trees to spars?

[Daniel T.]

I am gearing up to build a sharpie or modified and am getting my ducks in line. My question is this, I have ten acres of forested mixed species. can I build my spars from whole spruce?
Thank you Daniel

[Bob Smalser]

It's done, but not the best practice, as you'll be fighting splitting/checking the entire life of the spar.

If you can split with wedges/froe or bandsaw one of the clearer trunks down the center, you can make your spar out of either half so there is no pith or heart center present. Cut off all sapwood, too. Machine it green a bit oversize and stuff it up in your garage or attic joists to allow it to season before taking it down to final dimension. Spruce dries well and easily.

Wood shinks twice as much in drying tangentially as it does radially....in a whole log section you can easily measure the difference for that species by the width of the splits.

[ 10-11-2004, 10:27 AM: Message edited by: Bob Smalser ]

[Jack Heinlen]

On the opposite side. Though Bob is right for the reasons he mentions about it not being ideal, it was common practice in workboats to take whole trees and make them into spars. Straight, close grown spruce would work fine.

If you are shooting for a yachty finish I'd pass, but if the spars are to be oiled, and you can live with a bit rustic, there isn't any functional reason not to. See George Buehler's Backyard Boatbuilding for a brief discussion.

[Ken Hutchins]

If your trees are on the north side of a hill, they will not check as bad as trees grown on the south side due to slower growth. Best to harvest at the end of Jan. or the first 2 weeks of Feb. when moisture content is the lowest. Black spruce would be the preferred species.

[Daniel T.]

The trees are in central Maine, very near the Penobscott, and are any where from 12" to 18" in diameter at the butt. I worked as a logger for many years so it is now embarrassing to admit that I do not know the exact species of Spruce. However the splitting of a large enough tree could provide me with both spars. And also other asorted parts. So the question becomes, are the Spruce that are indigenous to Maine of spar quality? Thank you all again for you thoughts.
Daniel

[Bob Smalser]

If your spruce is straight, clear, FOHC and all heartwood...

...I don't think species matters much in a small boat...the differences in strength and stiffness between the species is negligible. No spruce is durable, however...all of it needs protection from the elements.

[ 10-11-2004, 08:26 PM: Message edited by: Bob Smalser ]

[Daniel T.]

You(Jack)talk of close grown Spruce. I understand that to mean trees that have grown from start to preasent in runs of like species, tightly together with long, straight, narrow stalks? thank you again.
Daniel

[Jack Heinlen]

Daniel,

I'm no forester, but when I spoke of close grown I meant grown up since sprouts with more mature trees, of whatever species, close by. It's the way trees grow in virgin forest, or in second growth that has succeeded for a while. This means the tree grows for the light quickly leaving a relatively branchless trunk, and so fewer knots.

I've got half a dozen nice-sized white pines that I suspect sprouted shortly after this land was originally cleared, and so are open grown. I look at them, occasionally, with an eye to house lumber. They'd likely be fine for sheathing, sub-floors, maybe even a timber frame, but the butt logs aren't going to be anything like clear. Before I made a decision on cutting some of them I think I'd get a real forester to give them the eye.

Back to the original question, relatively clear trunks would be preferable. Though in my travels around the Chesapeake, years back, some mighty gnarly trees had become spars in the skipjack fleet.

Where are your trees located? You might be able to get a professor of forestry, or grad student, at U of Maine Orono to look over your spruce. Present it as a class project and you'll get a dozen opinions, be better informed, but right back where you started. ;)

Good luck. Let me know if I can help.

Jack

[Frank E. Price]

The mast in my 18' workboat-finish sharpie skiff is a grown Western red cedar stick. It's not something else only because the day I went looking for a tree it was the straightest one I saw of the right size. I expected it to bust in a season or two, but it's still going strong after 3+ years. Not much checking. I floated it in the bay for a month before I skinned it.

Frank

[Bruce Hooke]

In my experience Maine spruce tends to be pretty knotty so you might have to cut down and open up a couple of trees to find a good one. Clear (enough) Maine spruce can be found. I have a nice 12' canoe pole that came out of a spruce tree cut on my cousin's land in Maine.

[lagspiller]

I have a solid wood mast on my 22 sq.m. I had a Sitka turned down on a lathe last winter by a guy who specialized in flagpoles, but had made plenty of masts. He apparently has made masts for lots of the heavier boats (skoyter - like Colin Archer style) Mine is about 36' long.

I am now finished with the first season with the new mast, and I am very happy with it. Functioned well, looks good. Some 'checks' (if that means longitudinal cracks) - but the common wisdom here is that they have no bearing on the strength of the mast.

My only advice is to perhaps add a little to the diameter you have the mast turned down to... in case you do have some shrinkage as it dries.

[TimothyB]

I recall an article I read about splitting smaller logs for use as spars..

The diagram showed the log being cut into perfect quarters, then the quarters reversed, 45 degree bevels cut in to the arc sections so that when glued up she was square. Then rounded off as per normal.

I'm assuming as well that the sapwod was removed, although for light spars you probably don't have to worry about it.

Here is a poorly done but I think reasonably obvious example drawing of what I recall.
http://www.ennui.net/~timothy/Boats/squarespar.gif

Although my drawing does not show it, there is a small gain in diameter from the original solid spar.

Your mileage may vary. This is probably not as strong as a bird's mouth spar, but it seems that it would be at least as strong as a box spar.

[J P]

You could try to limit the checking by ripping the log down one side, probably to the pith would be best, and wedging it as it dries. The idea being to force/limit the check to one place and compress the rest of the fiber as it dries. Then you could clean up the rip/check and fit a filler.

[Chris Coose]

Ralph Stanley of Southwest Harbor has been trimming big trees for his boats for a long time now. Take a ride down. He is usually obliging.

[PeterSibley]

I've cut and debarked 5 trees for spars,I won't use then all ,just pick the best.They are all plantation hoop pine, an Australain timber that is suitable for spars.Sizes range from 5" to 8" diameter.

One trick I picked up and applied was to run a powersaw cut to the heart of the pole when it was green. As they have dried they opened up uniformly along this cut.On an 8" pole the saw cut opened to around 1/2".There is no other cracking or checks.I plan to glue in a matching strip of timber, I'll have to clean the slot up with a router first .

[Sailing-Randy]

I am almost too embarrssed to add to the discussion, but I thought it might help to have a bottom of the barrel perspective...

I made my mast out of Eastern Red Cedar -listen for the chuckles across the land- a solid spar from a standig dead tree. square in shape. When drying it took on a nasty curve at the top so I cut in a scarf joint and reglued fairly straight. After 3-4 years it is holding up fine and hasn't lost any apparent strength. Still just as springy as ever - which the boat designer thought to be advantageous.

Again, repeat, this is from the bottom of the barrel perspective.

[ 11-16-2004, 05:28 PM: Message edited by: Sailing-Randy ]