Re: Mast Construction
--
Thanks for the very good comments. Someday, I would like to try the
art of "Birdseye" mast construction. That has got to be the most
eloquent way to do a mast. And, there is certainly something to be
said for the stand-alone tree. I have made my decision and Edensaw
has come through with solid, air dry, vertical grain, clear, straight
sticks for me. Now, if I can do justice with my limited wood working
skills to turn those sticks into working spars...
Regards,
Dennis
- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@...> wrote:
Thanks for the very good comments. Someday, I would like to try the
art of "Birdseye" mast construction. That has got to be the most
eloquent way to do a mast. And, there is certainly something to be
said for the stand-alone tree. I have made my decision and Edensaw
has come through with solid, air dry, vertical grain, clear, straight
sticks for me. Now, if I can do justice with my limited wood working
skills to turn those sticks into working spars...
Regards,
Dennis
- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@...> wrote:
>
> On 10/10/06, Harry James wrote:
>
> > HJ
> > 82 NM from Sitka with a wood shed full of spruce.
>
>
> As George Buehler would advocate,
>
> If you live in a place with bad wood for spars, relocate to a place
> with good wood for spars.
>
> Remember, we are talking about a 12 foot long Old Shoe. Indeed, a
> roughcut 4x4 would work!
>
On 10/10/06, Harry James wrote:
If you live in a place with bad wood for spars, relocate to a place
with good wood for spars.
Remember, we are talking about a 12 foot long Old Shoe. Indeed, a
roughcut 4x4 would work!
> HJAs George Buehler would advocate,
> 82 NM from Sitka with a wood shed full of spruce.
If you live in a place with bad wood for spars, relocate to a place
with good wood for spars.
Remember, we are talking about a 12 foot long Old Shoe. Indeed, a
roughcut 4x4 would work!
Info from another list
Wood has just one problem; because wood cells are long, thin-walled
tubes, they are very prone to buckling, just like drinking straws.
This means that wood is only about half as strong when compressed as
when stretched, as the cells tend to fail along a so-called
compression crease. If a wooden rod is bent, the compression crease
will form on the concave side. This will subsequently weaken the rod.
Trees prevent this happening to their trunks and branches by
pre-stressing them.
New wood cells are laid down on the outside of the trunk in a fully
hydrated state. As they mature their cell walls dry out and this tends
to make them shorten. However, because they are already attached to
the wood inside they cannot shrink and will be held in tension.
Because this happens to each new layer of cells, the outer part of the
trunk is held in tension, while the inside of the trunk is held in
compression. The advantage of this is that when the tree is bent over
by the wind, the wood cells on the surface are not actually compressed
but some of the pre-tension is released. On the other, convex side the
cells will be subjected to even greater tensile forces, but they can
cope very easily with those. The consequence is that tree trunks can
bend a long way without breaking. This fact was exploited for
centuries by shipwrights who made their masts, as far as possible,
from complete tree trunks.
From:
http://www.nhm.ac.uk/nature-online/life/plants-fungi/Fathomseminar-treesmagnificentstructures/session3/no-plant-fathomseminar-trees-session3.html
donschultz8275 wrote:
Wood has just one problem; because wood cells are long, thin-walled
tubes, they are very prone to buckling, just like drinking straws.
This means that wood is only about half as strong when compressed as
when stretched, as the cells tend to fail along a so-called
compression crease. If a wooden rod is bent, the compression crease
will form on the concave side. This will subsequently weaken the rod.
Trees prevent this happening to their trunks and branches by
pre-stressing them.
New wood cells are laid down on the outside of the trunk in a fully
hydrated state. As they mature their cell walls dry out and this tends
to make them shorten. However, because they are already attached to
the wood inside they cannot shrink and will be held in tension.
Because this happens to each new layer of cells, the outer part of the
trunk is held in tension, while the inside of the trunk is held in
compression. The advantage of this is that when the tree is bent over
by the wind, the wood cells on the surface are not actually compressed
but some of the pre-tension is released. On the other, convex side the
cells will be subjected to even greater tensile forces, but they can
cope very easily with those. The consequence is that tree trunks can
bend a long way without breaking. This fact was exploited for
centuries by shipwrights who made their masts, as far as possible,
from complete tree trunks.
From:
http://www.nhm.ac.uk/nature-online/life/plants-fungi/Fathomseminar-treesmagnificentstructures/session3/no-plant-fathomseminar-trees-session3.html
donschultz8275 wrote:
> With care in tree choice, what Bruce suggest is a very good mast. My[Non-text portions of this message have been removed]
> primary hobby is archery. When one uses such a stick as a bow, it is
> called a "self bow". The implication being it is by nature a bow.
