Re: Dagger Board Slots
Hi Dennis, A couple of approaches you might consider. First, if you
are glassing the bottom, is to fold the glass into the daggerboard
case covering the end grain. The second is to use the technique
illustrated in the Gougeons book on boat construction. I'm not sure I
can explain it however. Cut the slot leaving a gap between the case
and the hull bottom stringer. Set the case in place and then fill the
gap with epoxy with silicon filler. The trimaran I built years ago was
done in this manner and nothing was going to damage that joint. I also
glassed the insides of the case before installation. I never never had
a centerboard case leak.
Bob Chamberland
are glassing the bottom, is to fold the glass into the daggerboard
case covering the end grain. The second is to use the technique
illustrated in the Gougeons book on boat construction. I'm not sure I
can explain it however. Cut the slot leaving a gap between the case
and the hull bottom stringer. Set the case in place and then fill the
gap with epoxy with silicon filler. The trimaran I built years ago was
done in this manner and nothing was going to damage that joint. I also
glassed the insides of the case before installation. I never never had
a centerboard case leak.
Bob Chamberland
--- In bolger@y..., "pseudodion42" <pseudodion3@a...> wrote:
> Hi, all.
> I have cut the dagger board slot in the hull. Does one line the
> slot with glass, or simply seal the end grain with epoxy?
>
> Thanks,
>
> Dennis
I have a hard time believing it doesn't cause more drag during level
displacement operations, but I will never have built the boat to find
out. Seems like a rot disaster waiting to happen. It is one of his
older details, and I am not convinced that using a good wood that
would last out there is a cheap solution these days. It isn't any
easier for me to build that way. On a Tennessee, the sides are plumb
so there isn't any bevel, but with a bevel, it still doesn't seem any
easier, you have a number of options, none of which is what I would
call hard. I know PCB has praised the fact the interior is easier to
keep clean, but if that were my concern I would just hit it with a
big cove. Of course his view preceeds the eminense of epoxy, so I am
not contradicting it, I just don't allow myself to be affected by it.
displacement operations, but I will never have built the boat to find
out. Seems like a rot disaster waiting to happen. It is one of his
older details, and I am not convinced that using a good wood that
would last out there is a cheap solution these days. It isn't any
easier for me to build that way. On a Tennessee, the sides are plumb
so there isn't any bevel, but with a bevel, it still doesn't seem any
easier, you have a number of options, none of which is what I would
call hard. I know PCB has praised the fact the interior is easier to
keep clean, but if that were my concern I would just hit it with a
big cove. Of course his view preceeds the eminense of epoxy, so I am
not contradicting it, I just don't allow myself to be affected by it.
In a small boat, the external chines make it easier to keep the
interior clean. I suspect PCB used them in Tennessee for ease of
construction.
interior clean. I suspect PCB used them in Tennessee for ease of
construction.
I can't speak to the behaivior of water molecules, but external
chines are easier to fit. They also make nice toe holds for
climbing back into the boat (a Teal in my case.)
I don't notice any difference in the ability of my Teal (external) vs.
my Scooner (internal) to go to weather without their boards
down. The sharp chine seems equally effective, or ineffective.
I suspect that in most cases the difference in performance is
minimal and it's more a matter of taste and ease of building.
chines are easier to fit. They also make nice toe holds for
climbing back into the boat (a Teal in my case.)
I don't notice any difference in the ability of my Teal (external) vs.
my Scooner (internal) to go to weather without their boards
down. The sharp chine seems equally effective, or ineffective.
I suspect that in most cases the difference in performance is
minimal and it's more a matter of taste and ease of building.
--- In bolger@y..., <boatbuilding@g...> wrote:
> Is there any advantage to external chines? The Tennessee is
> built with an external chine made of two layers of 1x2 rounded
> off. I liked the idea of the external chine protecting the
> boat but have heard several theories for and against pertaining
> to water flow and verticle sided boats. I don't mind the looks
> since 90% or more is underwater and not seen. Some say
that it
> helps reduce the high pressure difference between the side
and
> hull bottom, others say it causes more turbulance.
>
> I've just jacked up the boat to finish the chines and am
> curious why Bolger uses both.
>
> Jeff
Is there any advantage to external chines? The Tennessee is
built with an external chine made of two layers of 1x2 rounded
off. I liked the idea of the external chine protecting the
boat but have heard several theories for and against pertaining
to water flow and verticle sided boats. I don't mind the looks
since 90% or more is underwater and not seen. Some say that it
helps reduce the high pressure difference between the side and
hull bottom, others say it causes more turbulance.
I've just jacked up the boat to finish the chines and am
curious why Bolger uses both.
Jeff
built with an external chine made of two layers of 1x2 rounded
off. I liked the idea of the external chine protecting the
boat but have heard several theories for and against pertaining
to water flow and verticle sided boats. I don't mind the looks
since 90% or more is underwater and not seen. Some say that it
helps reduce the high pressure difference between the side and
hull bottom, others say it causes more turbulance.
I've just jacked up the boat to finish the chines and am
curious why Bolger uses both.
Jeff
--- In bolger@y..., David Ryan <david@c...> wrote:
and the lumber for and aft ends where also glassed. The outside of
the box was glassed with more biax on the corners. the whole thing
was tabbed to the bottom with biaxial, and the inside base had large
fillets and more biax. The top was tabbed into the cabin floor.
Those are petty typical details if you want long lasting leak-proof
performance. This boat is about 800#, and carries 250 square feet of
sail. It has about a 4' board, and could operate at highish tri
speeds. There are foam crash blocks. Your mileage may vary.
> >Hi, all.the
> > I have cut the dagger board slot in the hull. Does one line
> >slot with glass, or simply seal the end grain with epoxy?On my tri, the ply sides, where glassed with 10 oz on the inside,
and the lumber for and aft ends where also glassed. The outside of
the box was glassed with more biax on the corners. the whole thing
was tabbed to the bottom with biaxial, and the inside base had large
fillets and more biax. The top was tabbed into the cabin floor.
Those are petty typical details if you want long lasting leak-proof
performance. This boat is about 800#, and carries 250 square feet of
sail. It has about a 4' board, and could operate at highish tri
speeds. There are foam crash blocks. Your mileage may vary.
>Hi, all.My Scooner has a dagger board, and since it wasn't much trouble I
> I have cut the dagger board slot in the hull. Does one line the
>slot with glass, or simply seal the end grain with epoxy?
went ahead and glassed the inner side of the plywood before
gluing/screwing the thing together. It leaked anyway.
In my experience, glass/epoxy/paint protection is most important
where the surface is exposed to sunlight. In places where the sun
don't shine, paint alone or even bare wood have held up pretty well.
YIBB,
David
C.E.P.
415 W.46th Street
New York, New York 10036
http://www.crumblingempire.com
Mobile (646) 325-8325
Office (212) 247-0296
Hi, all.
I have cut the dagger board slot in the hull. Does one line the
slot with glass, or simply seal the end grain with epoxy?
Thanks,
Dennis
I have cut the dagger board slot in the hull. Does one line the
slot with glass, or simply seal the end grain with epoxy?
Thanks,
Dennis