A question of Spruce

[Johnny K]

Originally Posted by charles Tauber

To be clear, "silking" is NOT the same thing as "bear claw". Silking is visibility of the medullary rays: bear claw is a localized anomaly of the growth rings sometimes found, particularly, in Sitka spruce. (Despite urban legend, it has nothing to do with bears.)

This piece of wood displays both "silk" and "bear claw":



30 years ago, "bear claw" was seen as a defect and wood with it was downgraded and avoided. Today, some pay a premium to buy wood that has it. Fashions.

LOL. I guess Seagull were ahead of fashion when they made "Scarface" back in the early 90's.





I bought this Spruce Deluxe (an S6 with a spruce top instead of cedar) used and it was in pristine (as in, no one played the thing) condition. I bought it for the way it sounded than how it looked. I played every sub 500 dollar guitar in the shop and this is the one that sounded the best to me. It's not quite as good as my HD28V, but I can tell you it gets played more than any of my other guitars. It's rarely in a case and is always not far from hand.

[GuitarPoet1]

Hi I know these posts are older, but always valuable. I have seen a really pretty and awesome sounding Taylor acoustic guitar with a KOA top. The KOA wood has beautiful knots that add to the uniqueness of character to this guitar. However, I am just a little concerned that the top may crack due to these knots. The GC salesperson said there is no concern as it is a Taylor and they would not put forward any product that may potentially be defective. Which does make sense. Nevertheless, I welcome feedback. Thanks....Jo

[Birchtop]

I don't care for the knots myself. I once sent a fender 12 string back because the Sitka spruce top had two knots in it. They sent me back a beautiful, knot-free replacement.

Unfortunately the replacemt didn't sound nowhere near as good when compared to the one with the knots in it.

Finally, on the 3rd try I received a nice replacemt, in both looks and sound. But I will say, the one with the knots in the top had the best sound of the three.

Go figure...

[Alan Carruth]

I believe the function of the 'ray' cells is to transport sap in and out of the trunk in the outer ring of living cells, the 'sap wood'. If you look at microphotographs the rays in softwood comprise small bundles of cells, around a half dozen, and they run, as has been said, along the radius of the tree, perpendicular to the ring lines. The bundles are roughly eye-shaped if you look at the bark side, and they run between vertical structural cells.

All species of wood have ray cells. On something like ebony they're small and hard to see. Oak seems to have two different sizes: I've heard of the larger ones being called 'aggregated rays', and read someplace that they are used to store starch in the winter.

The ray cells do help tie the structure together, and seem to add a little stiffness: flat cut wood, with the annual ring lines parallel to the surface, averages slightly lower cross grain stiffness that perfectly quartered wood. Violin scrolls are cut with the ring lines perpendicular to the side of the scroll to help resist being split by the wedge action of the pegs. The rays also seem to reduce the cross grain shrinkage in well quartered wood. That helps make it more stable and resistant to cracking.

I'm not at all sure that well quartered wood is more resistant to long term deformation due to string stress than other cuts. The higher cross stiffness might help a bit initially, but that seems to fade out as the top 'creeps' into a belly over time.

Acoustically the high cross stiffness denoted by a strong ray pattern probably helps with wide tops (like a Jumbo or Dread), but may not be so helpful on a narrower 0 or 00.

So; IMO, as usual, as a 'make or break' marker for high quality in a top I'm not sure it's all that important, but it has it's benefits.

[1neeto]

My 2004 214 has some nice silking and I guess that’s some bear claw too. Compared to my Japanese guitar from the 70’s which has no silking and it’s darker. Is it more prominent in Sitka spruce?

[Jaden]

Originally Posted by Gomers

I was in a well stocked dealer yesterday having a browse, lots of lovely Martins, Gibson, Taylor, Santa Cruz and what struck me was the amazing looking spruce tops with infinite cross silking / feathering (add your own description here) and it got me thinking as to how this phenomenon occurs.

When I look at my own guitars, my '57 00-18 displays virtually none of this effect with the '65 D18 a little more but nothing like a lot of modern guitars and I started to wonder, Why ? Is there mileage in the notion, trees were really old when my two were made and that younger trees used to make present day instruments, naturally display more of this visual effect. Is it an indication of quality ?

My guess is with the aid of computerized technology, perfectly quartersawn old growth sitka spruce tops show fine, even silking across the entire surface of the (straight) grain, as evidenced on my 2019 Yamaha FS800, and is more common today than ever compared to guitars of the past, when less accurate cuts of less discriminating selections of spruce were employed for guitar tops. I think the spectacular visual appeal has caught the attention of some environmentalists.

