Re: hollowed vs. birdsmouth vs. box mast
--- Inbolger@yahoogroups.com, "smithriverranger"
<jasonstancil@h...> wrote:
I'm trying to figure out wich route to take on
It has been awhile since I built the spars for my ex-Micro
LESTAT but.....doesn't Bolger already provide exactly the
construction method and dimensions needed for the construction of
your spars with the plans?
As a general rule,an amateur builder can save alot of time,guess
work,worry and chaos by following the information provided in the
plans,especially with a proven design like the MICRO.
One silly advantage of following the instuctions on the plans is
that you"automatically" get a nice little 1/2" square tunnel running
all the way to the top of the mast...great for running wiring for a
mast head light.Beyond that, all you have to do is glue together
some dimesional lumber one morning,plane and trim the next day and
start varnishing on the third day.Tools require?
Clamps,planes,pencils and measuring tape. It doesn't get much easier
then that unless your only tool is an axe and you just chop a tree
down for the mast :-)
If you are new to the beautiful world of boatbuilding,sticking
to the plans can go a long way toward ensuring a successful build.On
the other hand,if you have several boats under your belt,and evolved
preferences for how you like to do/build things,then...ah...wait a
minute....well I guess you wouldn't be puzzling over changes to the
design specs would you?
Bolger,the designer, tells/shows you what his choice is for his
designs while allowing some leeway for various levels of experience
etc.....while here,in the group,you'll get lots of differing
opinions,from all sorts of sources,not all of it first hand either
nor based on experience.Not a bad thing,in and of itself,but just
remember that none of us beer swilling pirates is accountable for
our free advice while Bolger,the designer,is.
Sincerely,
Peter Lenihan,hoping this is not taken all wrong.........
<jasonstancil@h...> wrote:
I'm trying to figure out wich route to take on
> my micro Does theJason,
> diameter need to increase from the plans or can i stick with the
> diameter called for?
It has been awhile since I built the spars for my ex-Micro
LESTAT but.....doesn't Bolger already provide exactly the
construction method and dimensions needed for the construction of
your spars with the plans?
As a general rule,an amateur builder can save alot of time,guess
work,worry and chaos by following the information provided in the
plans,especially with a proven design like the MICRO.
One silly advantage of following the instuctions on the plans is
that you"automatically" get a nice little 1/2" square tunnel running
all the way to the top of the mast...great for running wiring for a
mast head light.Beyond that, all you have to do is glue together
some dimesional lumber one morning,plane and trim the next day and
start varnishing on the third day.Tools require?
Clamps,planes,pencils and measuring tape. It doesn't get much easier
then that unless your only tool is an axe and you just chop a tree
down for the mast :-)
If you are new to the beautiful world of boatbuilding,sticking
to the plans can go a long way toward ensuring a successful build.On
the other hand,if you have several boats under your belt,and evolved
preferences for how you like to do/build things,then...ah...wait a
minute....well I guess you wouldn't be puzzling over changes to the
design specs would you?
Bolger,the designer, tells/shows you what his choice is for his
designs while allowing some leeway for various levels of experience
etc.....while here,in the group,you'll get lots of differing
opinions,from all sorts of sources,not all of it first hand either
nor based on experience.Not a bad thing,in and of itself,but just
remember that none of us beer swilling pirates is accountable for
our free advice while Bolger,the designer,is.
Sincerely,
Peter Lenihan,hoping this is not taken all wrong.........
Hi Roger, This is my recollection of advice given in Bud MacIntosh
article on hollow sparmaking (Woodenboat). That the loads are not
calculated to that precision is reason enough for increasing the
cross-section 10%. Without doing the calculations, 5% of the diameter
is a different number. Secondly adding to the cross-section is
certainly easier than dealing with fiberglas at the partners. Although
we say taper often enough the mast is not tapered straight but has a
curve. A taper jig wont work. Yes the "staves" or whatever would be
cut and "tapered" before assembly.
Bob Chamberland
article on hollow sparmaking (Woodenboat). That the loads are not
calculated to that precision is reason enough for increasing the
cross-section 10%. Without doing the calculations, 5% of the diameter
is a different number. Secondly adding to the cross-section is
certainly easier than dealing with fiberglas at the partners. Although
we say taper often enough the mast is not tapered straight but has a
curve. A taper jig wont work. Yes the "staves" or whatever would be
cut and "tapered" before assembly.
