Is it a keel or is it a fin?

In a word, either. 

I use keel simply because I always have, like mode 1 on my radios.

Gary gives us comprehensive instructions about this item and in my experience of following such, and how my boats perform, stick to it!.

When talking about the keel you will invariably see  mention the keel (or fin) box.

Make no mistake about this, the box and the keel MUST fit together properly and the box must then bit fitted to the hull as described.

It is best to cut out the keel first then make the box to fit around it, and this don\e before you fit the box to the hull.

When complete, the keel/bulb unit must (go all the way to the box cover and stop there, the supporting bolt holes need to be sitting there , waiting for you to place the locking bolts without  a lot of fiddling about. It is therefore sensible to do this while the box is not permanently glued into the hull.

I just do it this way and then “tack” the box into the hull lightly while I check the alignment of everything to the hull.

That is another post, yet to be added..

 

In the meantime if you have any hints, ideas or solutions please use the contact form to let me know.

2 comments on “Is it a keel or is it a fin?

  1. Fin Trunk / Fin & Rudder alignment

    I’ve heard from some folks concerned about the loose fit of the fin in its’ trunk as they struggle to assure that the rudder is in perfect alignment with the fin.

    The generous clearance of the fin in the trunk is just to insure that the fin will never get stuck and will be easy to install or remove. The trunk with its’ 1/4” opening could accommodate a 3/16” thick fin as well, but 1/8” is all Emma really needs. The resulting play is not a problem in any way. When she is on one tack, the fin will lie to one side, and on the other tack, to the other side.

    Contrary to what some may say, precise alignment of the fin to rudder is NOT an issue. If the fin trunk is fitted to the bulkheads as shown on the plans, and the rudder post is reasonably close to vertical, all will be fine.

    Just before launching, eyeball the rudder and use the trim adjustment on the transmitter to center the rudder position. The boat will travel a course according to the fin, and you, the ever vigilant helmsman, will use the rudder (steering) to make changes or adjustments to that course.

    Cheers, Gary

  2. Hi Everybody,
    I’ve tried out some variations on Emma’s fin / bulb and would like to share what I have learned.

    The first (longest) is made as described on the plans, tried and proven.

    A mid length fin is minus 3 inches (7.6 cm) and weighs 1/2 pound (.23 kg) less. I had hopes that being lighter and with less wetted surface, it would improve performance in light wind. I sailed 2 Emmas together, swapping fins, and was unable to observe any real difference in speed.

    The shortest fin is minus 6 inches (15.2 cm) and is 1 pound (.45 kg) heavier, bringing total boat weight to 14 – 1/2 pounds (6.6 kg). This was done to allow Emma to sail in a shallow pond, and was deemed a success. Handling and stability and speed seemed ok, but I suggest this version only if you must sail in a pond which cannot accommodate Emma’s normal 20 inch (50.8 cm) draft.

    Cheers, Gary

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