Official Luthiers Forum!

We always have so much to be thankful for. Today I'm starting my 68th trip around the sun. Thank you Lord!
But the featured blessing today goes like this. 2 weeks ago, Brent Jr. opened up a salvaged log and dissected into guitar block. Ryan Dissected the block into various Tops and bracewood. Last week Annette and I ran it through the wide belt sander, and I brought down to the grading room to start going through today.
First boards I grabbed and I said to self, "They seem pretty Light". Yepper, they are! And not only are they light, they are ABSOLUTELY gorgeous! And it's straight. WOW!
What a blessing for sure. About 400 sets. I asked Brently, if any of this log remains. He said we had the butt log left and maybe half of it, from the small end will produce more tops. The big end where it's approx. 48" diameter is riddled with pitchy tumors. So no guitar tops there, but may get some great split face bracewood.
This tree was prospected in January 2016 after a storm that caused widespread landslides and blow downed trees. The guys cut their way toward Polk Inlet, hound dogged miles and miles of brush for 4 days in more stormy torrential rainy weather and found 18 trees scattered off of various logging roads. Both New blow downs and old ones.
This was an old blowdown, that may have been down for 20 yrs or more.
Anyway we logged the sale July of last yr.
The newest tree blown over in this timber sale is one pictured in that Video in our web site, Blog page, titled "A day with the crew of Alaska Specialty Woods"

Light density and stiff. Density comes in at 23.2 Pounds per cubic foot.
Yahoo mountain dew!
Brent told me which setting, and I found pics of the tree after it was logged and loaded.

Nice! And Happy Birthday! I'm on my 67th about to hit my 68th.

Dave

Happy birthday!

Happy Birthday and happy spruce! Those look beautiful.

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jw ( o)===:::

>Light density and stiff. Density comes in at 23.2 Pounds per cubic foot.
To compare density of this material and the rest of our UL sort to standard density old growth sitka,
Most of the sitka we cut that I will just label standard density, is 27-30 Pounds per Cu ft.

Great looking wood Brent. Thank you for what you do and hopefully you have a succession plan for twenty years or so down the road!

Thank you Darrel. 2 generation, i.e. Brent Jr and Ryan are the ones doing most of the “labor” these days. I still do all the business, the grading, sorting, Marketing and hauling with the self loader[i’m the only one with the cdl]. Started driving truck, hauling logs, when I was 19. And 3rd Gen. is on deck. Grandson Owen is 7 and B-3 is 3.

Happy birthday Brent!
You are blessed to have good health and family around you. Wishing you many more years to come.
That is some fine looking tone wood.

I would like to hear from those of you that test and are very analytical of soundboards/tonewoods, specifically about density.
Alan Carruth comes to mind.
I'm only somewhat familiar with Bryan Gallup's dynamic evaluation process. He demonstrated the program at a NAMM show a number of yrs ago. and has explained it to me. I would agree with him that longitudinal stiffness/and strength is the most important because of the stresses from the strings. I don't have apparatus or time to test that dynamic. But I know cross board stiffneess and most of that is in relation to the orientation of the cut with just some variations from tree to tree, or quadrant to quadrant of the trees.
I can tell by handling the boards of the dimension we produce and stock on the shelves/pallets, that the light w density/weight are so much more tonally responsive.

Right now a bookset of our boards dimensioned at 23 x 9 x .185, most sitka will weigh 18-20 ounces. I've set the dividing line between light and standard at 16 ounces. But I do allow a .1+ just because our boards are not perfect. There can be an 1/8" drift in the width, over the length and there can be .005-.01" thickness difference from side to side in the width as the sanding belt wears between changes. I can have boards from the same cutting, and you know they are the same fiber and the boards are weighing 15.7-16 and then a couple 16.1. It's there, but splitting hairs.

So my question is, when good to excellent stiffness is a given factor, where would you draw the line between standard density of my sitka spruce and the special light density wood that i come across on rare occasion?
Am I thinking correctly the way I'm sorting now?
In pounds per cu ft density, I'm setting aside tops with a lb/cu.ft. density under 24. and most other seems to be 27-28+.