[Naboz]

I don't remember this thread...but this place is so informative.
I've learned (been told by knowledgeable luthiers) that the medullary lines are, again as we've seen commented here, examples of well quartersawn tops.
Charles and Alan; thanks for your contributions, you add so much depth to the conversation(s).
I'm fortunate that most of my tops have medullary rays--and I began to think it was because the milling for guitar tops these days is better controlled, and thus more quartersawn tops. I also think it is aesthetically pleasing.
Nice reading.

[gmel555]

I may have missed it but I don't think anyone mentioned the following yet: I few years ago I read somewhere that Adi Spruce will not show nearly as much cross "silking" as Sitka or Engleman do. Ever since, every time I've held an Adi topped guitar (and I own one) I've checked this out and it seems to be quite true. Older Adi tops I've seen did have that cool "sugary" amber "sparkle" but not the cross silking. I wonder if the Op's 1957 00-18 is Adi. Not sure about European Spruce.

[charles Tauber]

Referring to my notes from 2016 and 2017 lecturers by veteran Luthier Sergei de Jonge, Chris Martin stated that prior to the 1970’s, Martin didn’t really care about the species of spruce they got, they simply wanted large pieces. Most of what they got was red spruce and white spruce, largely From the Adirondacks. They cut their own tops and chose to cut them a few degrees off of quartered for the reason of increased resistance to cracking. Given that one only see’s silk in tops that are exactly on the quarter, That might explain why Their older guitars don’t display a lot of silk.

I have no evidence to either support or refute that slightly off quartered wood is more crack resistant than well quartered wood.

The appearance of silk is a mechanical property of the wood and does not become less visible with age.

How well quarter sawn a top is is only one factor in Assessing the quality of a top.

Generally, well quartered spruce shows an equal amount of silk, regardless of type of spruce: no one spruce has more apparent silk than another.

[redir]

Originally Posted by GuitarPoet1

Hi I know these posts are older, but always valuable. I have seen a really pretty and awesome sounding Taylor acoustic guitar with a KOA top. The KOA wood has beautiful knots that add to the uniqueness of character to this guitar. However, I am just a little concerned that the top may crack due to these knots. The GC salesperson said there is no concern as it is a Taylor and they would not put forward any product that may potentially be defective. Which does make sense. Nevertheless, I welcome feedback. Thanks....Jo

Knots are definitely prone to cracking so you have a valid concern there. Pics would help. I can't imagine Taylor releasing a guitar with knots in it. Perhaps they are just pin knots or some other feature?

I built one folk art project guitar out of barnwood that had big knots, about 1cm, in the top and I flooded the knots with thin CA glue. Going on at least 5 years now and I've not had a problem. But it's definitely a weak spot especially in that size.

[jim1960]

Originally Posted by Wade Hampton

Now you all have me curious; I’m going to have to go check the silking on some of my older instruments. But my distinct impression is that silk in a guitar top doesn’t fade or go away. I don’t know of any process whereby it should.

I've never heard of medullary rays fading over time. Take a look at an old oak floor and you'll see them still prominent a century later. If they appear to fade on a guitar, I'd bet that has something to do with the finish changing color.

[RP]

Originally Posted by GuitarPoet1

...The GC salesperson said there is no concern as it is a Taylor and they would not put forward any product that may potentially be defective. Which does make sense. Nevertheless, I welcome feedback. Thanks....Jo

Jo: Welcome to AGF. I'm a longtime Taylor fan, and their customer service is second to none. However, any company is subject to problems - the big thing for me is how they deal with those problems. Taylor, like any other company, will make mistakes but tends to knock themselves out to rectify issues.

Case in point, I purchased one of the early Revoiced 814s that were made in 2013. When I owned it, one of the top braces came loose. I returned it to El Cajon on their dime, and they removed the neck, rebuilt a new box and returned it to me several months later. Turns out that some of their earliest attempts at using "protein glue" on the early Revoiced models were problematic although I never saw this in writing anywhere. They could have sent me to a Repair Center and had the faulty brace reglued, but they went far above and beyond to rectify the issue.

That said, I think your salesman probably told a half truth...

[Alan Carruth]

Charles Tauber wrote:
"I have no evidence to either support or refute that slightly off quartered wood is more crack resistant than well quartered wood."

I don't know about 'slightly off quarter', but 45 degree skew cut is certainly more crack resistant the well-quartered. It also has the lowest cross stiffness. Perfectly quartered soft wood stock might be ten times as stiff along the grain as across, and dead flat usually runs closer to 12:1. Perfectly skew cut, with the ring lines at 45 degrees, can have a stiffness ratio of 100:1. I've seen skew cut tops that could probably be wrapped around a soda can without breaking. Cross stiffness drops off measurably with even a very slight departure from 'perfect' quartering, to the extent that adjacent cuts from the same board can have cross stiffness that's different, even when you can't see much difference looking at the end grain. The ray pattern will show it, though. It's one of the (many) reasons that it's about impossible to make 'identical' guitars that sound the same.