stainless steel mast?

[Buc]

Yes, you can certainly build a wood box mast. It's how masts were built for years. The box will be stronger than a solid mast of the same dimensions and, obviously, mugh lighter. Fiberglassing isn't really necessary, though it would reduce maintenance somewhat. It would also increase the weight. As the glass is primarily for protection, use as few layers as possible; one would be fine.

As for titanium masts on racing boats, I made reference earlier to Weatherly's mast with the upper third made of Ti. Its use was outlawed by the IOR for cost reasons, but Weatherly's mast was grandfathered when she went from being an America's Cup 12-meter to racing in the Pacific Northwest.

(I remember helping the IOR measurer drag the main back to a position aft of the mast for the flotation measurements. It was a two-ply dacron sail and too heavy for both of us. We got it to the front side of the spar and called it close enough. That would have been in about 1972-73.)

[gypsiemarine]

Mate, go down to the marina and have a look at all the masts. 95% aluminium and 5% wood. There is a reason for this.

[DanishBagger]

Originally Posted by gypsiemarine

Mate, go down to the marina and have a look at all the masts. 95% aluminium and 5% wood. There is a reason for this.

Yup, that reason is extruded aluminium, resulting in easier mass production

[CORMERAN]

To TUREDOGAN:

The Designer is on the right track - as far as I am concerned.
If wood came out of a lab. it would be called a "wonder" material.
It will endure many more flexing cycles - than most metals.

- The amount of fiberglass is not the first concern.
- Consider that: - fiberglass resin is POROUS.
- Whereas EPOXY is not.
- Also the glass does not have as much fatigue resistance as the woods
preferred to make masts. So - long term it's not really adding much strength.
- To me, the main function of the fiberglass, is to help build up a thick
layer of epoxy. Which is doing the most work in maintaining the
longevity of said mast.
- Also, the glass gives abrasion resistance.

However, be warned.
Making a mast requires diligence and skill. A small flaw has generaly,much greater consequences - than a similer error in the construction of the boat
it's self.

There are good reasons why marinas are filled with boats with
aluminum masts. It's really a challange to do as good a job as the professionals.

[glenville]

My brother recently built a mast for a 34 ft. sailboat using layers
of fiberglass outside a mold. Its not been sailing yet but seems
plenty strong and relatively light. He can sit on the 40 ft mast when its
sitting on workbenchs at the ends!

I'm finishing a Roberts 31 and have a 47 ft alum. mast I'd like to cut down
to size but think it might be to heavy in the end. It's aprox 6x8 in.. Anyone
have any thoughts on cutting shorter an aluminum mast?

mark

[FAST FRED]

Anyone
have any thoughts on cutting shorter an aluminum mast?

No problem although you will need to relocate the spreaders for the new overall hight, as well as any lower shroud or inner forestay mounts.

No big deal. The slightly heavier mast section may even give a better ride than a super lightweight mast .

FAST FRED

[CORMERAN]

To GLENVILLE:
Re: Fiberglass

Yes, one can make a case for fiberglass masts.
They are actually very common.
Although, many people will not have noticed, as they are covered up
by the sleeve of a WINDSURFER'S sail.

However, please note:
Technicaly, the top of the line, windsurfer mast is very sophisticated.
It is vacum bagged - over a steel mold - and cured by hot steam being
injected INSIDE, said mold.
The resin often used is: air craft grade, epoxy.
If memory serves, the carbon fiber masts made this way, have 18 layers of carbon, within only a 1/4 " of wall thickness !
So dense, that if you drop one on the shop floor - it will a make ringing sound
- just like metal will. - And one suspects, will also transmit electricity.

Cutting down a mast - moves one, closer to an off - shore cruiser. A good thing, from a safety point of view, many will agree.
- In terms of you ending up with the new mast, being, in theory
- a bit more heavy than ideal.
I would, personaly, cut off - the heavier, bottom end of the mast. That is,
if the mast you have, is tapered to any significant degree.

What ever you do - it is advisable to make use of a Marine Engineer's
services.

As I've stated - small errors, in mast constuction - can have major consequences.