waardij
2015-05-23T09:23:21Z
Hi,

I am new here. Bought a SS26 last winter and am very pleased with it, excellent sailor. Fast and at the same time very manageable. The only 'problem' I have is keel resonance. Especially when sailing closed to the wind, above say 5.3kn, there is a low sound coming from the keel. When I raise the keel a bit, this helps, but at a higher speeds it still occurs.
Is this normal? And when not normal, is there something I can do about it? Thanks for any help/suggestions.

Hans
PeterL
2015-05-26T09:39:22Z
Hello Hans,
There is a detailed article in the Super Seal Manual ( see the main menu / about the PSSA/regalia and manuals ) by Dick Landon ref 91/4 where he investigates resonance on a Parker 27.On his boat it occurred particularly at 5.25 kts.Briefly,he finds that using rubber spacers on the keel guides instead of steel washers was partially effective as was improving the leading edge and the trailing edge of the keel.He also considered that stiffening the box would further help but did not pursue that.
I suggest that you should read the full article which is complex.The manual costs £10 to members.It is worth checking that this particular article is still bound within the current manual version,which has lots of useful information.
Peter

PS We do not have this issue on our Seal 27 #131 but do have a substantial full height hardwood strip roughly midway on each outer face of the box with no other obvious purpose (of course they are twin compression posts)so perhaps this was a works modification by John Baker or Bill Parker that was applied to later boats ? It would be fairly easy to add such strips ( if the decor allows) using Sikaflex 292 to bond the strips - if they are not already on your boat.
waardij
2015-05-26T10:57:34Z
Thank you very much for the reply! I have the manual, and will check (it is on board at the moment), but do not remember seeing such article. Apart from the article, I will check whether the keel is resonating within the box, or the box is taking part in the resonance. depending on this I could indeed improve the fit of the keel (in a way that dampens as well as improve the fit) or stiffen the box. I would expect that it can resonate a long time before anything really goes wrong, it is just a bit uncanny, when you hear (and feel) such noise.

Hans