centreboard conversion

Hello, new boy here. Old new boy.

I recently got my mirror (37428) which I intend to use as my personal sail training vessel, initially on a lake. Eventually I plan to use it on the coast (Wales). I have "form" sailing and rowing, but long, long ago. I have no interest in Mirror class competition, and little in cosmetics.

Weeks of spare time have been spent on learning how to repair the rotten bits, of which there are several. It would have been simpler to buy a better boat, but I love work much more than spending money. Some of the expenses have been defrayed by selling ancillaries, so the project has a pleasingly low standing-in value.

Now both the large bottom panels and the daggerboard case need replacing and I wondered about making a centreboard conversion instead as a safety measure - so many minor accidents appear to involve the daggerboard colliding with something or otherwise being a nuisance. There is a Youtube video of a converted dinghy which helps a little, but the views of someone who has actually done it would be very valuable.

Can you help?

curlew's picture

I have done this and I could send you a diagram if you want. How do I send the picture|??

Hello David. I follow your you tube channel with great interest. I have copied a few of your mirror mods to my recent purchase but I want to do the pivoting centreboard. do you have any drawings I could use? Or any photos of the conversion in progress would help.
My email is ratatat.tat61@gmail.com.

Hope you don't mind me asking many thanks Craig

I don't know how to post pics on the forum, but you could put them in some public place and post a link, or send to me using my username at yahoo dot com. Gernot will know how to do it, as he has posted pics. Rgds, Chris

62816inBerlin's picture

The gent who runs the YouTube Channel http://www.youtube.com/user/msf60khz has converted his Mirror to a swing-centreboard, perhaps you can short-circuit communications with him.
He has done video clips of his modifications, e. g. at http://www.youtube.com/watch?v=R1Ny7r9P5OQ .
Showing pictures here is possible, but because I'm running the site on an amateur basis and shoestring budget, we have limited space to put the files, so if you can, place them elsewhere and link them here as described for the tag.
I posted some pictures of my repairs to the centreboard trunk last year, but have stuck to the conventional pattern. Hit a rock on this year's JollenFlottille but not at full speed and the board survived.
Remember that a swing centreboard will mean less room in the cockpit, though.
Have fun,


P.S. my centreboard trunk repairs are documented in another thread here : http://forum.mirrordiscussforum.org/comment/123#comment-123

Thanks Gernot, I understand about the bandwidth - just got a $65 bill for overrun on one of mine.

It seemed almost radical to take a "health & safety" view of a boat which is used for fun, but it occurs to me that removing hazards is a normal part of seamanship. This issue is one which is often written about in the context of cruising and I have a suspicion that once I have completed it, I will get away with being in harm's way for longer!

You will be out of class and not be able to compete in serious Mirror Dinghy regattas.

One who has never worried about being out of class or a serious racer.

Not so, Pete! Only the boat will be OOC, not me!

You got me really good on that one.

While waiting for the appropriate conjunction of funds and weather to re-bottom my boat and add the centreboard, any number of ideas bubbled to the surface. Ruining a Mirror is not the motivation, but might well be the result of most of them.

First up was "try chine runners, instead of the daggerboard/centreboard".

Anyone thought about that?

BTW Gernot, I strongly suspect that http://www.youtube.com/user/msf60khz is amongst us, very close in fact.

62816inBerlin's picture

As far as I have understood, chine runners work like the asymmetrical hull of a proa, i.e. the curvature provides the forces counteracting the lateral forces on the mainsail. Even without chine runners, you can control the direction of a Mirror by heeling it oene way or another (I tried that yesterday in another context*). However, if you are sailing the boat fairly upright (which is the fastest way to go) both chine runners will be in the water with a "toe-in" effect and act as brakes. It would take some pretty compicated fluid dynamics calculations / simulations to find out whether they would really be a useful alternative to a centreboard. If you're prepared to mess about with the design and looking for more room in the cockpit, lee boards would also be worth discussing, but the trade-off is more weight and an extra job to do when going about (assuming you pull up the windward board).
Gernot H.

*Seeing how long I could stand in the cockpit with the tiller held by a bungee without the boat gybing or going off course. I'm still toying with the idea of buying a spinnaker.

PuffinInTegel's picture

Quote : "I recently got my mirror (37428) which I intend to use as my personal sail training vessel, initially on a lake. " unquote.

Would you like your boat to be added to the Roll Call?

Gernot H.

Hi Gernot,
I see you are toying with the idea of buying a spinnaker. It is a neat sail, but not the easiest to handle. But when used properly does increase the speed.
When I used mine I added a system which held the rudder in a fixed position because when raising or lowering the spinnaker single handedly one needs both hands to do it.

In the interest of personal safety, I decided last year to stop using my spinnaker considering that I am getting a little long in the tooth. But I bet it will not be too many years before my grand daughter talks me into putting it back in my Mirror.