Re: [bolger] Re: Micro mast & plywood questions
In a message dated 02/14/2001 11:<BR04:<BR02 PM
Eastern Standard,jboatguy@...writes:
One place for confusion is the taper. Stavbes can be tapered in width or
thickness or both. You seem to be talking about tapering the width only. An
earlier post seemed to be tapering the thickness. Did I misunderstand the
earlier? Do you taper only width?
Cheers/Carron
Eastern Standard,jboatguy@...writes:
> Birdsmouth is SIMPLE; talking about it is complicated.Boy, I'll agree with the last bit :-)
One place for confusion is the taper. Stavbes can be tapered in width or
thickness or both. You seem to be talking about tapering the width only. An
earlier post seemed to be tapering the thickness. Did I misunderstand the
earlier? Do you taper only width?
Cheers/Carron
No way--keep to the sailboat!
Birdsmouth is SIMPLE; talking about it is complicated. Check out the
birdsmouth folder I put in the files. I highly recomend doing the
taper after cuttting the birdsmouth. Running long, thin, tapering
staves through a tablesaw can be problematic, at best, dangerous at
worst, and cutting the taper is easy enough one (or several) at a
time for one mast, even after you've cut the birdsmouth.
After you've cut the birdsmouth, cut the taper from the width of the
stave (width of staves goes around the circumference of mast) on the
side opposite the birdsmouth. The staves all just end up bending in
slightly, making the taper. It really is simple!
Do yourself a favor, make a test section. Rip up some longish staves
from any ol' board, make the birdsmouth cut, cut the staves into
eight equal lengths, say a foot or more long, and rubber band them
together. If you are still confused about taper, make youself a
little taper jig, as I described in a previous post, and trim all
your staves to it. Don't put in much taper, because you'l have to
bend the staves to make it. On a long mast the taper is so shallow
that the staves don't even notice it. On a short test section, it's
easy to go overboard.
All your questions will be answered.
John O'Neill
Birdsmouth is SIMPLE; talking about it is complicated. Check out the
birdsmouth folder I put in the files. I highly recomend doing the
taper after cuttting the birdsmouth. Running long, thin, tapering
staves through a tablesaw can be problematic, at best, dangerous at
worst, and cutting the taper is easy enough one (or several) at a
time for one mast, even after you've cut the birdsmouth.
After you've cut the birdsmouth, cut the taper from the width of the
stave (width of staves goes around the circumference of mast) on the
side opposite the birdsmouth. The staves all just end up bending in
slightly, making the taper. It really is simple!
Do yourself a favor, make a test section. Rip up some longish staves
from any ol' board, make the birdsmouth cut, cut the staves into
eight equal lengths, say a foot or more long, and rubber band them
together. If you are still confused about taper, make youself a
little taper jig, as I described in a previous post, and trim all
your staves to it. Don't put in much taper, because you'l have to
bend the staves to make it. On a long mast the taper is so shallow
that the staves don't even notice it. On a short test section, it's
easy to go overboard.
All your questions will be answered.
John O'Neill
--- In bolger@y..., porcupine@d... wrote:
> John,
>
> This sounds simple--basically what I've done constructing a four-
> sided blank for a round mast. But, uh, maybe I'm dense. Do you just
> plane the square edge of the staves, or do you plane both edges. If
> you plane both edges what do you do with the noblebirdsmouth, cut
it
> after tapering? If you cut it before tapering, how the hell does
the
> thing go together?
>
> Sigh! Maybe I should built a powerboat....
>
> porky
>
> --- In bolger@y..., jboatguy@c... wrote:
> > Taper is easy, and you can do it one at a time on the bench.
Some
> of
> > us like to figure ways of 'mass producing' taper so to speak, on
> the
> > tablesaw--or elsewhere.
> >
> > Taper with a handplane or even beltsander is easy with a guide.
I
> > used 1/8" ply nailed to the side of a long bench, and trimmed to
> > mimic my taper. Then I lined up 4 staves at a time next to it,
and
> > trimmed 'em down to the shape of the jig with a hand plane.
Takes
> no
> > time.
> >
> > John O'Neill.
> >
> > PS My two cents: birdsmouth is the only way to go. It is so
> cheap,
> > easy, and accurate, and you get such a strong, light spar as a
> > result, with no worries--ever--that a good breeze, aided by some
> left
> > over knots, will turn your cheap wood stick into a stump, that to
> me
> > there is simply no comparison to other methods.
John,
This sounds simple--basically what I've done constructing a four-
sided blank for a round mast. But, uh, maybe I'm dense. Do you just
plane the square edge of the staves, or do you plane both edges. If
you plane both edges what do you do with the noblebirdsmouth, cut it
after tapering? If you cut it before tapering, how the hell does the
thing go together?