Bob Chamberland
--- Inbolger@yahoogroups.com, "Roger Derby" <derbyrm@s...> wrote:
> I'm not clear as to why a hollow mast needs to be 5% bigger in
diameter. I
> don't think the loads are calculated to that precision and loss of the
> middle doesn't reduce the strength that much. Variations in the
wood will
> swamp out any such changes IMHO. Wrapping the area of the partners with
> fiberglass should eliminate most breakage.
>
> According to the article in Wooden Boat, the tapering is best done by
> tapering the staves before the glue-up. (My sample was untapered.) The
> boatbuilding shop which was shown in the article used a home-made
taper jig
> on their table saw.
>
> Roger
> derbyrm@s...
>http://derbyrm.mystarband.net
>
> ----- Original Message -----
> From: <cha62759@t...>
>
>
> > A hollow round mast is easy and obviously lighter than solid. A box
> > mast is easier and probably about the same weight as hollow round.
> > I've never built a birds mouth mast but it is obviously more
> > complicated-I don't know how much more. It should be lighter. A hollow
> > mast should be about 10% greater in cross-section than a solid mast. A
> > taper is simple. Cut it rough with a skil saw and get out your plane
> > to finish.
> > Bob Chamberland
> >
> > --- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
> > wrote:
> > > Can anyone explain the virtues and vices of hollowed round, bird's
> > > mouth and box masts. I'm trying to figure out wich route to take on
> > > my micro and now that i've bought a router it's opening up these
> > > doors. They all seem simple enough but i'm a hesitant on tapering
> > > the box and bird's mouth masts, those staves are so loooong and hard
> > > enough to rip straight, hateto screw them up trying to taper them.
> > > Other than weight savings are there any benifits to the extra flex
> > > afforded by a tapered mast up high (sprit rig). Been screwing around
> > > making little 2' masts and just don't know what route to take. The
> > > box is easy to rabbet and fit but it will look huge! Does the
> > > diameter need to increase from the plans or can i stick with the
> > > diameter called for?
> > > Anyone?
> > > Jason Stancil
I'm not clear as to why a hollow mast needs to be 5% bigger in diameter. I
don't think the loads are calculated to that precision and loss of the
middle doesn't reduce the strength that much. Variations in the wood will
swamp out any such changes IMHO. Wrapping the area of the partners with
fiberglass should eliminate most breakage.
According to the article in Wooden Boat, the tapering is best done by
tapering the staves before the glue-up. (My sample was untapered.) The
boatbuilding shop which was shown in the article used a home-made taper jig
on their table saw.
Roger
derbyrm@...
http://derbyrm.mystarband.net
don't think the loads are calculated to that precision and loss of the
middle doesn't reduce the strength that much. Variations in the wood will
swamp out any such changes IMHO. Wrapping the area of the partners with
fiberglass should eliminate most breakage.
According to the article in Wooden Boat, the tapering is best done by
tapering the staves before the glue-up. (My sample was untapered.) The
boatbuilding shop which was shown in the article used a home-made taper jig
on their table saw.
Roger
derbyrm@...
http://derbyrm.mystarband.net
----- Original Message -----
From: <cha62759@...>
> A hollow round mast is easy and obviously lighter than solid. A box
> mast is easier and probably about the same weight as hollow round.
> I've never built a birds mouth mast but it is obviously more
> complicated-I don't know how much more. It should be lighter. A hollow
> mast should be about 10% greater in cross-section than a solid mast. A
> taper is simple. Cut it rough with a skil saw and get out your plane
> to finish.
> Bob Chamberland
>
> --- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
> wrote:
> > Can anyone explain the virtues and vices of hollowed round, bird's
> > mouth and box masts. I'm trying to figure out wich route to take on
> > my micro and now that i've bought a router it's opening up these
> > doors. They all seem simple enough but i'm a hesitant on tapering
> > the box and bird's mouth masts, those staves are so loooong and hard
> > enough to rip straight, hateto screw them up trying to taper them.
> > Other than weight savings are there any benifits to the extra flex
> > afforded by a tapered mast up high (sprit rig). Been screwing around
> > making little 2' masts and just don't know what route to take. The
> > box is easy to rabbet and fit but it will look huge! Does the
> > diameter need to increase from the plans or can i stick with the
> > diameter called for?
