Keel Vibration - Advice?

[northcave]

I have recently bought a swing keel Beneteau 26 from 1986. On our first passage from Salcombe to Dartmouth yesterday there would be shudder / vibration from the keel as we went over 6.5 - 7 Kts. It is a fairly disconcerting and it makes the whole hull vibrate.

Does anyone have any experience with this and or any recommendations?

 

[Jackdaw]

Tim,

My First 260 is newer but has the same basic keel. It is a well regarded system, Finot, Beneteau, and Pogo have been using them for years in many boats.

There is several places to look, and none of it sadly is easy to do. Better while pulled. First is the swing bearing, shown in the drawing as parts 7-11. If the bolts (up from the bottom into part 11) are loose, or the bearing (9) is worn, the keel with vibrate. Next is the sliding 'pucks' than keep the keel tight in the box. If they are worn there will be play. All of these parts are available from Beneteau.

Last is the keel being WAY off of fair. It is made of cast iron and in salt can rust badly if not looked after.

Hope some of this helps and you are sorted out soon.

 

[northcave]

Thanks. Out of interest how does ones go about having it faired in? I mean there must be some sort of measuring device and it doesn't sound like something you can do in the yard yourself.

 

[Jackdaw]

Thanks. Out of interest how does ones go about having it faired in? I mean there must be some sort of measuring device and it doesn't sound like something you can do in the yard yourself.

For it to be bad enough to add a flutter under sail you'd be able to see it. It would be eaten away in places that really added asymmetry to the shape. The keel shape is a standard NACA 6 series foil.

Sadly my guess would be on the bearings.