Sigh! Maybe I should built a powerboat....
porky
This sounds simple--basically what I've done constructing a four-
sided blank for a round mast. But, uh, maybe I'm dense. Do you just
plane the square edge of the staves, or do you plane both edges. If
you plane both edges what do you do with the noblebirdsmouth, cut it
after tapering? If you cut it before tapering, how the hell does the
thing go together?
Sigh! Maybe I should built a powerboat....
porky
--- In bolger@y..., jboatguy@c... wrote:
> Taper is easy, and you can do it one at a time on the bench. Some
of
> us like to figure ways of 'mass producing' taper so to speak, on
the
> tablesaw--or elsewhere.
>
> Taper with a handplane or even beltsander is easy with a guide. I
> used 1/8" ply nailed to the side of a long bench, and trimmed to
> mimic my taper. Then I lined up 4 staves at a time next to it, and
> trimmed 'em down to the shape of the jig with a hand plane. Takes
no
> time.
>
> John O'Neill.
>
> PS My two cents: birdsmouth is the only way to go. It is so
cheap,
> easy, and accurate, and you get such a strong, light spar as a
> result, with no worries--ever--that a good breeze, aided by some
left
> over knots, will turn your cheap wood stick into a stump, that to
me
> there is simply no comparison to other methods.
Can I second the motion to post up a picture or diagram of this strip
tapering jig - I use a table saw a lot but your method just won't light up
for me!!
Foster Price
Derek wrote
tapering jig - I use a table saw a lot but your method just won't light up
for me!!
Foster Price
Derek wrote
> With a scrap wood strip-tapering jig (outlined
> below) the mast
> almost makes itself.
>
>
Taper is easy, and you can do it one at a time on the bench. Some of
us like to figure ways of 'mass producing' taper so to speak, on the
tablesaw--or elsewhere.
Taper with a handplane or even beltsander is easy with a guide. I
used 1/8" ply nailed to the side of a long bench, and trimmed to
mimic my taper. Then I lined up 4 staves at a time next to it, and
trimmed 'em down to the shape of the jig with a hand plane. Takes no
time.
John O'Neill.
PS My two cents: birdsmouth is the only way to go. It is so cheap,
easy, and accurate, and you get such a strong, light spar as a
result, with no worries--ever--that a good breeze, aided by some left
over knots, will turn your cheap wood stick into a stump, that to me
there is simply no comparison to other methods.
us like to figure ways of 'mass producing' taper so to speak, on the
tablesaw--or elsewhere.
Taper with a handplane or even beltsander is easy with a guide. I
used 1/8" ply nailed to the side of a long bench, and trimmed to
mimic my taper. Then I lined up 4 staves at a time next to it, and
trimmed 'em down to the shape of the jig with a hand plane. Takes no
time.
John O'Neill.
PS My two cents: birdsmouth is the only way to go. It is so cheap,
easy, and accurate, and you get such a strong, light spar as a
result, with no worries--ever--that a good breeze, aided by some left
over knots, will turn your cheap wood stick into a stump, that to me
there is simply no comparison to other methods.
--- In bolger@y..., porcupine@d... wrote:
> You know, all this niggling detail about tapering birds mouth masts
> is intimidating me. I thought that you could taper the mast by
> planing the square (non-birds mouth) side of each strip after
> cutting. This stuff all sounds very complicated. Would it be
simpler
> to build a nontapered birds mouth mast for the Micro and leave it
at
> that? Or am I missing something?
>
Yes, of course good local white pine would be OK! Lots and lots of
dories were built aout of it; why not a mast? For authoritative data
about relative properties of wood, you can download the "Wood
Handbook" aka The Bible at
http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr113/fplgtr113.htm
It will take a while at 56K though.
dories were built aout of it; why not a mast? For authoritative data
about relative properties of wood, you can download the "Wood
Handbook" aka The Bible at
http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr113/fplgtr113.htm
It will take a while at 56K though.
--- In bolger@y..., porcupine@d... wrote:
> Chris,
>
> To expand on my somewhat flip response to you that I posted
earlier,
> if I can use "spruce fir", whatever *that* is (and it is truely
> garbage wood, in my opinion), then could I not, for the same money,
> use essentially clear white pine from my local mill? I could treat
it
> in a similar way, or birdsmouth it. At least I would know what kind
> of wood I was using, and I would be supporting a local business,
and
> not some lumber McDonald's equivalent. I realize that white pine
> hasn't the strength of douglas fir or sitka spruce, and negligible
> rot resistance, but it is a joy to work with compared to
> lumberyard "spruce fir" or even lumberyard "pine". It is straight
> grained native white pine with a few scattered dime to quarter
sized
> knots. It costs less than US $4.00/bf,
>
> porky
>
>
> --- In bolger@y..., Chris Crandall <crandall@u...> wrote:
> > Even this can be turned into a decent mast. To do this, take the
> best
> > wood you can get. Rip it into 1/4 strips (or so). Laminate it
> with a
> > decent glue (epoxy or resorcinol are best for this). With epoxy
> decent
> > clamping is needed, with resorcinol, very good clamping is needed.