> > Anyone?
> > Jason Stancil
A hollow round mast is easy and obviously lighter than solid. A box
mast is easier and probably about the same weight as hollow round.
I've never built a birds mouth mast but it is obviously more
complicated-I don't know how much more. It should be lighter. A hollow
mast should be about 10% greater in cross-section than a solid mast. A
taper is simple. Cut it rough with a skil saw and get out your plane
to finish.
Bob Chamberland
--- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
wrote:
mast is easier and probably about the same weight as hollow round.
I've never built a birds mouth mast but it is obviously more
complicated-I don't know how much more. It should be lighter. A hollow
mast should be about 10% greater in cross-section than a solid mast. A
taper is simple. Cut it rough with a skil saw and get out your plane
to finish.
Bob Chamberland
--- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
wrote:
> Can anyone explain the virtues and vices of hollowed round, bird's
> mouth and box masts. I'm trying to figure out wich route to take on
> my micro and now that i've bought a router it's opening up these
> doors. They all seem simple enough but i'm a hesitant on tapering
> the box and bird's mouth masts, those staves are so loooong and hard
> enough to rip straight, hateto screw them up trying to taper them.
> Other than weight savings are there any benifits to the extra flex
> afforded by a tapered mast up high (sprit rig). Been screwing around
> making little 2' masts and just don't know what route to take. The
> box is easy to rabbet and fit but it will look huge! Does the
> diameter need to increase from the plans or can i stick with the
> diameter called for?
> Anyone?
> Jason Stancil
Making the cuts for a mast isn't that hard if your using a table
saw. If you don't have one rent one or borrow it doesn't take much
of a Saw to cut them. You can cut the beaks with a table saw also.
use an old innertube for clamps. Try a small spar first and see what
you think. I won't build anything but a birds mouth from now on. You
can even taper them if you want to. JWK
--- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
wrote:
saw. If you don't have one rent one or borrow it doesn't take much
of a Saw to cut them. You can cut the beaks with a table saw also.
use an old innertube for clamps. Try a small spar first and see what
you think. I won't build anything but a birds mouth from now on. You
can even taper them if you want to. JWK
--- Inbolger@yahoogroups.com, "smithriverranger" <jasonstancil@h...>
wrote:
> Can anyone explain the virtues and vices of hollowed round, bird'shard
> mouth and box masts. I'm trying to figure out wich route to take on
> my micro and now that i've bought a router it's opening up these
> doors. They all seem simple enough but i'm a hesitant on tapering
> the box and bird's mouth masts, those staves are so loooong and
> enough to rip straight, hateto screw them up trying to taper them.around
> Other than weight savings are there any benifits to the extra flex
> afforded by a tapered mast up high (sprit rig). Been screwing
> making little 2' masts and just don't know what route to take. The
> box is easy to rabbet and fit but it will look huge! Does the
> diameter need to increase from the plans or can i stick with the
> diameter called for?
> Anyone?
> Jason Stancil
Can anyone explain the virtues and vices of hollowed round, bird's
mouth and box masts. I'm trying to figure out wich route to take on
my micro and now that i've bought a router it's opening up these
doors. They all seem simple enough but i'm a hesitant on tapering
the box and bird's mouth masts, those staves are so loooong and hard
enough to rip straight, hateto screw them up trying to taper them.
Other than weight savings are there any benifits to the extra flex
afforded by a tapered mast up high (sprit rig). Been screwing around
making little 2' masts and just don't know what route to take. The
box is easy to rabbet and fit but it will look huge! Does the
diameter need to increase from the plans or can i stick with the
diameter called for?
Anyone?
Jason Stancil
mouth and box masts. I'm trying to figure out wich route to take on
my micro and now that i've bought a router it's opening up these
doors. They all seem simple enough but i'm a hesitant on tapering
the box and bird's mouth masts, those staves are so loooong and hard
enough to rip straight, hateto screw them up trying to taper them.
Other than weight savings are there any benifits to the extra flex
afforded by a tapered mast up high (sprit rig). Been screwing around
making little 2' masts and just don't know what route to take. The
box is easy to rabbet and fit but it will look huge! Does the
diameter need to increase from the plans or can i stick with the
diameter called for?
Anyone?
Jason Stancil