Re: aluminum mast

You can get thin wall aluminum pipe which makes an excellent mast. If
you nest (double up or even triple) material in the stressed areas, you
can go without stays. Schedule 40 weighs a ton and will be to too
flexible to use without stays.

Sources for thin wall in larger sizes is Aircraft Spruce and LEAF,
Leading Edge Airfoils. Both supply for ultralight aircraft. I have
unstayed 16' spars from an ultralight we use on landsailers that are
indestructable and very light. Outer tube is 2", smaller stuff nested
inside. Do a short, 1 foot triple nesting at the deck if avoiding
stays.

You can also use nesting and a few pop rivets to create a mast you can
break down into sections.

A very good solution.

Dave G.

--- Inbolger@yahoogroups.com, "goldenretriever222000"
<molly.sullivan@c...> wrote:

> Hi,
>
> Does anyone know if you need to use stays for an aluminum mast on a
> boat like Junebug. My father and I built Junebug last year and we had
> trouble with the mast, so we decided to try an aluminum mast this
> year. We bought Schedule 40 aluminum tubing. The alloy is 6061-T6.
> Does anyone have any advice about aluminum masts? Any help would be
> greatly appreciated! Thanks.
>
> Molly

I use all manner of t6 alloysin my landyacht building. What is the
diameter and wall thickness?. I can then tel you what Icould do with
iton a landyacht . ths will give you a good comparson as I also hve a
JUne Bug.
Cheers Paul.
Boataholics anoymous will never claim me. thefleet is currently at 6
landyachts and 4 boats. 3 landyachts under construction!

--- Inbolger@yahoogroups.com, craig o'donnell <dadadata@f...> wrote:

> Hi,
>
> Does anyone know if you need to use stays for an aluminum mast on a
> boat like Junebug. My father and I built Junebug last year and we had
> trouble with the mast, so we decided to try an aluminum mast this
> year. We bought Schedule 40 aluminum tubing. The alloy is 6061-T6.
> Does anyone have any advice about aluminum masts? Any help would be
> greatly appreciated! Thanks.
>
> Molly
>
> How big is the mast? (Height ... diameter) You shouldn't need stays

but a

> 1.5-inch one-piece mast can only take a fairly small sail without

excessive

> bending. Then again, a sprit-boomed sail isn't really meant to be on

stayed

> masts.
>
> An old canoe sailor's trick is to run the halyard to a block on the bow,
> and then bring it back to the cockpit, creating a "forestay" if you

will.

> --
> Craig O'Donnell
> Sinepuxent Ancestors & Boats
> <http://freepages.genealogy.rootsweb.com/~fassitt/>
> The Proa FAQ <http://boat-links.com/proafaq.html>
> The Cheap Pages <http://www.friend.ly.net/~dadadata/>
> Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
> American Proas, the Bolger Boat Honor Roll,
> Plywood Boats, Bamboo Rafts, &c.
> _________________________________
>
> -- Professor of Boatology -- Junkomologist
> -- Macintosh kinda guy
> Friend of Wanda the Wonder Cat, 1991-1997.
> _________________________________
>
> [Non-text portions of this message have been removed]

Thanks for the help! We have two options for the sail. Last year, I
made a tarp sail from Junebug's plans. The total mast length for that
sail is 15'8''. However, my grandfather gave us a really nice sail
this year from his old sailboat, but the sail is larger. It would need
about an 18' mast, unless I tried to alter the sail itself.

Thanks again

Molly

Hi,

Does anyone know if you need to use stays for an aluminum mast on a
boat like Junebug. My father and I built Junebug last year and we had
trouble with the mast, so we decided to try an aluminum mast this
year. We bought Schedule 40 aluminum tubing. The alloy is 6061-T6.
Does anyone have any advice about aluminum masts? Any help would be
greatly appreciated! Thanks.

Molly

How big is the mast? (Height ... diameter) You shouldn't need stays but a
1.5-inch one-piece mast can only take a fairly small sail without excessive
bending. Then again, a sprit-boomed sail isn't really meant to be on stayed
masts.

An old canoe sailor's trick is to run the halyard to a block on the bow,
and then bring it back to the cockpit, creating a "forestay" if you will.
--
Craig O'Donnell
Sinepuxent Ancestors & Boats
<http://freepages.genealogy.rootsweb.com/~fassitt/>
The Proa FAQ <http://boat-links.com/proafaq.html>
The Cheap Pages <http://www.friend.ly.net/~dadadata/>
Sailing Canoes, Polytarp Sails, Bamboo, Chinese Junks,
American Proas, the Bolger Boat Honor Roll,
Plywood Boats, Bamboo Rafts, &c.
_________________________________

-- Professor of Boatology -- Junkomologist
-- Macintosh kinda guy
Friend of Wanda the Wonder Cat, 1991-1997.
_________________________________

[Non-text portions of this message have been removed]

--- Inbolger@yahoogroups.com, "goldenretriever222000"
<molly.sullivan@c...> wrote:

> Hi,
>
> Does anyone know if you need to use stays for an aluminum mast on a
> boat like Junebug. My father and I built Junebug last year and we

had

> trouble with the mast, so we decided to try an aluminum mast this
> year. We bought Schedule 40 aluminum tubing. The alloy is 6061-T6.
> Does anyone have any advice about aluminum masts? Any help would be
> greatly appreciated! Thanks.
>
> Molly

Depends on the stress. I went to an aluminum mast (unstayed) on the
19.5 foot v-bottom catboat I built a few years ago and followed a
specification that Bolger provided. There were no problems and that
gaff sail was 135 square feet, considerably larger than June Bug's 59
square feet. I think it was a schedule 40 pipe, although it is 3.5
inches in diameter. I don't remember the type, it may have been 6061.
The shop where you bought it should know whether weathering/corrosion
will be a problem. My guess is if the walls of your pipe are 1/16-
inch or thicker, it's plenty strong enough. (The walls are about 1/8-
inch on mine.)

You could always put each end of the pipe on a sawhorse, with the
middle unsupported. Then lean on it, gradually applying more
pressure. If it takes most of your weight (and you're a normal size
person), it would be plenty strong enough. If in use it gets that
much strain, you'll probably get flipped . . .

Which brings up this point:You might want to seal the top of the mast
with foam so if/when you tip over, the air in the mast provides some
bouyancy and maybe keeps the boat from turning turtle. . .

Gary Blankenship