> >
> > This should take out the warp, and the glue lines will provide
> extra sheer
> > strength, and very little added weight. In your new "plywood"
> laminted
> > spar stock, proceed normally. It's a little extra work, but only
a
> couple
> > of hours. Of course, the smartest thing to do is to buy good
wood,
> but
> > sometimes it's cost-prohibitive, with shipping....
--- In bolger@y..., StepHydro@a... wrote:
diameter mast, tapering down to something else. The staves would be
1/2" x 1" at the foot of the mast with the 1" dimension tapering down
toward the top of the mast. To cut the staves, I would start with
some true 1" x 6" stock. I'd probably rip this in half to yeild two
1" x 3" pieces. I then cut the tapers so that I have two pieces of
stock which are 1" thick at one end tapering down to something less
at the other. I then set up the table saw to rip 1/2" strips fom the
stock, with the untapered surface of the stock placed down.
Hopefully, this will yield eight identical staves that are a uniform
1/2" thick but which taper from a 1" width to something less. I then
cut the birdsmouth on each stave. I use a dado blade on my table saw
turned 45 degrees.
Let's say that I have some 1" (true) x6" stock in an 8' length and a
5' length. If I scarf the lengths together (12:1 scarf) I'd end up
with a 12' 1x6 with the scarf nearer to one end than the other. It's
at this point that I would rip the stock yeilding two 1x3x12's. I
would then cut the taper on the two pices. One piece would have the
tapered end near to the scarf; the other piece would have the tapered
end far from the scarf. Then I'd rip the 1/2 thick staves from the
stock. When I glue the thing up, I alternate a stave with the scarf
near to the taper with a stave with the scarf far from the taper.
Regards
Andy Farquhar
> With pre-tapered stock, wouldn't the saw cut run out of theI'm not following you. Lets say that you are making a 2 1/2 inch
>material about halfway up the stave?
diameter mast, tapering down to something else. The staves would be
1/2" x 1" at the foot of the mast with the 1" dimension tapering down
toward the top of the mast. To cut the staves, I would start with
some true 1" x 6" stock. I'd probably rip this in half to yeild two
1" x 3" pieces. I then cut the tapers so that I have two pieces of
stock which are 1" thick at one end tapering down to something less
at the other. I then set up the table saw to rip 1/2" strips fom the
stock, with the untapered surface of the stock placed down.
Hopefully, this will yield eight identical staves that are a uniform
1/2" thick but which taper from a 1" width to something less. I then
cut the birdsmouth on each stave. I use a dado blade on my table saw
turned 45 degrees.
> >Let's stick with a 2 1/2" diameter mast and say it's to be 12' long.
> So, your mast needs to be 18 ft. long. You cut it into two (say)
>10' lengths and scarph. Now all the scarphs are at the same
>location. I missed something.
Let's say that I have some 1" (true) x6" stock in an 8' length and a
5' length. If I scarf the lengths together (12:1 scarf) I'd end up
with a 12' 1x6 with the scarf nearer to one end than the other. It's
at this point that I would rip the stock yeilding two 1x3x12's. I
would then cut the taper on the two pices. One piece would have the
tapered end near to the scarf; the other piece would have the tapered
end far from the scarf. Then I'd rip the 1/2 thick staves from the
stock. When I glue the thing up, I alternate a stave with the scarf
near to the taper with a stave with the scarf far from the taper.
Regards
Andy Farquhar
You know, all this niggling detail about tapering birds mouth masts
is intimidating me. I thought that you could taper the mast by
planing the square (non-birds mouth) side of each strip after
cutting. This stuff all sounds very complicated. Would it be simpler
to build a nontapered birds mouth mast for the Micro and leave it at
that? Or am I missing something?
porky
is intimidating me. I thought that you could taper the mast by
planing the square (non-birds mouth) side of each strip after
cutting. This stuff all sounds very complicated. Would it be simpler
to build a nontapered birds mouth mast for the Micro and leave it at
that? Or am I missing something?
porky
--- In bolger@y..., jboatguy@c... wrote:
> Derek,
>
> It sounds interesting, but I must be missing an important concept
in
> your strip carrier. could you be kind enough to go through it all
> again?
>
> I've thought of making a plywood jig with reverse taper, placing
the
> stave against it and bending it to match that taper, securing it
> somehow to the jig (tape?), and pushing it through to make the
curved
> cut with a straight blade. Is that the general idea? What do you
> mean 'ripping the whole thing to width'?
>
> Sorry, but I'm lost!!!
