Core Sound 17 centerboard play and and maintenance

[Mark Hensley]

Hi All,

 

I'm new to this forum and the excited new 3rd owner of a Core Sound 17 Mk 1 that I believe was built circa 2015 (not sure hull # or where to find it).  I'm a lifelong dinghy sailor but am new to the cat ketch rig and to the this design in particular.  After buying the boat in Lake Placid a couple weekends ago, I took it for a first sail on Lake Champlain and really enjoyed it.  Having never rigged a cat ketch before it took me a few hours to figure out how to rig it and while I'm sure I didn't have everything quite right, it was right enough to have a good sail.

 

I do have two questions though related to the center board (apologies if there is a thread on these already and please feel free to point me to those).

 

1.  The center board has two lines - an uphaul and a downhaul each with cleats.  My boat appeared to be missing either a line or maybe what I'm surmising should be a bungee on the downhaul so that the board can kick up if you hit bottom.  Is that correct and if so, would anyone have any details on the bungee length, set up they could share?

 

2.  At one point in my sail, the wind died and we were getting rocked about in some waves.  The centerboard was slapping/slamming back and forth in the trunk.  Seemed to be about 3/8" - 1/2" of play between the board and the top of the trunk.  It seemed like too much play to me and the slamming severe enough that in bigger chop it might stress the board pivot/trunk.  Any advice on how to minimize that slamming and what if any maintenance/check up I should do on the centerboard pivot?

 

Thanks in advance for any advice.

 

Mark

 

 

[Hirilonde]

Pictures please.

[Alan Stewart]

Hey Mark, 

Welcome to the forum! Here is the centerboard rigging detail from the plans. There is indeed a bungee for the downhaul but we've also rigged them with breakaway cleats. Usually i pull the board own by grabbing both lines just behind the horn and then once its down i take up the downhaul slack. 

 

By design the king posts are 1 5/16" thick and the board is 1 1/8" leaving 3/16" gap total which is partially used up by a layer of fiberglass on either side of the centerboard itself and glass on the inside of the trunk sides. a 1/8" total gap 1/16" per side we consider "perfect" to avoid too much rattle but also the very hard to correct "board too thick" problem. It sounds like you've got too much play. The only real way to fix that is to make the board thicker (just the top part) which isn't exactly "easy" but definitely doable with just layers of fiberglass added to either side. There should be enough play in the hole for the pivot bolt that i wouldn't worry too much about stressing the pin or bolt it sees far more stress running aground, bouncing on the trailer etc. 

-Alan

 

[Mark Hensley]

@Alan Stewart - thank you so much for the prompt and informative reply!  Super helpful and exactly what I needed!  I'll measure that gap now and add a some fiberglass if needed to tighten it up a bit.

 

@Hirilonde - thanks for the reply as well.  A couple of pictures  attached from my sail.  The red parachute chord on the port side of the centerboard trunk was my game day hack for not having a bungee chord.  I was a bit nervous I would hit something so was conservative when approaching shallows. 

 

 

[Andy B]

Your "game day hack" is not bad.  My centerboard has the opposite problem, it's too tight.  That makes it a bear to pull down.  I took out the bungee arrangement because it just made it harder.  I sail mostly over sandy bottoms, so it's not a huge concern.  I have a break away cleat for my moments of stupidity forgetfulness.

 

I've thought about tying a stout bungee cord to the centerboard.  It would not be used to lower the board, but just used when I think needed.  I'd just leave the normal downhaul loose and put the bungee through the cleat.

[Reacher]

Mr Hensley,

I use a breakaway cleat for the centerboard downhaul. The only time it popped was from coming in too far at the boat launch and the board hit the ramp. The board floated up, but it does require resetting the downhaul to put it down again. If you sail in shallow water you might prefer a bungee for its self reset.

 

A suggestion is to not rely solely on the uphaul cleat when trailering unless  you have a block or bunk that would prevent the board from hitting the ground. I tie a short line between the horn and the uphaul padeye.

 

it looks like your sail number is 355. That’s a clue as to when the plans were sold.

[Andy B]

@Mark Hensley, I think this is your boat based on where you bought it and the color scheme.  Hopefully I'm not a creeper, I just remember it because I was looking at the time and it was great deal (to the guy you bought it from):

 

 

[Reacher]

More free advice, it might be worth the price…

 

Your line setup looks pretty clean. One thing I noticed is that the port side of the main sheet is all the way out to the stop knot on the end of the line. It should be balanced so you can let the sail out from either side.

 

One time after making some random jibes and circles I tacked and found I had almost no line left on the high side to ease the sail. No harm that time but I took note.

[Don Silsbe]

A quick and dirty solution to your c/b play issue might be to add one or two thin strips of wood along the top of the inside surfaces of your c/b slot.  That would prevent the “horn” part of the c/b from wobbling.  You could tape them in place for a trial run.  They need to be long enough to touch the horn in its full range of travel.

[Mark Hensley]

Hi Everyone that replied to my original post.  Thank you for the replies and suggestions - what a great community of supporters!  I wanted to apologize for not replying to you all at the time - life overtook for me for a variety of reasons this last six months and I just never got back to this forum.  I am gearing up for a Lake Champlain multi-day trip in June so now am back at it.

 

@Andy B - that is definitely my boat for which you found the 2022 ad.  It really is nicely built and I'm glad to have it.
 

@Reacher - thanks for the advice on centering the sheets.  I found out the hard way about the problem you described and as this is the first boat I have had with this sheet setup it is not something I am used to doing.  I am going to replace the sheets as they are a bit too short and I'm planning to add some sort of marker in the middle of the sheet as a reference for keeping it centered.

 

@Don Silsbe - I like your suggestion for taping wood in the centerboard trunk - unfortunately - I did not see your suggestion until I had already fattened up the board with a few layers of fiberglass.

 

Thanks all.

[Don Silsbe]

Adding ‘glass to the board is the way to go.  Taping wood strips was a temporary fix.

 

When my sheets get out of kilter, I simply grasp both ends, uncleat them both, and haul them in.  No need for precision here.

[PadrePoint]

I put a red mark with a Magic Marker at the mid point of my sheets, giving me a visual indicator of where the sheets are, sometimes adjusting the two ends to closer to middle. 
Yes, it’s quite a surprise when loosening a sheet in a gust and having the stopper knot appear in my hand.