Sitka Spruce questions

[Robert Miller]

I am about to puchase a 2"x8" plank of sitka spruce to build a solid round mast - with widest dimension just in excess of 3".
The plan is to rip the plank down the middle and epoxy the two halves to make a 4x4. I plan to reverse - end for end- one of the planks before laminating.

Questions:
1. What part of the tree, and how to recognize it, should I be looking for when choosing the specific plank?
2. How should this plank have been sawn by the supplier?
3. When flipping one half end for end, should I also turn it over (reversing the grain with respect to the other half in this aspect as well)?

Thanks for any advice.

Robert

[Tad]

Robert,


Gee, lots of spar questions this morning, must be that time of year. See my other answer in Open Discussion.

With any lamination more small pieces is better than few large pieces. The smaller the bits, the more stabile your structure. What are you bonding with? Is the spar point loaded, that is are there gaffs, sprits, shrouds, stays, etc?

You want an edge grain piece of wood; the people selling it should know what that is. The grain will run roughly, +/- 45 degrees from the face (wider side). This is called Quarter Sawn, the lumber guy may roll his eyes when you ask for it, pay no attention. You do not want flat sawn, where the grain runs parallel to the face. But this may be all you can get. In that case rip it into 3/4" strips and build a "birdsmouth" hollow spar. See Woodenboat for references.

Is your stock really 2" (8/4), or is it something less? If it was an honest 2" you could cut it into 3-4 pieces and use a 2" by 6". Build a box with sides about 7/8" by 3" and a core of two strips roughly 1 3/8" by 1 1/2". Don't worry about end for ending but do balance the grain direction, opposite, when looking at the butt.

All the best, Tad