>
> John O'Neill
>
>
> --- In bolger@y..., "Derek Waters" <dgw@d...> wrote:
> >>
> > Strip jig:
> > One sub-standard strip (you did cut spares, eh?) is planed to the
> reverse of
> > the taper required. One good strip is laid along side the tapered
> piece (as
> > a spacer) and then another below-par piece is laid against the
> spacer to
> > form the outer retainer. Every couple of feet or so along the
> length of the
> > jig, plywood bridging plates are screwed to both of the jig
strips.
> Remove
> > the good (spacer) strip and pass the jig through the saw, ripping
> the whole
> > thing to width. You 've now made a strip carrier. Fix a wooden
stop
> block at
> > the 'push' end so that the strips dont slip. Set the saw blade to
> cut just
> > deeper than the depth of the strips and pass each good strip
> through the
> > saw. Fingerboards and fences keep everything calm. Either or both
> the jig
> > strips can be pieced together from shorter bits as the available
> stock
> > requires.
On Wed, 14 Feb 2001porcupine@...wrote:
is, will it bend (and not too far) and not break? I left my Wood Handbook
at home, so cannot look it up for you.
My guess is that it would be AOK if given the lamination treatment. But
not as clear wood--white pine isn't very strong. It is light, which makes
it good for drawer backs, etc.
Chris Crandallcrandall@...(785) 864-4131
Department of Psychology University of Kansas Lawrence, KS 66045
I have data convincingly disconfirming the Duhem-Quine hypothesis.
> Could I not, for the same money, use essentially clear white pine fromI think you could. The real question is the modulus of elasticity, that
> my local mill? I could treat it in a similar way, or birdsmouth it. At
> least I would know what kind of wood I was using, and I would be
> supporting a local business, and not some lumber McDonald's
> equivalent. I realize that white pine hasn't the strength of douglas
> fir or sitka spruce, and negligible rot resistance, but it is a joy to
> work with compared to lumberyard "spruce fir" or even lumberyard
> "pine". It is straight grained native white pine with a few scattered
> dime to quarter sized knots. It costs less than US $4.00/bf
is, will it bend (and not too far) and not break? I left my Wood Handbook
at home, so cannot look it up for you.
My guess is that it would be AOK if given the lamination treatment. But
not as clear wood--white pine isn't very strong. It is light, which makes
it good for drawer backs, etc.
Chris Crandallcrandall@...(785) 864-4131
Department of Psychology University of Kansas Lawrence, KS 66045
I have data convincingly disconfirming the Duhem-Quine hypothesis.
On Wed, 14 Feb 2001porcupine@...wrote:
the works of Mark Twain, wherein a few are discussed.
In addition, there are shantyboats, and some remarkable and handsome boats
for fishing the local rivers, including the Missouri, Kansas and Arkansas
Rivers. (Noteable point: Those last two rivers are pronounced so as to
rhyme.)
Local boatbuilding woods abound: black locust, walnut, osage orange, many
oaks, pines and cypress.
Still trying to find out more about sycamore, though.
> Thanks, Chris, I'm sure there's somebody out the reseaching the longThere are, of course, a host of native boats. You may be familiar with
> lost seafaring tradition of Kansas. You would have to go back to the
> Jurrasic, I believe <g>.
the works of Mark Twain, wherein a few are discussed.
In addition, there are shantyboats, and some remarkable and handsome boats
for fishing the local rivers, including the Missouri, Kansas and Arkansas
Rivers. (Noteable point: Those last two rivers are pronounced so as to
rhyme.)
Local boatbuilding woods abound: black locust, walnut, osage orange, many
oaks, pines and cypress.
Still trying to find out more about sycamore, though.
Chris,
To expand on my somewhat flip response to you that I posted earlier,
if I can use "spruce fir", whatever *that* is (and it is truely
garbage wood, in my opinion), then could I not, for the same money,
use essentially clear white pine from my local mill? I could treat it
in a similar way, or birdsmouth it. At least I would know what kind
of wood I was using, and I would be supporting a local business, and
not some lumber McDonald's equivalent. I realize that white pine
hasn't the strength of douglas fir or sitka spruce, and negligible
rot resistance, but it is a joy to work with compared to
lumberyard "spruce fir" or even lumberyard "pine". It is straight
grained native white pine with a few scattered dime to quarter sized
knots. It costs less than US $4.00/bf,
porky
To expand on my somewhat flip response to you that I posted earlier,
if I can use "spruce fir", whatever *that* is (and it is truely
garbage wood, in my opinion), then could I not, for the same money,
use essentially clear white pine from my local mill? I could treat it
in a similar way, or birdsmouth it. At least I would know what kind
of wood I was using, and I would be supporting a local business, and
not some lumber McDonald's equivalent. I realize that white pine
hasn't the strength of douglas fir or sitka spruce, and negligible
rot resistance, but it is a joy to work with compared to
lumberyard "spruce fir" or even lumberyard "pine". It is straight
grained native white pine with a few scattered dime to quarter sized
knots. It costs less than US $4.00/bf,
porky
--- In bolger@y..., Chris Crandall <crandall@u...> wrote:
> Even this can be turned into a decent mast. To do this, take the
best
> wood you can get. Rip it into 1/4 strips (or so). Laminate it
with a
> decent glue (epoxy or resorcinol are best for this). With epoxy
decent
> clamping is needed, with resorcinol, very good clamping is needed.
