138 Pound Centerboard

[Erik Hardtle]

Looking for more stability and possibly less heeling I added 138 LBS of lead to the hollow centerboard. This is a major modification. I used my experience of a weighted centerboard from my O'Day 19 to design the changes.





I tested it on a lift... sea trials soon.....

Click on the WWW button below to go to my website and check out more detailed pictures under Weighted Centerboard.

[Mark Prouty]

I tested it on a lift... sea trials soon.....

Wow! Fasinating experiment. What ingenuity. I bet you would have been a successful alchemist!

Looking forward the results of the sea trials.

[Erik Hardtle]

Ok.. just go back from the sea... er... river trials...

Powering... seemed to do just fine... was doing 17.5 mph for about an hour... hit a few 1-2 ft waves no banging, seems just as before. Boat seemed to sit a little lower in the water.. as if wife was inside the cabin (175lbs) (she wasn't) or the ballast tank was full (it wasn't)

Sailing... (no water ballast) nothing quantitative.. just a feeling... on a close reach with 10-15 mph winds, heeled slowly... not as quick or sudden as it used to.. felt more like a keel boat heeling... got a heel of up to 30 degrees doing 5.3 mph... didn't round up into the wind like it normally would do. Filled the ballast, less heeling... same "keel boat" feeling with it slowly heeling... not sudden heels.

Hitting bottom: it works like a 'boat brake" I purposely went into shallow water while sailing... boat came to a slow stop... just cranked it up a little and it continued along. The new wire connecting to the board does sing a little while sailing... nothing annoying.

Overall I'm pretty happy with the performance.

[Jeff S]

Impressive. I like the idea-I hope the raising system is up to the task and that you get the stronger bracket like you mentioned. 138# is relatively minor compared to the 1400# ballast, but the location is much lower, probably owing to your performance. I wish we could get some actual test data on something like this.

This mod is beyond my willingness or capabilities to complete, however, so I will have to live vicariously through your experiences Erik.

Jeff

[Phil Marriott]

Hey, great mod! I take it the centreboard is largely hollow - so do you think there is any greater risk of it breaking, now it's got more weight behind it? I would imagine the forces providing that keel boat feeling must be exerting a bit more stress on the board's structure. NB: I'm not an engineer (not even a MacGregor owner - yet!) so I'm not talking from a position of expertise.

cheers
Phil.

[Jeff S]

The thing I might worry about is the bracket, lines (which Erik has upgraded) and the hole through the CB about which it pivots. I can't remember- is there a metal sleeve through the CB pivot point or is it just fiberglass there? If it is just fiberglass it may cause problems. I bet it is easy to lower the CB- How tough is it to get it back up? It doesn't look like you have any extra mechanical advantage to get the weight up.

Jeff S

[mike]

The thing I might worry about is the bracket, lines (which Erik has upgraded) and the hole through the CB about which it pivots. I can't remember- is there a metal sleeve through the CB pivot point or is it just fiberglass there? If it is just fiberglass it may cause problems. I bet it is easy to lower the CB- How tough is it to get it back up? It doesn't look like you have any extra mechanical advantage to get the weight up.

I'm pretty sure that's why he went through the trouble of moving the cable's attachment point aft... looks like that probably adds quite a bit of MA.

--Mike

[Terry]

I like the Mod, especially that you can sail without ballast & perhaps at a faster speed. I've allways wondered about doing a similar mod to the 26M daggerboard, perhaps making the lower half lead or even attaching a lead torpedo to the bottom edge like the Hobie Magic 25 has. Both are a bit complicated but likely doable if one has the time and inclination. Something to design through the years during winter I expect.

[Erik Hardtle]

The centerboard is mostly hollow, there is some foam up near top and solid fiberglass resin on the lead and trailing edges.

Most of the weight is carried by the bracket and the pivot hole attachment... so I did add 4 sheets of fiberglass mat and roving to the trunk where the bracket bolt comes thru. I haven't had the Stainless steel reinforcement made yet ($325 from a metal shop). There is no metal sleeve there now (except for the lead I poured into it... soft metal probably won't help much)... I will be keeping an eye on the pivot hole until I get the reinforcement made.

I did move the attachment point to help with raising and mostly so it would do a better job of keeping it up while powering. I use the existing winch on the deck for cranking it up... it feels like cranking in a genoa with full wind... but it's not bad. I raised and lowered it several time.

I added a few more picture to the website.. click on the WWW button below, go to Mods, then click on Weighted Centerboard.

[bscott]

I did a similar mod to a Hunter 22. Only added 75# of lead. Used brass oar lock bases inserted into a brass tube, thru bolted the oar lock bases together making a very solid mounting for the new thru bolt. Really stiffen up the pointing.

[mikelinmon]

Hi,
Be carefull not to take out the slack in the CB hinge pin. The CB is supposed to wedge itself port or starboard in the cavity. The pin is just a holder, not a fulcrum point! The hole for the pin is much larger than the pin, has to be! I'm thinking the board is strong enough to fill with lead and be safe, but , you are in a new area. Good luck.
Mike Inmon

[pokerrick1]

Is that a record - - - a response to posts SIX YEARS after the last post (I know Mike wasn't a member of this forum until 2007 or thereabouts.

Rick Less

[Jason Carrier]

This long after the mod are you still happy? My 26M is out of the water for the season, I have to repair the dagger board anyway or buy a new one, and was thinking of adding weight. The M heel over very far, and my family does not like it. It kept the m from making some over night trips this summer.

Thanks
Jason

[Divecoz]

Jason .. The Heavy Keel doesn't eliminate heeling, it's the nature of a sailboat to heel "at Times" ..
Just Turn the wheel to point the boat into to the wind, a few degrees.. you'll slow down but she "rights" herself immediately .. or loosen the traveler..Or Reduce sail..With the first two suggestions, Your spilling wind from the sail and there by reducing the force on the boat. The Heavy D.B... reduces tenderness... Allows for sailing more comfortably on "the edge"..

This long after the mod are you still happy? My 26M is out of the water for the season, I have to repair the dagger board anyway or buy a new one, and was thinking of adding weight. The M heel over very far, and my family does not like it. It kept the m from making some over night trips this summer.

Thanks
Jason

[mastreb]

This long after the mod are you still happy? My 26M is out of the water for the season, I have to repair the dagger board anyway or buy a new one, and was thinking of adding weight. The M heel over very far, and my family does not like it. It kept the m from making some over night trips this summer.

Thanks
Jason

Hi Jason--To reduce heel, reef your jib and/or mainsail until the boat is at an angle you like. Heeling more than 20 degrees is not necessary and learning to control it is part of learning to sail.