Wood Choice for Spars

When I built Shackleton, I used VG Doug Fir for all the spars.  If I build another Scamp, I’m considering splurging for Sitka Spruce.  At double the cost, you might wonder why anyone would choose Sitka Spruce, at least I did.  Is it just tradition or are there beneficial characteristics to using Spruce over Doug Fir?  And, are these benefits real or perceived?

Here’s what I’ve learned:  Both woods are light, strong and very suitable for spar application.  However, Sitka Spruce is 18% lighter than VG Doug Fir per unit volume. Is this significant?  Consider this:  If your mast weighs 20 lb. while using VG Doug Fir, that same mast would weigh 16.4 lb. if you used Sitka Spruce.  To me this is very significant.  Anytime you can reduce weight aloft, you should, especially on a sailboat.  Think of the lever arm extending up into the sky that the mast represents.  A little weight at the top end will have significant effect due to it’s height and leverage.  The lighter weight benefit becomes even more significant if you make the yard out of Spruce, after all, it’s higher than the mast.

The lighter weight will also make stepping the mast easier, and raising the sail.

For these reasons, I’m leaning toward Sitka Spruce.  Another note on VG Doug Fir:  I had trouble routing VG Doug Fir on my last build.  The wood splintered badly and the tendency to splinter seemed unavoidable.  In searching the internet, I found this is a very real problem unique to VG Doug Fir.  My experience mirrored those found on wood working forums.

So, there you have it:  VG Doug Fir at $4.80/ft or Sitka Spruce at $7.93/ft?  I’m going Sitka all the way.

 

 

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3 thoughts on “Wood Choice for Spars

  1. One thing I always wondered about is the weight savings of a birds mouth hollow mast verses a solid or solid laminated mast? Particularly on a small SCAMP type boat. Isn’t the weight displaced by the hollow core the equivalent to a couple of hockey stick (Canadian reference eh) shafts? That said I will be building the birds mouth mast because it look like fun. Randy

    • Randy, I can’t answer your question with definitive data, but I think the weight difference would be several pounds. The mast for Scamp is 3″ diameter by 16’4″, so it’s a very large chunk of wood. My last mast wasn’t planed down as much as I could have…it looked more hand hewn, and hence had more heft than needed. It was also heavier than I expected. So, next time I’ll use Spruce and planing it down to the minimum amount needed for finesse and light weight handling.

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