>
> This should take out the warp, and the glue lines will provide
extra sheer
> strength, and very little added weight. In your new "plywood"
laminted
> spar stock, proceed normally. It's a little extra work, but only a
couple
> of hours. Of course, the smartest thing to do is to buy good wood,
but
> sometimes it's cost-prohibitive, with shipping....
Derek,
It sounds interesting, but I must be missing an important concept in
your strip carrier. could you be kind enough to go through it all
again?
I've thought of making a plywood jig with reverse taper, placing the
stave against it and bending it to match that taper, securing it
somehow to the jig (tape?), and pushing it through to make the curved
cut with a straight blade. Is that the general idea? What do you
mean 'ripping the whole thing to width'?
Sorry, but I'm lost!!!
John O'Neill
It sounds interesting, but I must be missing an important concept in
your strip carrier. could you be kind enough to go through it all
again?
I've thought of making a plywood jig with reverse taper, placing the
stave against it and bending it to match that taper, securing it
somehow to the jig (tape?), and pushing it through to make the curved
cut with a straight blade. Is that the general idea? What do you
mean 'ripping the whole thing to width'?
Sorry, but I'm lost!!!
John O'Neill
--- In bolger@y..., "Derek Waters" <dgw@d...> wrote:
>>
> Strip jig:
> One sub-standard strip (you did cut spares, eh?) is planed to the
reverse of
> the taper required. One good strip is laid along side the tapered
piece (as
> a spacer) and then another below-par piece is laid against the
spacer to
> form the outer retainer. Every couple of feet or so along the
length of the
> jig, plywood bridging plates are screwed to both of the jig strips.
Remove
> the good (spacer) strip and pass the jig through the saw, ripping
the whole
> thing to width. You 've now made a strip carrier. Fix a wooden stop
block at
> the 'push' end so that the strips dont slip. Set the saw blade to
cut just
> deeper than the depth of the strips and pass each good strip
through the
> saw. Fingerboards and fences keep everything calm. Either or both
the jig
> strips can be pieced together from shorter bits as the available
stock
> requires.
Thanks, Chris, I'm sure there's somebody out the reseaching the long
lost seafaring tradition of Kansas. You would have to go back to the
Jurrasic, I believe <g>. Not too bad, when you consider that the last
time the Catskills were near an ocean was in the Devonian....
As for turning "spruce fir" into a mast, of course it can be done.
I've done it on smaller spars. It's an experience I would rather not
repeat. One could build a boat entirely of chicken wire and old
condoms, as well, but if there are better materials available, why
not use them?
porky
lost seafaring tradition of Kansas. You would have to go back to the
Jurrasic, I believe <g>. Not too bad, when you consider that the last
time the Catskills were near an ocean was in the Devonian....
As for turning "spruce fir" into a mast, of course it can be done.
I've done it on smaller spars. It's an experience I would rather not
repeat. One could build a boat entirely of chicken wire and old
condoms, as well, but if there are better materials available, why
not use them?
porky
--- In bolger@y..., Chris Crandall <crandall@u...> wrote:
> While it is not spar stock, black walnut is an excellent
boatbuilding
> wood, with beautiful grain, easy workability, and excellent rot
> resistance. In the olden days, Chesapeake Bay boats might use it
for
> transoms.
>
> Here's a trivia question: Which state provides the most walnut
lumber?
>
> The answer is on line 2 of my sig:
>
> Chris Crandall crandall@u... (785) 864-4131
> Department of Psychology University of Kansas Lawrence, KS
66045
> I have data convincingly disconfirming the Duhem-Quine hypothesis.
On Wed, 14 Feb 2001porcupine@...wrote:
wood you can get. Rip it into 1/4 strips (or so). Laminate it with a
decent glue (epoxy or resorcinol are best for this). With epoxy decent
clamping is needed, with resorcinol, very good clamping is needed.
This should take out the warp, and the glue lines will provide extra sheer
strength, and very little added weight. In your new "plywood" laminted
spar stock, proceed normally. It's a little extra work, but only a couple
of hours. Of course, the smartest thing to do is to buy good wood, but
sometimes it's cost-prohibitive, with shipping.
wood, with beautiful grain, easy workability, and excellent rot
resistance. In the olden days, Chesapeake Bay boats might use it for
transoms.
