dropping a centerboard

[Justin_NSA]

BWY has one set aside for me. Gail and I were talking about whether or not the cable, washers, nuts etc need to be replaced also so I said I would inspect it this weekend before I place an order.
I really like the design of IdaSailor's solid board but I can't justify the additional cost. If anything, I hope this thread brought out some thoughts; 1) Inspect your centerboard occasionally for damage 2) you have at least a couple options if you need a replacement board

 

[walt]

Doug, do you rememeber what the trailing edge of the Idasailor centerboard looks like?

This is from memory but the stock 26S centerboard has about a 1/2 or 3/4 inch flat on the trailing edge (rather than a smooth transition to a sharp trailing edge). The foil shape on my centeboard was not bad but did have a few flat spots which would have deviated from a Naca shape.

I think the main benifit of the flat on the trailing edge is structural and easier to manufacture. I did a quick search and it looks like it has somewhat worse L/D but maybe the flat has some positive influence on how the foil stalls?

I believe the Idasailor parts are all CNC milled so they should have about perfect surface shape.

 

[Doug J]

Trailing edge

Walt, I really don't remember what the trailing edge of the CB looks like, can't see it anymore since it's up inside the cavity, I don't think I can even get my hand in there, but maybe I'll check it out tonight and let you know.

My guess is that it is tapered to a narrow edge. I think it has to be. If you look at the cavity it has to go into it tappers to a narrow edge.

Here's a few pic's, hard to tell from looking at them though, accept you can see the shape of the cavity.

 

[walt]

I dont have a good shot of the blunt trailing edge of the stock centerboard but you can sort of see it in the attached picture. The blunt edge is a little more pronounced at the top but its carried over the total lenght.

 

[Sumner]

When I bought my CB in 05', of course Idasailor did have something to say about the added advantage over the OEM CB, foil shape etc. I liked the idea of it not being hollow, thinking I would never have the interior rot issue to worry about again. If I recall, I paid around $450 for it.

We have one also, it came with the boat and we felt it and the Ida rudder were worth spending a little more on the boat when we bought it. I'm still glad that I have it, but I was just passing on what the Ida technician told me on the phone. I'll bet it does have some advantage over the stock one, but according to them now they don't feel it is enough to entice people to spend the extra. Of course we might never know the whole story or that could be it.

c ya,

Sum

 

[Bob 04 H260]

trailing edge

The trailing edge on the stock Mac rudder and center board both have a narrow flat surface. I looked at it the first time and thought it was just manufactured that way. In reading one of the sail trimming books I have I discovered that this flat area is intentional and results in less drag. Intuitively I would expect the sharp trailing edge to perform better but apparently not.
Bob

 

[Justin_NSA]

Need your comments

I received my new keel from BWY and I opened the crate today. I see numerous holes drilled into this thing and I'm thinking this can't be right. I tried to call BWY but they were closed already. So before I try again tomorrow I'd like some comments on this:

The pivot end of the keel looks like it has a hole for the rod and one for the cable. I don't know what the 2 smaller holes are for. Now check out the other end in the second pic

What are all of these holes doing on the opposite end?! Between the red markings they left and all of the holes, it looks like they started to drill the wrong end. These holes are exposing the hollow core and spline. That's exactly why I ordered a new keel as seen in my earlier post. I suppose I could fill these but why should I repair a new keel? Anyway, I'll find out what BWY has to say tomorrow. Comments are encouraged here!

 

[Paul Brinkley]

Re: Need your comments

Justin- your centerboard is hollow. If you seal all of the holes so water can't fill it, it will float (won't drop down). You must have holes to let water in and out. -Paul

 

[Justin_NSA]

Paul,
My old keel doesn't have those holes. And what about that red "V" mark on the wrong end? None of the other centerboard pics in this thread have so many holes.
Wouldn't letting water inside cause the wooden spline to rot like in my earlier post? The holes for the pivot and cable are in solid 'glass.

 

[walt]

That is about how many holes my CB has. I havent taken the CB apart but Im pretty sure there is a single stringer running top to bottom (ie, the stringer is about 6 foot long). The stringer forms two air pockets in the CB. One is toward the leading edge and the other at the trailing edge - since the stringer runs about in the middle.

Since two air pockets, there are two sets of holes on both the leading and trailing edge. I got rid of about 1/2 those holes but it was painful getting there - not sure it was worth it.

Paul is correct, if you just plug the holes, the CB floats and will not drop..

 

[Paul Brinkley]

Justin, I had to do some work on my CB right after I got my boat (replace broken bolt, new cable, install bushing in pivot hole, et.). IIRC, I had some extra holes in my board, too. In the course of my repairs, I started sealing those holes. Fortunately, I read about the need for the holes (either on this site or another one) before I finished and reinstalled the board. I left 2 holes at each end, and the board works fine. Yes, allowing water in there probably does cause the stringer to rot. If it worries you, try some of the things other posters have done to preserve the stringer. Not sure about the red markings, except that the V does look like someone was going to put the cable on that end. -Paul

 

[Justin_NSA]

BWY responded and affirmed as you all have that the holes should be there so the centerboard will sink. They are also suspicious that someone may have tried to drill the wrong end first as evidenced by the red markings.

Based on the core damage to my CB, I presented some thoughts I had on the design. BWY hasn't responded yet. Is it possible that MacGregor designed this system for a trailorsailer that is hauled out after every use and not left in water for a whole season? Did they expect that there would be times between use where the CB could dry out on the trailer? Lastly, if that were the case, would I be better off filling the voids with sand or something and plugging the holes? The holes for the pivot rod and cable are in solid 'glas

 

[Jansen]

Mine is a 92 26s and it has the exterior bolts, they must have changed mid year. I need to repair mine also. Is there any metal in the centerboard?

 

[Justin_NSA]

The response from BWY is that the CB core is a mixture of resin and shredded fiberglass, so it shouldn't harm it to be continuously submerged.
I think I now have a spare rudder and CB once I patch the damage.