On Mon, 5 Dec 2005 16:18:40 -0600, "Art Ransom"
wrote:

I have heard that bead and cove joints can be used for mast/spar building.
Anyone ever done this?


A similar, less labor intensive method is providing strips with one
fish mouth edge - 45 degrees, 90 degrees, 45 degrees.
The fish mouth fits the inner edge of the next strip.
All held together with hose clamps or tourniquets during glueing.
There is an optimal width/thickness for a mast diameter.
Search the web

Brian Whatcott Altus OK

That's the "Noble System" which was written up as "Bird's Mouth Hollow
Spars" by Aimé Ontario Fraser in Wooden Boat Magazine, July/August 1999

I've an expurgated version of the Wooden Boat article, with photos, that I
prepared if you'd like it. (Aimé spent too may words on social/dining
issues for my taste.) It's a huge file, 16 MBy, and of course it's
copyrighted material.

The scantlings given were, for an 8-sided spar:
Stave width: 0.4 x diameter of spar - taper square edge
Stave thickness: between 0.1 and 0.2 x spar diameter - (bigger for big
boats) (0.2 for spruce, 0.15 for Douglas Fir)

I think the scheme is also discussed near the back of Hassler/McCloud's
"Practical Junk Rig."

Roger

http://home.insightbb.com/~derbyrm

"Brian Whatcott" wrote in message
...
On Mon, 5 Dec 2005 16:18:40 -0600, "Art Ransom"
wrote:

I have heard that bead and cove joints can be used for mast/spar building.
Anyone ever done this?


A similar, less labor intensive method is providing strips with one
fish mouth edge - 45 degrees, 90 degrees, 45 degrees.
The fish mouth fits the inner edge of the next strip.
All held together with hose clamps or tourniquets during glueing.
There is an optimal width/thickness for a mast diameter.
Search the web

Brian Whatcott Altus OK

http://www.woodline.com/scripts/instructions.asp gives instructions on
how to do
this for varying numbers of strakes using their router bits.

Frank

"derbyrm" wrote in message
news:kcglf.624312$xm3.226764@attbi_s21...
That's the "Noble System" which was written up as "Bird's Mouth Hollow
Spars" by Aimé Ontario Fraser in Wooden Boat Magazine, July/August 1999

I've an expurgated version of the Wooden Boat article, with photos, that I
prepared if you'd like it. (Aimé spent too may words on social/dining
issues for my taste.) It's a huge file, 16 MBy, and of course it's
copyrighted material.

The scantlings given were, for an 8-sided spar:
Stave width: 0.4 x diameter of spar - taper square edge
Stave thickness: between 0.1 and 0.2 x spar diameter - (bigger for big
boats) (0.2 for spruce, 0.15 for Douglas Fir)

I found a few programs to calculate the dimensions. Although windows
applications, they're only 60kB large. I can mail them to anyone who's
interested.

Meindert