Re: Mast Shaping Questions
To layout the line for an ocatagon, imagine you have a square spar
that is 1". You need to lay lines in from all four corners on all
four sides .31" (or .31 x 2.5" in your case). This leaves an octagon
flat of .38.
For a tapered mast make a block say 4" wide, drive a pair of nails
with 3" between them, add a nail .93" inside of each of these. Drive
the two middle nails so they are coming through from the off side,
and are short. if the outer nails are skewed to ride on the sides of
your spar, the inner nails will scratch proportional layout lines for
you. You could also use pencils. If you have a drawknife and planes
use them.
I would probably just eyeball the remaining flats when I had the
octagon.
that is 1". You need to lay lines in from all four corners on all
four sides .31" (or .31 x 2.5" in your case). This leaves an octagon
flat of .38.
For a tapered mast make a block say 4" wide, drive a pair of nails
with 3" between them, add a nail .93" inside of each of these. Drive
the two middle nails so they are coming through from the off side,
and are short. if the outer nails are skewed to ride on the sides of
your spar, the inner nails will scratch proportional layout lines for
you. You could also use pencils. If you have a drawknife and planes
use them.
I would probably just eyeball the remaining flats when I had the
octagon.
--- In bolger@y..., "pseudodion42" <pseudodion3@a...> wrote:
> Hi, folks. I need a quick lesson in mast shaping. The Dobler plans
I
> am working from call for a mast 13'4" long. It should be 2 1/2"
> square from the heel to gooseneck (38")-- no problem. It will be 2
> 1/2" round from the gooseneck for 44" at which point it tapers to 1
> 1/4" all the way to the top of the mast.
>
> I glued up some practice pieces and started making sawdust, but
> things don't look right and so I have a few questions:
>
> 1. How deep does the saw blade need to bite into the cut? I noticed
> that I have some large flat places in my octagonal shape.
>
> 2. Does one draw lines to be cut on all four sides of the stock, or
> just the fore and aft faces?
>
> 3. Isn't there an easier way to do this? Sheesh!
>
> Thanks for the replies,
>
> Dennis
Hi Dennis, This is not really a difficult process. What you are doing
is 8 siding, 16 siding and 32 siding to get to round. Except for the
taper ( is it a true taper or does it have "entasis"?) you don't use a
saw. A sharp plane is what you want. You also want "Woodenboat #125
and Bud Mackintosh's article on sparmaking. This can't be answered in
words but needs pictures. I'm going to Saginaw tomorrow for the "Great
Lakes Small Boat Symposium" or whatever they call it so can't mail
anything to you tomorrow but will get back to you.
Bob Chamberland
is 8 siding, 16 siding and 32 siding to get to round. Except for the
taper ( is it a true taper or does it have "entasis"?) you don't use a
saw. A sharp plane is what you want. You also want "Woodenboat #125
and Bud Mackintosh's article on sparmaking. This can't be answered in
words but needs pictures. I'm going to Saginaw tomorrow for the "Great
Lakes Small Boat Symposium" or whatever they call it so can't mail
anything to you tomorrow but will get back to you.
Bob Chamberland
--- In bolger@y..., "pseudodion42" <pseudodion3@a...> wrote:
> Hi, folks. I need a quick lesson in mast shaping. The Dobler plans I
> am working from call for a mast 13'4" long. It should be 2 1/2"
> square from the heel to gooseneck (38")-- no problem. It will be 2
> 1/2" round from the gooseneck for 44" at which point it tapers to 1
> 1/4" all the way to the top of the mast.
>
> I glued up some practice pieces and started making sawdust, but
> things don't look right and so I have a few questions:
>
> 1. How deep does the saw blade need to bite into the cut? I noticed
> that I have some large flat places in my octagonal shape.
>
> 2. Does one draw lines to be cut on all four sides of the stock, or
> just the fore and aft faces?
>
> 3. Isn't there an easier way to do this? Sheesh!
>
> Thanks for the replies,
>
> Dennis
Hi, folks. I need a quick lesson in mast shaping. The Dobler plans I
am working from call for a mast 13'4" long. It should be 2 1/2"
square from the heel to gooseneck (38")-- no problem. It will be 2
1/2" round from the gooseneck for 44" at which point it tapers to 1
1/4" all the way to the top of the mast.
I glued up some practice pieces and started making sawdust, but
things don't look right and so I have a few questions:
1. How deep does the saw blade need to bite into the cut? I noticed
that I have some large flat places in my octagonal shape.
2. Does one draw lines to be cut on all four sides of the stock, or
just the fore and aft faces?
3. Isn't there an easier way to do this? Sheesh!
Thanks for the replies,
Dennis
am working from call for a mast 13'4" long. It should be 2 1/2"
square from the heel to gooseneck (38")-- no problem. It will be 2
1/2" round from the gooseneck for 44" at which point it tapers to 1
1/4" all the way to the top of the mast.
I glued up some practice pieces and started making sawdust, but
things don't look right and so I have a few questions:
1. How deep does the saw blade need to bite into the cut? I noticed
that I have some large flat places in my octagonal shape.
2. Does one draw lines to be cut on all four sides of the stock, or
just the fore and aft faces?
3. Isn't there an easier way to do this? Sheesh!
Thanks for the replies,
Dennis