> Strength is quite good.
>
> Don
>
> --- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@...> wrote:
>
>> On 10/10/06, Nels <arvent@...> wrote:
>>
>>
>>> One might consider birdsmouth construction:
>>>
>> Or, you could go 'cut stick', that is:
>> Find a small tree, trim off the limbs.
>>
>
>
>
>
If you are not using a tree for a mast then you are better off
laminating. Even if I have a hunk of wood that is the correct size I
will cut it in half and end for end one piece and glue it back up. This
makes sure that no undetected defect goes all the way through and helps
combat any tendency to warp.
HJ
82 NM from Sitka with a wood shed full of spruce.
lancasterdennis wrote:
laminating. Even if I have a hunk of wood that is the correct size I
will cut it in half and end for end one piece and glue it back up. This
makes sure that no undetected defect goes all the way through and helps
combat any tendency to warp.
HJ
82 NM from Sitka with a wood shed full of spruce.
lancasterdennis wrote:
> I am faced with building the masts for my Old Shoe. I have placed an
> order for Sitka Spruce through Edensaw in Port Townsend, Wa.
>
> My question to you dear folks is... would it be better to laminate
> those masts with two sticks or go for a solid stick?
>
> Regards,
>
> Dennis Lancaster
>
>
>
>
>
> Bolger rules!!!
> - NO "GO AWAY SPAMMER!" posts!!! Please!
> - no cursing, flaming, trolling, spamming, respamming, or flogging dead horses
> - stay on topic, stay on thread, punctuate, no 'Ed, thanks, Fred' posts
> - Pls add your comments at the TOP, SIGN your posts, and snip away
> - Plans: Mr. Philip C. Bolger, P.O. Box 1209, Gloucester, MA, 01930, Fax: (978) 282-1349
> - Unsubscribe:bolger-unsubscribe@yahoogroups.com
> - Open discussion:bolger_coffee_lounge-subscribe@yahoogroups.com
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
>
>
With care in tree choice, what Bruce suggest is a very good mast. My
primary hobby is archery. When one uses such a stick as a bow, it is
called a "self bow". The implication being it is by nature a bow.
Strength is quite good.
Don
primary hobby is archery. When one uses such a stick as a bow, it is
called a "self bow". The implication being it is by nature a bow.
Strength is quite good.
Don
--- Inbolger@yahoogroups.com, "Bruce Hallman" <bruce@...> wrote:
>
> On 10/10/06, Nels <arvent@...> wrote:
>
> > One might consider birdsmouth construction:
>
> Or, you could go 'cut stick', that is:
> Find a small tree, trim off the limbs.
On 10/10/06, Nels <arvent@...> wrote:
Find a small tree, trim off the limbs.
> One might consider birdsmouth construction:Or, you could go 'cut stick', that is:
Find a small tree, trim off the limbs.
This link also contains some info on making a birdsmouth tabernacle as
well.
http://members.ozemail.com.au/~storerm/DavidCatboat/davidcatboat.html
Nels
well.
http://members.ozemail.com.au/~storerm/DavidCatboat/davidcatboat.html
Nels
--- Inbolger@yahoogroups.com, "lancasterdennis" <dlancast@...> wrote:
http://watersideboats.com/bolger/
Or google birdsmouth masts.
Nels
>One might consider birdsmouth construction:
> I am faced with building the masts for my Old Shoe. I have placed an
> order for Sitka Spruce through Edensaw in Port Townsend, Wa.
>
> My question to you dear folks is... would it be better to laminate
> those masts with two sticks or go for a solid stick?
>
> Regards,
>
> Dennis Lancaster
>
http://watersideboats.com/bolger/
Or google birdsmouth masts.
Nels
2, or more, laminations will reduce the likelihood of warp.
lancasterdennis wrote:
lancasterdennis wrote:
> I am faced with building the masts for my Old Shoe. I have placed an
> order for Sitka Spruce through Edensaw in Port Townsend, Wa.
>
> My question to you dear folks is... would it be better to laminate
> those masts with two sticks or go for a solid stick?
>
> Regards,
>
> Dennis Lancaster
>
>
I am faced with building the masts for my Old Shoe. I have placed an
order for Sitka Spruce through Edensaw in Port Townsend, Wa.
My question to you dear folks is... would it be better to laminate
those masts with two sticks or go for a solid stick?
Regards,
Dennis Lancaster
order for Sitka Spruce through Edensaw in Port Townsend, Wa.
My question to you dear folks is... would it be better to laminate
those masts with two sticks or go for a solid stick?
Regards,
Dennis Lancaster