i dont get any i have to open up the whole upper section of the keel, what i badly try to avoid.

Thanks in advance and regards

Jens

[Dick Heijdra]

Hello Jens,

You better phone J Europe and try to get them involved. After you have established contact you can send pix and so on. But get them committed first. I am still waiting for an answer on a question concerning my rudder...

Dick Heijdra

----

Pronk.

Heemraadssingel 170

3021 DL Rotterdam

+31 (0)10 76 70 120

di...@pronkstudio.nl

www.pronkstudio.nl

[Brian]

Jens,
I have uploaded a "typical keel boat detail" in the file folder which
I received from
Alan Johnstone back in August when I had a keel question. After doing
the repair, I found out the sketch is not as detailed as I would have
liked. I will place a picture of my keel and my original problem in
the file folder as well. Below is my question to J-boats and the
response.


Brian,

There is only one joint between the lead casting and the molded keel
sump. I assume you mean to say the surveyor made note of two cracks
on
the side of the keel?

When the keel is attached at the factory, the area between the keel
and
the molded keel sump is covered with an epoxy paste mixture, the hull
is
then set into place on top of the supported keel, then aligned and
braced. Once the epoxy paste cures, the keel bolts are then torqued
to
their final settings and the keel joint is then covered with a
fiberglass tape approximately 6" wide. This is a non structural
finishing detail between the keel casting and the molded keel sump
joint. It is conceivable that a horizontal crack may appear at the
edges
of the tape (top and bottom), and this may or may not indicate a
problem. Assuming there is no delamination of the tape itself then
the
repair that you suggest below sounds reasonable. If there is
delamination of the tape, then further investigation is should be
carried out.

In any case, it is prudent to have the bolts inspected and re-torqued
as
necessary and for the surveyor to have inspected the general
structural
integrity of the keel sump, keel floors, etc.. to be sure there are
no
signs of any cracking in any critical areas of the keel floors or the
tabbing that attaches these floors to the keel sump or hull. The J/92
molded keel sump extends approx. 11" below the hull at the trailing
edge. The attached sketch will give you a visual idea of how the
joint
is constructed.

I am also attaching the best practices article regarding keel
inspection
that we recently published after learning of keel failures of two
J/80s. This should help you take a conservative approach to the keel
inspection process and give you more confidence in the integrity of
the
boat.

Best Regards,

Alan Johnstone
J/Boats, Inc.



I have just purchased a 1993 J-92. The boat was surveyed and the
surveyor made a note about two keel joints. The surveying made no
mention of concern. I didn't think much about it until reading some
issues about keel failures. Reading the specs it the joint was
epoxied, bolted and fiberglassed so I suppose it is possible two
joints could appear. I am hoping I did not just buy something I will
need to do a lot of work. The plan was to grind the joint down, fill
with epoxy and paint unless I should be concerend about a keel
failure, which then may require dropping the keel and rejoining. My
question is: at what distance is the joint from the bottom of the
boat? Is two joints possible or is a failure already occuring. I have
pictures available if it would help. Thanks, Brian Kerr

[Jens Bastian]

Hi Brian,

i just checked the pic. I had a grounding and due to that accident the
folowing crack appeared. It seems that on your pic you have the same
crack visible. Does it look similar ?

[Dick Heijdra]

Hi Jens,

I had a similar crack at the same place. I did not ground but experienced extremely heavy seas with waves of about 3metres high in 34 knots of wind which hammered the hull and keel and shook the boat. I sought advice at J Europe, J-UK, J-Holland and an independent surveyor as I was very worried by the sight of this crack. All answers comforted me. I was not to worry and was advised to check the torque of the keel bolts and to repair the crack with filler, sand everything smooth afterwards and apply antifouling. Hope this takes your worries away!

Mit freundlichen Grüßen,

[Dick Heijdra]

Hi Jens,

This is what I experienced:

[Dick Heijdra]

Jens,

The answer I got from Paul Heys, J-UK:

Hi Dick, what you are seeing is a delamination of the fairing bandage that covers the joint between the keel and hull.

 

This is not structural.

 

The solution is to grind away the loose material, dry and clean the surfaces then relamainate and re fair

 

Best regards

 

Paul Heys

 

 

 

Key Yachting Ltd

1 Mariners House

High Street

Hamble

Southampton

SO31 4JF

 

Tel: +44-(0)23 8045 5669

Fax: +44-(0)23 8045 5770

Mob: +44-(0)7802 264141

 

www.keyyachting.com

[Jens Bastian]

wow, looks even worse.

Am 03.11.2009 um 17:41 schrieb Dick Heijdra:

Hi Jens,

This is what I experienced:

<Unknown-1.jpeg>

[Jens Bastian]

perfect ! Helps to get relaxed. I am worry about the antifouling whats missing at the hull/keel connection as well.

[Jens Bastian]

Hi Dick,

do you mean the horizontal crack ca. 40 cm below the hull/keel connection ? And what the hell are you doing in these hurricane conditions ? Sounds interesting. A good friend of mine just finnished the minitransat placed 22nd with his pogo 6.5. Straight from France to Brazil. 50% ugly weather and believe it or not: no cracks...

Best regards

Jens

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[Dick Heijdra]

She'll be out of the water end of november, I'm curious of what I will see after a busy season... Let you know. She sails fantastic though, on both tacks. So I'm not expecting any horrors!

[Jens Bastian]

Well, lets hope the best. Same was with me. She was faster than ever with new sails from ukhalsey. After i adjusted the mastfall to almost nothing i was able to point higher and get very close to the datas from polardiag.

[Dick Heijdra]

that's correct, about 40cm's below the hull. I wasn't seeking those conditions, the met-office just happened to get it all wrong predicted!

[Jens Bastian]

same here all year around. using the most sophisticated computers they were all wrong this season. whenever i decided to stay in the harbour the weather wasnt bad. and when i decided to go and sail i generally get wet.

thanks a lot for your support, when i am in Holland next time lets have a beer together !

[Dick Heijdra]

Allways wellcome Jens!

[jwhj92s]

Hello guys.

I own hull #30, a J92S, from 2006, built by JEurope. We pulled her
out of the water yesterday for a routine bottom job and I discovered a
crack in the exact same place on my keel. There was no grounding and
no pounding in 35kt winds. How did your repairs go? From your posts,
the crack is not structural, just a cracking of the fairing compound
between the joint of the hull and the keel. I think I will check my
keel bolts, fair the crack away and check again in 1 year. Is there
anything else I should know???

John H
Pier Pressure

On Nov 3, 11:12 am, Dick Heijdra <d...@pronkstudio.nl> wrote:
> Allways wellcome Jens!
>
> Dick Heijdra
>
> ----
>
> Pronk.
>
> Heemraadssingel 170
> 3021 DL Rotterdam
> +31 (0)10 76 70 120

> d...@pronkstudio.nl
>
> www.pronkstudio.nl

[Jens Bastian]

[Chris Farrell]

What torque settings did you use?

I have just bought a 1995 j92 that has a crack in the fin where the fibreglass/keel join.

I put the boat in a cradle and now want to re torque the nuts.

My plan is to::

New spacer washers to move the bite point up the already stressed thread.

New 316 nuts
as an engineer,I recommend that owners do not kubricate the threads,
I do recommend that the spacer is lubricated so as to reduce friction onnut face and increase friction on thread, the bit that does the work of holding the keel to the hull.