how to's "building a wooden sailboat mast"

[fishweed]

The lenght of the mast is appox 30 feet, it will go on a motorsailer, first, what type of wood, and are there any sites where I can look at some construction ideas?

Mark

[Crag Cay]

Have a search on here and google for 'bird's mouth' mast construction. There are loads of sites that will tell you all the basics and people on here will be more than happy to fill in the details.

[timgoz]

The ultimate wood for masts and spars is Sitka Spruce.

Check A.L. Condon. Good stuff is getting harder and harder to acquire.

Like Crag Cay said, Google "wooden masts" & there should be alot of information. If you familerize yourself with the basics & differing construction techniques, you can direct more specific questions to the forum members.
It will also give you better judgement when dealing with the info supplied by forum responses.

A couple of good books on wooded boat contruction would be useful if they have sections on mast constrution.

Take care.

TGoz

[PAR]

There are a number of ways to skin a cat or stick as it may be. Sitka spruce is a well loved spar building material, prized for it's light weight and compression strength. Many masts have been constructed from this evergreen. It's particularly well suited to solid masts, but in my opinion, isn't the best material for larger masts or for use on cruisers. Because of it's status as pole building lumber, I've offended a bunch of traditionalists, but that's not such a new thing either. In racing boats, beachable and light weight craft, this wood makes at lot of sense. In heavier, larger, off shore vessels, it isn't my first choice in hollow mast material.

A step by step guide will generally have to be purchased, but a good overview can be had from a number of previous threads on this forum. Use the search tool and some key words will be birdsmouth (as mentioned) spars, masts, etc.

[timgoz]

PAR,

What would be your first choice(s) of wood for hollow mast construction?

TGoz

[Eric W. Sponberg]

If you look at the structural properties of various woods (high strength and stiffness for light weight, known as specific strength and specific stiffness), three woods rise to the top--Port Orford Cedar, Douglas Fir, and Sitka Spruce. Sitka spruce is the generally favored one because of its light weight and plentiful supply. Port Orford Cedar is rare and hard to come by. Douglas Fir is quite acceptable. All these woods accept modern glues like epoxy quite readily.

"Skene's Elements of Yacht Design" by Francis Kinney offers a whole chapter on the engineering of spars, particularly in wood. I am sure if you looked back through Woodenboat magazine you would find all manner of articles on spar design and construction. There may be other books on the subject which you can scan through at www.bluewaterweb.com.

Eric

[PAR]

A generic answer would be Douglas fur for a serious cruiser stick. A racer/cruiser should think about aluminum or other materials. If the yacht forces the use of wood and performance is desired, then Sitka.

[BOATMIK]

Originally Posted by Eric W. Sponberg

"Skene's Elements of Yacht Design" by Francis Kinney offers a whole chapter on the engineering of spars, particularly in wood. I am sure if you looked back through Woodenboat magazine you would find all manner of articles on spar design and construction. There may be other books on the subject which you can scan through at www.bluewaterweb.com.

Eric

Great suggestion Eric.

Skene's has both the method and a worked example in the back.

Also the rectangular masts in Skene's can be made much lighter than a birdsmouth mast - purely because the rectangular section has a higher second moment of inertia - is stiffer for the same weight

It is also easier to build - fewer parts.

And fewer parts and lighter weight for the same stiffness mean less material - so it is cheaper.

We have been doing some work on thinner wall section rectangular masts and it seems that with modern glues it may be possible to go down to thinner wall sections than Skene's suggests. But for the motorsailer the standard 20% wall is a good balance of robustness and cost.

Michael Storer

[fhrussell]

Here are some links to basic info.... it may be helpful....?

http://www.everything2.com/index.pl?node_id=1400819

http://users2.ev1.net/~fshagan/mastm.htm

....and one of my favorites....
http://www.starclassics.org/Sliding_...making-of.html