Re: [bolger] daggerboard strength
Some of the multihulls have styrofoam tips on the daggerboards. If you hit
bottom, the tip (maybe 1 to 2 feet of a 5-foot board) is sacrificed and you
have a repair to do, but the board still works and it didn't wreck the
trunk.
Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing
bottom, the tip (maybe 1 to 2 feet of a 5-foot board) is sacrificed and you
have a repair to do, but the board still works and it didn't wreck the
trunk.
Don Hodges
dhodges@...
http://www.ecoastlife.com
Your Cyber-Vacation - Loafing on the Emerald Coast
Small Boats, Building, Fishing, Paddling, Rowing, Sailing
----- Original Message -----
From: Lincoln Ross <lincolnr@...>
To: <bolger@egroups.com>
Sent: Saturday, May 27, 2000 2:06 PM
Subject: [bolger] daggerboard strength
> Recently acquired a fiberglass dinghy because I felt too gimpy at the
> moment to work on my projects and I didn't want to miss the sailing
> season. The daggerboard is fine, but the daggerboard trunk has had
> quite a bit of damage. Has anyone ever built daggerboards that were
> weakened in the fore and aft direction but not sideways, so that if
> you hit a rock the board and not the trunk fails? Doesn't seem like
> this would be all that hard to do. Seems like you could make them
> just
> a bit thicker, and then put a saw kerf at the front and back, leaving
> maybe a third of the board intact, at the thickest point. Then you
> could fill in with something that had no strength. Alternatively,
> you could put in a bunch of vertical cuts so that you have a
> bunch of shallow beams instead of one deep beam in the fore and
> aft direction. Maybe someone else has a better idea?
>
>
> ------------------------------------------------------------------------
> Old school buds here:
>http://click.egroups.com/1/4057/10/_/3457/_/959454403/
> ------------------------------------------------------------------------
>
>
>
This is rarely done. What is done, especially on high speed catamarans, is
to build a "crush box". The case is longer so that grounding forces the
dagger board back into the "crush box" and doesn't impair the watertight
integrity.
Paul W. Esterle
Capt'n Pauley Video Productions
423.989.3159
S/V Bryn Awel, Columbia 10.7
Bristol, Tenn. USA
http://www.captnpauley.bigstep.com
http://pages.preferred.com/~pesterle/
to build a "crush box". The case is longer so that grounding forces the
dagger board back into the "crush box" and doesn't impair the watertight
integrity.
Paul W. Esterle
Capt'n Pauley Video Productions
423.989.3159
S/V Bryn Awel, Columbia 10.7
Bristol, Tenn. USA
http://www.captnpauley.bigstep.com
http://pages.preferred.com/~pesterle/
----- Original Message -----
From: Lincoln Ross <lincolnr@...>
To: <bolger@egroups.com>
Sent: Saturday, May 27, 2000 3:06 PM
Subject: [bolger] daggerboard strength
> Recently acquired a fiberglass dinghy because I felt too gimpy at the
> moment to work on my projects and I didn't want to miss the sailing
> season. The daggerboard is fine, but the daggerboard trunk has had
> quite a bit of damage. Has anyone ever built daggerboards that were
> weakened in the fore and aft direction but not sideways, so that if
> you hit a rock the board and not the trunk fails? Doesn't seem like
> this would be all that hard to do. Seems like you could make them
> just
> a bit thicker, and then put a saw kerf at the front and back, leaving
> maybe a third of the board intact, at the thickest point. Then you
> could fill in with something that had no strength. Alternatively,
> you could put in a bunch of vertical cuts so that you have a
> bunch of shallow beams instead of one deep beam in the fore and
> aft direction. Maybe someone else has a better idea?
>
>
> ------------------------------------------------------------------------
> Old school buds here:
>http://click.egroups.com/1/4057/10/_/3457/_/959454403/
> ------------------------------------------------------------------------
>
>
--- Inbolger@egroups.com, "Chuck Leinweber" <chuck@d...> wrote:
steel strap. The connection held in
This
one is raked, or at least the board is. THere's apparently nothing to
hold it down, but the damage is very apparent. Maybe the real trick
is
to rake the trunk the other way (bottom towards front)? Or maybe the
bottom has no rocks where you sail? Anyway, thanks for the idea. I am
thinking of doing a leeboard someday to avoid heavy structural glass
work.
> Lincoln:snip how to keep the dagger board down, snip two strip magnets snip
>
steel strap. The connection held in
> all sailing conditions, but the slightest bump on the bottom of theboard
> sent it floating up in the trunk. snipI suspect your daggerboard trunk was straight up and down, maybe?
This
one is raked, or at least the board is. THere's apparently nothing to
hold it down, but the damage is very apparent. Maybe the real trick
is
to rake the trunk the other way (bottom towards front)? Or maybe the
bottom has no rocks where you sail? Anyway, thanks for the idea. I am
thinking of doing a leeboard someday to avoid heavy structural glass
work.
Lincoln:
I once built a small pram with a sailing rig. The plans were unclear about
how to keep the dagger board down, so I dreamed up this method: I used one
of those two strip magnets that you can find in hobby supply stores, and a
couple of pieces of 1/2" x 1/8" mild steel strap. The connection held in
all sailing conditions, but the slightest bump on the bottom of the board
sent it floating up in the trunk. I hit the bottom a lot, without any
damage at all.
Chuck
I once built a small pram with a sailing rig. The plans were unclear about
how to keep the dagger board down, so I dreamed up this method: I used one
of those two strip magnets that you can find in hobby supply stores, and a
couple of pieces of 1/2" x 1/8" mild steel strap. The connection held in
all sailing conditions, but the slightest bump on the bottom of the board
sent it floating up in the trunk. I hit the bottom a lot, without any
damage at all.
Chuck
> Recently acquired a fiberglass dinghy because I felt too gimpy at the
> moment to work on my projects and I didn't want to miss the sailing
> season. The daggerboard is fine, but the daggerboard trunk has had
> quite a bit of damage. Has anyone ever built daggerboards that were
> weakened in the fore and aft direction but not sideways, so that if
> you hit a rock the board and not the trunk fails? Doesn't seem like
> this would be all that hard to do. Seems like you could make them
> just
> a bit thicker, and then put a saw kerf at the front and back, leaving
> maybe a third of the board intact, at the thickest point. Then you
> could fill in with something that had no strength. Alternatively,
> you could put in a bunch of vertical cuts so that you have a
> bunch of shallow beams instead of one deep beam in the fore and
> aft direction. Maybe someone else has a better idea?
>
>
> ------------------------------------------------------------------------
> Old school buds here:
>http://click.egroups.com/1/4057/10/_/3457/_/959454403/
> ------------------------------------------------------------------------
>
>
>