Here's a trivia question: Which state provides the most walnut lumber?
The answer is on line 2 of my sig:
Chris Crandallcrandall@...(785) 864-4131
Department of Psychology University of Kansas Lawrence, KS 66045
I have data convincingly disconfirming the Duhem-Quine hypothesis.
> I'm also sure that Bolger intended that the boat be built of justEven this can be turned into a decent mast. To do this, take the best
> about anyone's local sources. He's never been to the western
> Catskills, though. The lumberyards around here do not carry douglas
> fir lumber; They sell something called "spruce fir". It is pale,
> knotty, brittle, warped and weak.
wood you can get. Rip it into 1/4 strips (or so). Laminate it with a
decent glue (epoxy or resorcinol are best for this). With epoxy decent
clamping is needed, with resorcinol, very good clamping is needed.
This should take out the warp, and the glue lines will provide extra sheer
strength, and very little added weight. In your new "plywood" laminted
spar stock, proceed normally. It's a little extra work, but only a couple
of hours. Of course, the smartest thing to do is to buy good wood, but
sometimes it's cost-prohibitive, with shipping.
> Hell, I can get clear black walnut from this mill for nearly what IWhile it is not spar stock, black walnut is an excellent boatbuilding
> would pay for some warped "spruce fir" from Home Depot. I don't think
> black walnut would make a good mast, though. It's heavy heavy stuff.
wood, with beautiful grain, easy workability, and excellent rot
resistance. In the olden days, Chesapeake Bay boats might use it for
transoms.
Here's a trivia question: Which state provides the most walnut lumber?
The answer is on line 2 of my sig:
Chris Crandallcrandall@...(785) 864-4131
Department of Psychology University of Kansas Lawrence, KS 66045
I have data convincingly disconfirming the Duhem-Quine hypothesis.
Peter,
I'm also sure that Bolger intended that the boat be built of just
about anyone's local sources. He's never been to the western
Catskills, though. The lumberyards around here do not carry douglas
fir lumber; They sell something called "spruce fir". It is pale,
knotty, brittle, warped and weak. They also sell 1/2" pine plywood,
sometimes 3/8", usually warped. You can get AC exterior fir plywood
for about US $30.00 per 1/2" sheet, but if you try to buy *any*
structural plywood, they'll try to talk you into that chipboard
stuff. Don't even try to ask about "marine" plywood. They'll tell you
that boats are all made of fiberglass now. The only available 1/4"
ply is luan underlayment of declining quality and questionable glue.
There is a lumbermill here that cuts local wood. They sell select
white pine and eastern cedar for less than the garbage the yards
sell. Hell, I can get clear black walnut from this mill for nearly
what I would pay for some warped "spruce fir" from Home Depot. I
don't think black walnut would make a good mast, though. It's heavy
heavy stuff.
Anyway, the point is that the "home improvement" outfits here market
to the lowest common denominator. I suppose that, given the relative
poverty of the area, there is little market for higher quality
supplies. Therefore my posted options,
Thanks,
porky
I'm also sure that Bolger intended that the boat be built of just
about anyone's local sources. He's never been to the western
Catskills, though. The lumberyards around here do not carry douglas
fir lumber; They sell something called "spruce fir". It is pale,
knotty, brittle, warped and weak. They also sell 1/2" pine plywood,
sometimes 3/8", usually warped. You can get AC exterior fir plywood
for about US $30.00 per 1/2" sheet, but if you try to buy *any*
structural plywood, they'll try to talk you into that chipboard
stuff. Don't even try to ask about "marine" plywood. They'll tell you
that boats are all made of fiberglass now. The only available 1/4"
ply is luan underlayment of declining quality and questionable glue.
There is a lumbermill here that cuts local wood. They sell select
white pine and eastern cedar for less than the garbage the yards
sell. Hell, I can get clear black walnut from this mill for nearly
what I would pay for some warped "spruce fir" from Home Depot. I
don't think black walnut would make a good mast, though. It's heavy
heavy stuff.
Anyway, the point is that the "home improvement" outfits here market
to the lowest common denominator. I suppose that, given the relative
poverty of the area, there is little market for higher quality
supplies. Therefore my posted options,
Thanks,
porky
--- In bolger@y..., pvanderw@o... wrote:
> > What techniques have been used (successfully or
> > not) to build the main mast, and in what materials?
>
> The option that I do not see in your list is Douglas Fir from Home
> Depot or the local lumberyard. I'm pretty sure that PCB wanted it
to
> be possible to build the boat using just about anyone's local
sources.
>
> PHV
Andy,
Would you mind having another go at the below. I am certain that the
information is in there, but I can't retreive it.
