Re: [bolger] Re: broken hollow mast
On an unstayed, hollow mast, the partner will crush the mast out of round
if they can, as has been stated. In the Freedom, there's no plug, but the
partner is special - a carefully-formed urethane rubber plug to distribute
the load.
But, why not wrap 10 layers, 1/4" thick?, 3 inch glass tape around the mast
at the deck (if you can't or didn't plug it)?
GHC
At 04:42 PM 2/15/2001 -0000, you wrote:
if they can, as has been stated. In the Freedom, there's no plug, but the
partner is special - a carefully-formed urethane rubber plug to distribute
the load.
But, why not wrap 10 layers, 1/4" thick?, 3 inch glass tape around the mast
at the deck (if you can't or didn't plug it)?
GHC
At 04:42 PM 2/15/2001 -0000, you wrote:
>--- In bolger@y..., "Larry Barker" <lgbarker@i...> wrote:
>> Andy,
>> Did you use the glass in addition to or instead of a plug at the
>partner?
>> Thanks,
>> Larry Barker
>
>Just the glass. Since it was a yard before it was a mast, it was
>only plugged three inches or so from each end.
>
>I have also thought of laying up a spar using carbon fiber tape set
>in epoxy on the inside surface of each stave where it would not be
>seen, but the stuff is so expensive.
>
>Regards
>
>Andy Farquhar
>
>
>
>Bolger rules!!!
>- no cursing, flaming, trolling, or spamming
>- no flogging dead horses
>- add something: take "thanks!" and "ditto!" posts off-list.
>- stay on topic and punctuate
>- add your comments at the TOP and SIGN your posts
>
>
>
--- In bolger@y..., "Larry Barker" <lgbarker@i...> wrote:
only plugged three inches or so from each end.
I have also thought of laying up a spar using carbon fiber tape set
in epoxy on the inside surface of each stave where it would not be
seen, but the stuff is so expensive.
Regards
Andy Farquhar
> Andy,partner?
> Did you use the glass in addition to or instead of a plug at the
> Thanks,Just the glass. Since it was a yard before it was a mast, it was
> Larry Barker
only plugged three inches or so from each end.
I have also thought of laying up a spar using carbon fiber tape set
in epoxy on the inside surface of each stave where it would not be
seen, but the stuff is so expensive.
Regards
Andy Farquhar
Andy,
Did you use the glass in addition to or instead of a plug at the partner?
Thanks,
Larry Barker
Did you use the glass in addition to or instead of a plug at the partner?
Thanks,
Larry Barker
----- Original Message -----
From: <pongo19050@...>
To: <bolger@yahoogroups.com>
Sent: Thursday, February 15, 2001 7:13 AM
Subject: [bolger] Re: broken hollow mast
> I recently made a birdsmouth yard into a mast. I was paranoid about
> its ability to hold up at the mast partner and elsewhere and so
> wrapped in in two layers of 6 oz. glass tape set in epoxy. This did
> not make the spar appreciably stiffer, but it's pretty bullet proof.
> I filled in the weave with epoxy so that it still looks like wood.
>
> You could taper the glass from 2 layers at the partner to 1 layer and
> then no glass covering above. This may spread out the stresses
> inherent in a solid plug.
>
<snip>
I recently made a birdsmouth yard into a mast. I was paranoid about
its ability to hold up at the mast partner and elsewhere and so
wrapped in in two layers of 6 oz. glass tape set in epoxy. This did
not make the spar appreciably stiffer, but it's pretty bullet proof.
I filled in the weave with epoxy so that it still looks like wood.
You could taper the glass from 2 layers at the partner to 1 layer and
then no glass covering above. This may spread out the stresses
inherent in a solid plug.
I use hardwood plugs at the mast head so that I can drill out a
dumbsheave.
Regards
Andy Farquhar
its ability to hold up at the mast partner and elsewhere and so
wrapped in in two layers of 6 oz. glass tape set in epoxy. This did
not make the spar appreciably stiffer, but it's pretty bullet proof.
I filled in the weave with epoxy so that it still looks like wood.
You could taper the glass from 2 layers at the partner to 1 layer and
then no glass covering above. This may spread out the stresses
inherent in a solid plug.
I use hardwood plugs at the mast head so that I can drill out a
dumbsheave.
Regards
Andy Farquhar
fraser.howell@...wrote:
partner (ie it is only hollow above the partner) to prevent flex at
this point of maximum strain.
On the subject of Birdsmouth/Noble spars, there was an excellent
article in WoodenBoat, I think early last year, which documented
this technique in great detail, with lots of pictures. The guys
who demonstrated the technique run a small boatshop in the US and
I suspect that they either developed the technique independently
of Noble, or the technique has been passed on over the years and
the original source has been forgotten. The next WoodenBoat edition
had some mention of Noble and the patent.
Bruce Fountain.
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> I built a birdsmouth mast for my chebacco last winter. This is anIt is probably a good idea to plug your hollow mast to just above the
> unstayed stick, nineteen feet long, four inches in diameter. I adhered
> to the recommended scantlings to the millimeter. Epoxy glued,
> perfectly
> clear Nova Scotia red spruce. It lasted 6 weeks. Snapped off at the
> partner in relatively light winds. No glue failure.
> But it was neat, I'm building another.
partner (ie it is only hollow above the partner) to prevent flex at
this point of maximum strain.
On the subject of Birdsmouth/Noble spars, there was an excellent
article in WoodenBoat, I think early last year, which documented
this technique in great detail, with lots of pictures. The guys
who demonstrated the technique run a small boatshop in the US and
I suspect that they either developed the technique independently
of Noble, or the technique has been passed on over the years and
the original source has been forgotten. The next WoodenBoat edition
had some mention of Noble and the patent.
Bruce Fountain.
**********************************************************************
This email and any files transmitted with it from Mi Services
Group may contain information which is
privileged, confidential and protected from disclosure.
If it is not addressed to you, please immediately contact
nzpostmaster@...and do not use, disclose,
copy, distribute or retain any of it without our authority.
**********************************************************************
I built a birdsmouth mast for my chebacco last winter. This is an
unstayed stick, nineteen feet long, four inches in diameter. I adhered
to the recommended scantlings to the millimeter. Epoxy glued, perfectly
clear Nova Scotia red spruce. It lasted 6 weeks. Snapped off at the
partner in relatively light winds. No glue failure.
But it was neat, I'm building another.
Good luck, keep a solid backup
Fraser Howell
unstayed stick, nineteen feet long, four inches in diameter. I adhered
to the recommended scantlings to the millimeter. Epoxy glued, perfectly
clear Nova Scotia red spruce. It lasted 6 weeks. Snapped off at the
partner in relatively light winds. No glue failure.
But it was neat, I'm building another.
Good luck, keep a solid backup
Fraser Howell