Though I've produced well over a million tops in 28 yrs, I'm interested knowing more in this regard.

also How do these number compare to norway spruce and the lutz hybrid?
Though both of those species of spruce are softer than the hardest of the soundboard spruces- sitka
Thanks in advance.

27lbs is the wood data base average density, or .425g/cm3.

I’m sorry but I’m gonna have to go metric on you…

I think 24lbs/ft3 is about .38g/cm3? If so, I would consider that to be a bit lighter than average sitka. If 24 is your high cutoff, I think you’re about right to call anything under that that super light, for sitka.

Most of the lutz I get these days is on the heavier side from what I used to get, from .36 - .38 average, but I’ve had lots that was well above .40, and the stuff I used to get back in the good old days would usually be in the .32 - .34 range. So I have hundreds of measured examples between .32 and .44, but the majority in the .36 - .38 range…ish these days.

The only two pieces of Picea abies I have in stock both measure at .31, but I did ask for the two lightest pieces available. Sadly I could not also afford the two heaviest…

Just got word from the person I bought those Picea abies tops from, and apparently they have some at .406g/cm3…

Why the desire for the very dense softwood?
I’ve seen Very heavy dense sitka too, that i’d believe would compare to oak.

Horses for courses. I like dense woods for some guitars and less dense woods for other guitars, and it’s a very deliberate design choice to pick top A over top B for guitar X.

I talked to the supplier and he says they have definitely seen Picea abies at .44 range.

So both lutz and picea have a range of .32 - .44, a pretty broad range.

Anyway, you asked for numbers and the numbers I gave are verified. I’ve measured the density of every one of the last 350 guitars over the last 15 years, and have the log sheet for each, except for the occasional one I’d forget to measure while being in a rush.


My overall takeaway is that you really can’t rely on getting a top in a certain density range by buying a particular species of spruce. It all comes down to the individual piece.

But more to the point of your original question…I think your weight cutoff at 24 is sound judgement, pun intended!

Brent, DaveO posted an attachment at the bottom of this post over on the ANZLF. Units are metric but it should help you figure out what is low and high density for various species. There's no data on picea abies, though.

One "measure of goodness" of top wood is the sound radiation coefficient. There's a chart for various spruce species, including Engelmann, European and Sitka on Page 9 of this paper.

...and Happy Birthday!

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Sorry to be so long getting into this thread.

Low density softwood tends to end up making a lighter top when worked to given long-grain stiffness. This gives more sound and quicker response, all else equal (and it never is..). Denser wood tends to give more 'headroom': it seems that you can drive it harder without the sound 'breaking up'.

Most of the Sitka I've tested has had a specific gravity between .4-.475 (25-29 lb/ft^3). Euro tends to be a bit lighter, and Red a tad denser, maybe. I will say that the densest spruce I've tested was Euro (~400 years old!) at around 34 lb/ft^3. WRC runs down as low as 20 lb/ft^3. There's a lot of variation within any species, of course.

A number of folks have sent me emails or msg via our contact us form from our website.
I have replied to all of the inquiries. Many of the replies have not been read, as reported by my email tracker that monitors opens and reads.
So I suspect that my replies to those folks have gone to their spam or junk folder.
I need to monitor my spam folder daily to watch for important customer dialog that get sent there by even my “very weak, setting” spam filter.
Anyway, what I’ve written to folks is that this light density sort is a “variation” that is in the non-figured dreadnought guitar top product listings. Grades 1A-Master grade. Master grade having the most even color and texture and strong medularies. But unlike the top pictured, the top from this last log that we are blessed with, some logs having the same other attributes have had a more open/loose texture. I.e. growth line count.
If ordering any of these tops, specify if there is preference for fine or loose growth lines. There is both.
We also recently[actually several months ago] cut a log that is moderately bearclaw figured that will be added as a variation in the bearclaw sort/s. Just too busy to market it, so they were set aside on a pallet.
I’m on my ipad and cannot downsize the screeshot of the variations, so you know what I’m talking about in this post. So here is a link to that image in a drive folder. https://drive.google.com/drive/folders/ ... ANzXBBbKTe