In a message dated 02/14/2001 10:<BR26:<BR33 AM
Eastern Standard,pongo19050@...writes:
halfway up the stave?
and scarph. Now all the scarphs are at the same location. I missed something
;-)
Cheers/Carron
Would you mind having another go at the below. I am certain that the
information is in there, but I can't retreive it.
In a message dated 02/14/2001 10:<BR26:<BR33 AM
Eastern Standard,pongo19050@...writes:
> When building a tapered birdsmouth mast, I have found that it isWith pre-tapered stock, wouldn't the saw cut run out of the material about
> easier to taper the stock from which you rip the staves. This way,
> you only have to cut one or two tapers, instead of eight, and all of
> the tapers are identical.
halfway up the stave?
>So, your mast needs to be 18 ft. long. You cut it into two (say) 10' lengths
> If I am scarfing the stock, I cut it in half and then run the tapers
> from opposite directions so that the scarfs in the staves do not line
> up in the finished mast. This is probably the result of paranoia
> because a 12/1 scarf is probably stronger and stiffer that the rest
> of the stave.
and scarph. Now all the scarphs are at the same location. I missed something
;-)
Cheers/Carron
When building a tapered birdsmouth mast, I have found that it is
easier to taper the stock from which you rip the staves. This way,
you only have to cut one or two tapers, instead of eight, and all of
the tapers are identical.
If I am scarfing the stock, I cut it in half and then run the tapers
from opposite directions so that the scarfs in the staves do not line
up in the finished mast. This is probably the result of paranoia
because a 12/1 scarf is probably stronger and stiffer that the rest
of the stave.
That said, for my Oldshoe, which is a micro Micro, I just built the
masts from the clearest 2x4s that I could find at Home Depot,
laminated together according to the plans. In the end, I would have
saved time if I built them hollow because it took so long to taper
them using a plane then belt sander.
Regards
Andy Farquhar
easier to taper the stock from which you rip the staves. This way,
you only have to cut one or two tapers, instead of eight, and all of
the tapers are identical.
If I am scarfing the stock, I cut it in half and then run the tapers
from opposite directions so that the scarfs in the staves do not line
up in the finished mast. This is probably the result of paranoia
because a 12/1 scarf is probably stronger and stiffer that the rest
of the stave.
That said, for my Oldshoe, which is a micro Micro, I just built the
masts from the clearest 2x4s that I could find at Home Depot,
laminated together according to the plans. In the end, I would have
saved time if I built them hollow because it took so long to taper
them using a plane then belt sander.
Regards
Andy Farquhar
Hollow masts come within a few percentage points as strong as their
solid cousins because the inner wood adds little to strength and lots
to weight. A birdsmouth mast will come out stronger then Bolger
intended becasue he doesn't expect his Micro builders to use high
quality wood in their spars, and takes that into account. If you're
still concerned, increase the diameter by 10%. Your mast will be
PLENTY strong, unstayed or not. If you go for a round mast, increase
the diameter by 1.03 over Bolgers octoganal spec, to get the same
cross-sectional area.
John O'Neill
solid cousins because the inner wood adds little to strength and lots
to weight. A birdsmouth mast will come out stronger then Bolger
intended becasue he doesn't expect his Micro builders to use high
quality wood in their spars, and takes that into account. If you're
still concerned, increase the diameter by 10%. Your mast will be
PLENTY strong, unstayed or not. If you go for a round mast, increase
the diameter by 1.03 over Bolgers octoganal spec, to get the same
cross-sectional area.
John O'Neill
--- In bolger@y..., porcupine@d... wrote:
>
>
> Okay. There have been rumors of spring actually coming to the
> Catskills, and I'm considering finally getting serious about these
> Micro plans I own.
>
> What techniques have been used (successfully or
> not) to build the main mast, and in what materials? I can get
either
> sitka spruce or (real) douglas fir from M.L.Condon down in
> Mountainville (100 miles from here) or eastern white pine or
eastern
> white cedar from a local mill (20 miles). I realize that the spruce
> would be best, but at about US $8.00/bf it would run me close to US
> $400 for just that one spar. All the other choices cost less than
> half that.
> What techniques have been used (successfully orThe option that I do not see in your list is Douglas Fir from Home
> not) to build the main mast, and in what materials?
Depot or the local lumberyard. I'm pretty sure that PCB wanted it to
be possible to build the boat using just about anyone's local sources.
PHV
Two cents worth...
If you have access to even the most basic tablesaw, birdsmouth need not be
complex. With a scrap wood strip-tapering jig (outlined below) the mast
almost makes itself.
Birdsmouth allows you an easy way to make long spars from short stock,
spreading scarfs around. The birdsmouth strips are small enough to be easy
to scarf, with another scrap wood jig. It would be possible to use the
birdsmouth method and still to approximate Mr Bolger's scantlings. Jim
Michalak has an interesting page on hollow mast design, and gives the
necessary math for deciding just how hollow you want to make your mast...
