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Keel Bolts and General Topics on Keel - Keel infiltration
21 December 2020 - 16:40
#1
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SERGE
Join Date: 22 November 2015
Posts: 13

Keel infiltration

Dear Swan Lovers

 

My swan 38 is now on dry dock for winter.

Some water is getting out from the keel (small drops).

There is no visible cracks between keel and hull.

Wherebdoes the infiltration come from ?

How to proceed to eleminate this ?

Many thanks in advance for your help.
13 January 2021 - 15:49
#2
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Kairos
Join Date: 20 July 2017
Posts: 119

Hi Serge,

I am by no means an expert (luckily) and others might be better placed to answer but this looks a bit like (the early signs of) osmosis to me ...?

Cheers

Stefan

Kairos - 57/043

 

 
13 January 2021 - 20:50
#3
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matteosalamon
Join Date: 29 January 2007
Posts: 1049

Dear Serge,

the keel is lead, and it's likely there is a filler on top of the lead and under the primer/antifouling. Could it be some water infiltrated  underneath the filler?

Please keep us posted on this!

Fair winds!

matteo (47/069 Vanessa)
16 January 2021 - 09:09
#4
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Algol
Join Date: 17 July 2020
Posts: 104

Hi,

is there not, as in others like 57, some places in the keel to add ballast in front or rear of the keel to adjust the boat balance ?

it looks like the front one...

Professor Lars can tell for sure if it is...

Algol (57 #007)
16 January 2021 - 09:22
#5
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matteosalamon
Join Date: 29 January 2007
Posts: 1049

Dear Algol,

Serge's boat is a38, and there are no pockets in this model. Hope to see more and detailed images from Serge.

Fair winds!

matteo (47/069 Vanessa)
16 January 2021 - 12:52
#6
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the professor
Join Date: 02 January 2008
Posts: 1547

Dear all

Also the 38 has keel pockets, a round one forward, and an oval one aft, visible on SERGE's photo.
According to the records both pockets are filled from 022 onwards, and it needs to be checked if the pockets are filled, but the contours visible.
Kind regards
Lars
16 January 2021 - 12:59
#7
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matteosalamon
Join Date: 29 January 2007
Posts: 1049

Dear Lars,

thank you! I couldn't find pockets on my old 38/067 Only You (and I now understand why, they have been filled since delivering) and thought all the 38's did not have pockets !

A new portion of knowledge on my small knowledge on S&S Swan!

Fair winds!

matteo (48/069 Vanessa)
24 January 2021 - 10:45
#8
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SERGE
Join Date: 22 November 2015
Posts: 13

Thanks a lot for your comments.

We scraped and cleaned around the forward keel pocket from which a few drops of water came.

The filler was soft and wet.

Once remove we can see that the outline of the keel pocket is not rectilinean : it present small asperities : taces of corrosion or electrolysis ????

This place being now dry we plan to fill it with an epoxy filler.

some questions:

How are these keel pockets fixed ?

What is the weight of each keel pocket ?

What is the use ?? !!!

Thank you in advance for your kindly answers.
24 January 2021 - 18:30
#9
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the professor
Join Date: 02 January 2008
Posts: 1547

Dear Serge

Pls note that the Swan 38 was a hot racing yacht when new, and therefore two empty keel pockets (holes through the keel) taking about 200 kg of lead each were incorporated into the lead keel casting. By filling the pockets to various degrees the weight and longitudinal trim of the boat could be adjusted to some extent in order to optimize the rating.
 
As said earlier in this thread both pockets were filled from hull 022 (the 38 was designed to rate as a one tonner with the short rig, but the owners wanted the tall rig and the one ton version was not in demand).
 
It should be checked on your keel if the area within the pocket circumference is completely filled with lead through the full thickness of the pocket. This can be done for example by tapping with a hammer. There is likely to be a seam visible in the lead around the pocket circumference, this suggests that the yard had already cast many keels with empty pockets (S38 was series produced) and filled them afterwards when the instruction from S&S came.
 
All filler containing moisture should be removed, it should be checked that the lead in the pockets is securely fixed in position, and the seam sealed watertight with epoxy.
Kind regards
Lars
25 January 2021 - 20:08
#10
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robmably
Join Date: 01 March 2007
Posts: 147

Serge,

I do not how similar the keel pockets in the 38 are to the 47, but here are some pictures which may be helpful? On my 47 ( 1977), each pocket has a grp plate which was screwed into the lead to hold the foam inside the void. Ours was saturated, so we removed it all and replaced. We also added some lead, which due the internal shape, tied itself firmly inplace. We made up new grp covers and faired it in with bog before the standard epoxy layer treatment, making sure we used the correct primers etc.

Hope this helps.

Rob

Sarabande 47/029
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