Keel Modifications SO 37.1

[pelyachting]

I have been trying now for the past few years to improve my upwind
> stability with this SO37.1.
> First I put in a postive roach fully batten main instead of the furling ,
> in conjunction with a flat 110% genoa.I stripped her weight down and stow my
> anchor and chain over the keel in the saloon stool seat.
>
> Despite this, over 14knots and she's getting bowled over. I want to
> increase the draft of my keel but I worry about the fact the shallow already
> displaces around 100kg more than the long fin keel.Can I add to my keel
> without over stressing the rig/ If so how much length and weight can I add?
> Also do I need to compensate my rudder length also?
>
> Some people suggest a lightweight foam enclosed in epoxy to achieve keel
> length without weight. I prefer bolting a 150kg torpedo style bulb down
> below.
>
> Please any suggestions or past experiments would be appreciated.
>
> Thank you
> Wonky Upwind

[MartyB]

If it is a keel issue, I would consult the designer if possible. OR, talk to mars Keel on the east coast of the US. They can make a whole new keel, either them design, or they can make an equal to a deeper draft of your boat. That to me would be a bit safer money expense than just adding, then realizing it does not work etc. taking the whole thing off, then putting a new keel on later. Or worst yet, making the issue you have worst yet.

And yes you would want to deepen the rudder too. This will help in keeping the rudder in control too.

This also seems to be an issue with shoal draft boats from Jeanneau to a degree. even some of the deeper draft boats at 15 knots are having to reef to make the balance better.

marty

[MalcolmP]

The reduced rudder area may be the main problem, but if it is extended beyond the keel depth obviously becomes very vulnerable. As you have had the problem for several years I presume you have fully experimented with sail trim, in particular dumping the mainsheet track in gusts.

Worth contacting the designers at Groupe Fauroux as well

www.fauroux.com

[offshore]

Hi

We have a friend with a 39i with shoal draft keel. Compared to our 36i with a standard keel he drifts more to leeward and has to reef earlier. That being said, compared to all of the true racing boats old and new in our fleet, we are also one of the earliest to reef. In gusts his boat is much more likely to round up than us as his rudder is about a foot shorter .

Many years ago I sailed on an IOR boat where the owner cut a big hole out of the centre of the keel and added the weight to the bottom. That was lead, and it was easy to cut. I guess they checked where the keel bolts were before they started.

Barry

[davideso37]

Wonky upwind,

I know this thread is probably dead cold but in case you are still researching the topic I will add my thoughts. As regards the rig the US Spars web site shows that it is a Z601 section. US Spars is the Z Spars company in the USA so here is another resource for Jeanneau owners to use. Now the Z601 is the same section as on the SO40 so my guess is that the mast is OK but you would want to check the rigging. Rig stresses are often based on the load in the rig at 30 degrees heel. If you increase the weight or the length of the keeo the stresses on the rig will increase. You may need to change the shrouds from 1X19 to Dyform or go up a mm in the spec but there are enough Jeanneau owner manuals on the manufactures web site to download and see all the rigging sizes for yachts with similar ballast and keel depth. Also a good rigger should be able to confirms the safety factor in the current rig. Regarding the round up all yacht round up if the centre of effort is too far behind the centre of lateral resistance. So you need to dump the main before the yacht starts to round up. Dumping the main moves the centre of effort forward and will keep the yacht tracking hard and fast. In heavy airs we give a wide berth to yachts on the same tack and presume that at some stage they will round up so I think that more ballast or a longer keel will not help the rounding up problem. It may help the leeward drift and let you carry the full rig longer.
Regards
David

[rene]

Hi,

MY advice would be: trade your shaol keel version in for a deep keel version. Just a thought.

Rene