BS6566 is nominally second best to BS1088 (see
http://www.marineply.com/technical.htmfor an outline of the standard)
but seems often as good as the higher grade - the stuff I've had has been
great.
Cheers
Derek
Strip jig:
One sub-standard strip (you did cut spares, eh?) is planed to the reverse of
the taper required. One good strip is laid along side the tapered piece (as
a spacer) and then another below-par piece is laid against the spacer to
form the outer retainer. Every couple of feet or so along the length of the
jig, plywood bridging plates are screwed to both of the jig strips. Remove
the good (spacer) strip and pass the jig through the saw, ripping the whole
thing to width. You 've now made a strip carrier. Fix a wooden stop block at
the 'push' end so that the strips dont slip. Set the saw blade to cut just
deeper than the depth of the strips and pass each good strip through the
saw. Fingerboards and fences keep everything calm. Either or both the jig
strips can be pieced together from shorter bits as the available stock
requires.
If you have access to even the most basic tablesaw, birdsmouth need not be
complex. With a scrap wood strip-tapering jig (outlined below) the mast
almost makes itself.
Birdsmouth allows you an easy way to make long spars from short stock,
spreading scarfs around. The birdsmouth strips are small enough to be easy
to scarf, with another scrap wood jig. It would be possible to use the
birdsmouth method and still to approximate Mr Bolger's scantlings. Jim
Michalak has an interesting page on hollow mast design, and gives the
necessary math for deciding just how hollow you want to make your mast...
BS6566 is nominally second best to BS1088 (see
http://www.marineply.com/technical.htmfor an outline of the standard)
but seems often as good as the higher grade - the stuff I've had has been
great.
Cheers
Derek
Strip jig:
One sub-standard strip (you did cut spares, eh?) is planed to the reverse of
the taper required. One good strip is laid along side the tapered piece (as
a spacer) and then another below-par piece is laid against the spacer to
form the outer retainer. Every couple of feet or so along the length of the
jig, plywood bridging plates are screwed to both of the jig strips. Remove
the good (spacer) strip and pass the jig through the saw, ripping the whole
thing to width. You 've now made a strip carrier. Fix a wooden stop block at
the 'push' end so that the strips dont slip. Set the saw blade to cut just
deeper than the depth of the strips and pass each good strip through the
saw. Fingerboards and fences keep everything calm. Either or both the jig
strips can be pieced together from shorter bits as the available stock
requires.
Okay. There have been rumors of spring actually coming to the
Catskills, and I'm considering finally getting serious about these
Micro plans I own.
What techniques have been used (successfully or
not) to build the main mast, and in what materials? I can get either
sitka spruce or (real) douglas fir from M.L.Condon down in
Mountainville (100 miles from here) or eastern white pine or eastern
white cedar from a local mill (20 miles). I realize that the spruce
would be best, but at about US $8.00/bf it would run me close to US
$400 for just that one spar. All the other choices cost less than
half that. I could save some money at considerably increased
complexity by building the main mast using birds mouths, but I'm
hesitant to use the technique on an unstayed mast. Any thoughts?
Also, M.L.Condon has douglas fir or rotary sliced philipine mahogany
marine plywood. 1/4" fir costs $40.00 and 1/4" mahogany costs $28.80.
Noah's, out near Buffalo and about 250 miles from me, has "B/BB
Okoume (gabon) #BS6566, Lloyds Approval #91/00457", 6mm for $38.00
with a 5% discount for orders of more than 10 sheets. Any opinions on
what I should go with? Does anyone know what all those numbers
attached to the Okoume plywood mean?
TIA,
porky
Catskills, and I'm considering finally getting serious about these
Micro plans I own.
What techniques have been used (successfully or
not) to build the main mast, and in what materials? I can get either
sitka spruce or (real) douglas fir from M.L.Condon down in
Mountainville (100 miles from here) or eastern white pine or eastern
white cedar from a local mill (20 miles). I realize that the spruce
would be best, but at about US $8.00/bf it would run me close to US
$400 for just that one spar. All the other choices cost less than
half that. I could save some money at considerably increased
complexity by building the main mast using birds mouths, but I'm
hesitant to use the technique on an unstayed mast. Any thoughts?
Also, M.L.Condon has douglas fir or rotary sliced philipine mahogany
marine plywood. 1/4" fir costs $40.00 and 1/4" mahogany costs $28.80.
Noah's, out near Buffalo and about 250 miles from me, has "B/BB
Okoume (gabon) #BS6566, Lloyds Approval #91/00457", 6mm for $38.00
with a 5% discount for orders of more than 10 sheets. Any opinions on
what I should go with? Does anyone know what all those numbers
attached to the Okoume plywood mean?
TIA,
porky