Heresy

[chipveres]

I'm building a Princess 26. How much trouble will I cause if I leave the centerboard and rudder full thickness, without shaping the airfoil section?

[JeffM]

God loves a cheerful heretic! But may I ask why you want a slab-sided cb and rudder?

[Guest Oyster]

Whats your plans number of the Princess 26? I must look into this a bit further.

[chipveres]

Thank you gents for trying. Plans number 14 GDB. (you can translate that for yourself) I want the strongest possible centerboard because I know by experience I will locate every rock in Biscayne Bay the hard way.

[Gordy Hill]

I've sailed in Biscayne Bay. Those aren't rocks, they're old Chevys.

[Guest Oyster]

There are important reasons for doing so, and its not just one designer doing it. I would contact Graham directly as he is more than receptive in discussing each and every component and its designed capability. I just didn't know if there was some different version or change that differs from his normal parts of other hulls of his design. Thats all. He will normally get back to you in a day.

His landline has always been open, even if you leave a message on his machine. In the early going there are some questions that seems complicated but are not, and should be always asked if thinking about making changes from the intended drawn parts. Good building and post pictures. A lot of folks sit quietly by and watch progress on this forum. This board in known for more building and less talking. So don't be discouraged if you do not receive large and lengthy responses. People do take note. Cheers.

[Garry]

Hi Chip and Welcome.

I share your concern about dinging the c'board and rudder. I wonder if the material for them could be aluminum instead of wood. Or maybe you could add a metal shoe on the bottom portion of them.

If you search the archives, you may find this question (and others) have been discussed before.

Garry

[Garry]

One other idea I have seen posted here is to incorporate a piece of nylon rope hardened with epoxy into the leading edge of the board. There is also the idea of wrapping the leading edge in fiberglass, either over the wood or over the rope edge, to strengthen it.

I think you would lose too much in pointing ability and rudder control with a blunt edge.

Garry

[PAR]

The vast majority of damage to an exposed blade (rudder/dagger/centerboard) will be along the leading edge. Hardening this up, with one of several methods is always a wise thing in shoal waters. The line in epoxy thing, works well on small craft. Vessels that can carry some momentum, when encountering those sunken Chevy's, may want for a harder edge, which can be metal (traditional) or one of the high tech materials available. I like the idea of a shock absorbing material such as polyurethane or polyethylene, maybe even a lead strip, but attachment may prove troublesome with some types of blade construction methods.

As for shape, you wouldn't be hurt very much if the appendages had a well rounded leading edge, with straight sides and an easy taper toward the trailing edge, as opposed to a NACA sectional shape. This would simplify the construction of these foils a bit, with little harm to her abilities.