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View Full Version : Why not Sitka spruce for a neck?



Matt Clara
07-02-2016, 06:21 PM
I've a bunch of the stuff on the rack, mostly for sound boards and bracing. It's heavier than Spanish cedar, but not by a lot, and I can't source Spanish cedar locally and so costs a good deal more. I was thinking Sitka spruce might very well be stronger. Nobody ever made a monstrous big plane out of Spanish cedar.

Ken Franklin
07-02-2016, 09:51 PM
Should be fine but might be prone to denting though no more so than spanish cedar.. I'm doing a port orford cedar neck right now and it's fine too, but is also prone to denting.

Matt Clara
07-03-2016, 01:35 AM
I actually am about to start making my first neck from Port Orford cedar. It's going to be a long-neck tenor and I was thinking of stiffening it with Sitka spruce! I was reading up on Sitka, wondering how strong it is and thinking of the Spruce Goose. Found articles saying Sitka spruce is used in small aircraft propellers, even, which is what made me think, why not just use it for the whole neck?

printer2
07-03-2016, 02:04 AM
http://i406.photobucket.com/albums/pp142/printer2_photo/Guitar%20builds/Art%20Guitars/Softwood%20guitar%2001_zpsmqbefuji.jpg

http://i406.photobucket.com/albums/pp142/printer2_photo/Guitar%20builds/Art%20Guitars/Baking%20Pine%2003_zpsmhwr4obc.jpg

http://i406.photobucket.com/albums/pp142/printer2_photo/Guitar%20builds/Art%20Guitars/Baking%20Pine%2004_zpsg56qtv8a.jpg

http://i406.photobucket.com/albums/pp142/printer2_photo/Guitar%20builds/Art%20Guitars/Baking%20Pine%2011_zpsymmfzue5.jpg

A mighty fine 2'x3' contributed to the neck. Bought a pine board and resawed it but I think it was spruce also. I don't knock it about so no dents to the neck. Will make another one someday.

Matt Clara
07-03-2016, 02:14 PM
I decided to do a direct comparison of Sitka spruce to other common neck wood*:




Spanish Cedar
Sitka Spruce
Port Orford Cedar
Honduran Mahogany


Stiffness
1,323,000 lbf/in2
1,600,000 lbf/in2
1,646,000 lbf/in2
1,458,000 lbf/in2


Bending Strength
10,260 lbf/in2
10,150 lbf/in2
12,290 lbf/in2
11,710 lbf/in2


Average Dried Weight
29 lbs/ft3
27 lbs/ft3
29 lbs/ft3
37 lbs/ft3


Hardness
600 lbf
510 lbf
590 lbf
900 lbf



You can see there that Port Orford Cedar is the winner with regards to Stiffness, which is an indication of how much it takes to make it bend. It makes sense then that it also wins with regards to bending strength, which measures how much a wood deflects (bends) under pressure until it breaks. With regards to weight, Sitka spruce is actually the lightest, and for hardness, the mahogany is quite a bit more resistant to scratches and dents than any of the others. Between Sitka spruce and Spanish Cedar, Sitka has the edge, but Port Orford cedar seems better yet, and Honduran Mahogany has many nice characteristics for necks--better than most in some cases, but it's heavy.

*I'm not an expert on wood testing--I think I have an overall grasp, and that's about it. Data is from the wood database online. wood-database.com

Moore Bettah Ukuleles
07-04-2016, 07:51 PM
I actually am about to start making my first neck from Port Orford cedar. It's going to be a long-neck tenor and I was thinking of stiffening it with Sitka spruce! I was reading up on Sitka, wondering how strong it is and thinking of the Spruce Goose. Found articles saying Sitka spruce is used in small aircraft propellers, even, which is what made me think, why not just use it for the whole neck?

Just as an aside, I believe the spruce goose was made almost entirely of birch. They probably couldn't find anything clever to rhyme with birch.

Matt Clara
07-05-2016, 12:34 AM
Lol, thanks, Chuck. Birch necks it is! ;)

aaronckeim
07-06-2016, 10:13 AM
Hey Matt- We have done a few hundred ukes with Port Orford Cedar necks with good results. I can certainly see sitka spruce behaving the same way. Despite what the above chart says, I can assure that it can be more flexible than mahogany. It depends on grain direction and how tight the grain is. We put carbon fiber rods in the necks, but you still want to make sure that you don't introduce too much relief when you add the fingerboard. Also, I set the action at .075 at the 12th fret but string tension brings it up to .085 or so. Mahogany I set it at .080 and string tension gives me .085. I could imagine laminating two pieces of sitka with a stiff center stripe like banjo builders do. That would also yield a stiff but light neck.
Cheers
Aaron

Matt Clara
07-07-2016, 03:22 PM
The more I read about port orford cedar, the more I like it. I just wish I liked the smell as much!

resoman
07-07-2016, 06:02 PM
I've probably done ten ukes with Port Orford cedar and I just really like using the stuff. It finishes out so nice, really don't have to pore fill and I even love the smell, sorry Matt, LOL

Matt Clara
07-08-2016, 05:46 AM
Where do you guys get your port orford cedar?

ProfChris
07-08-2016, 11:51 AM
I made a couple of necks from pine, which has similar characteristics. These had a hardwood insert to stiffen them. They worked fine, but:

1. Were more flexible than sapele or Spanish cedar, even with the lamination.

2. Were really hard to carve cleanly cross grain, particularly the heel.

3. Dented really easily.

Number 2 was the biggest drawback. 3 was a pain but manageable.

In functional terms the necks worked fine.

resoman
07-09-2016, 04:43 AM
Matt, usually LMI