Official Luthiers Forum!

There are so many types of spruce.

Sitka Spruce
Red Spruce
European Spruce
white spruce
Engelmann spruce
and many more...

Then there are the the different grades of spruce and age of it.

But when it comes to buying it for our use, how tight should the grain be. I've seen some people selling spruce with only 12 rings per inch. The violin wood i used to buy had a minimum of 25 rings per inch and some times as high as 35 that i've bought and have. I would of never thought of buying a violin top with less then 25 unless it was just for carving practice.

So for those who buy it for custom made guitars, what is your favorite spruce to use?

What is your minimum requirement for the number of rings per inch?

Also how many years of curing, before use?

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Disappointment is an empty box full of expectation

They all have different looks and sounds. I could suggest you to check the descriptions on LMII website, they are good.
And for the grades, the wood is classified in grades from many specifications, aesthetic and tonal. (Figures, grain thightness, colors, sound clarity, sustain, harmonics, etc) And every supplier has his own classification system, you have to check! Sometimes it's only aestethic and you can grab a AA soundind as well as a mastergrade.

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Francis Richer, Montréal
Les Guitares F&M Guitars

I have to say that while I love good red spruce, and "real " German is fantastic for mandolins, for guitars I have been enamored lately by grade A, very stiff Engelmann with compression stripes and no brown streaks. It looks like red, and makes a very good sounding, old timey looking guitar when braced right. It has some of the attributes of German also. It's got to be awful stiff though and I go through 20 tops to get 5 good ones. It doesn't have the look of Wonderbread that most Engelmann AAA has either. That homogenized whitebread look doesn't do it for me.
Would love to get my hands on some A or AA Swiss spruce though...
As far as grain count, I'd rather have a wider grain, 8-16 is good for me. I usually sticker it for at least a year in the shop before I'll even consider using it.

Hi Mark - here are my own answers to your questions:

Q) How tight should the grain be?
HA) For me I am less concerned with the number of grain lines as I am with the overall stiffness of the spruce. A number of spruces are good examples of wide grain spacing, in some instances, but still excellent tops and these include but are not linted to Carpathian and Adi (Adirondack). There are some discussions in the archives on this topic and a search may yield some interesting reading.

Q) My favorite Spruce to use?
HA) That's like asking me if I prefer blonds over red heads - I love them all..... Seriously if I was made to live and work with only one spruce going forward is would be Lutz from Shane at High Mountain Tonewoods a sponsor with a link above. I have found this incredible wood to be as versatile as anything out there.

Q) Minimum requirement for rings per inch?
HA) I don't have a minimum again because overall stiffness is more my concern. How do you know the stiffness prior to having the wood in your hand? You have to trust the vendor to only send you good stuff - all OLF sponsors are good folks to do business with in my humble opinion and this is based on personal experience, positive personal experience.

Q) How many year curing before use?
HA) The more the better. For drying before use the general guide is 1 year of drying for every inch of thickness. Most of us stock tops in our shops well in advance of the anticipated need. Many of the vendors will also be happy to tell you how long their offerings have been in stock with them too.

I hope this helps and "HA" stands for Hesh's answer which is not intended to be anyone else's answer - just my own answer.

What Hesh said !
Mc

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Mike Collins

I find that rings per inch are more cosmetic than assurance of quality. Often the wider ringed wood is higher in stiffness than tight grained Also wood selection should be on what you are trying to accomplish . A loud blue grasser would be different from a fingerpicker . I use more red spruce but find the alpine spruces good . Carpathian , Lutz are also good. Sitka is an old stand by . I heard a guitar made from norway and blue spruce and they sounded very nice .
Lets face it , there is more than just the top wood involved , bracing will also play a part . All the wood selection just adds more to the palette and allows a builder more flexibility to match the build to the client.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

To add to the great comments above, I've learned (from those who've already commented above, as well as others), that there are two factors you definitely want to avoid in tops -

a) tops that are not almost perfectly quartersawn - anything off quarter will affect stiffness, and is definitely not ideal.
b) tops with runout - which also affects stiffness, and structural integrity as well. Visible as a difference in the way the top reflects light, when viewed on an angle. I suppose that a certain amount of runout is inevitable, but others on the site have already commented on what degree is acceptable for building. Should be in the archives.

What I've also learned that you really need to do deflection testing for stiffness, as every piece of wood has a different level of stiffness and density, regardless of species. Consistently thinning your tops to .110", for example, will certainly result in tops of varying levels of stiffness, and thus different acoustics.

Ti-Roux, Thanks for the link, It was good to have a description of each type. I've been looking at getting a pallet of Engelmann spruce. I've liked it in the past for violins but had no idea how it compared with other types of spruce.

Haans, one of the things i was wondering about is how uniform Engelmann spruce is. For a violin it is lovely but on such a big surface like a guitar would there be any interest in it. The pieces i have, the grain is so straight, tight and white.... kinda boring, not like the piece of cedar i just bought. By the way I really like your website.

Hesh, I hear a lot of talk about the stiffness and how important it is. How does one know how stiff it needs to be? Is there something to compare it to? or something you learn over time? I mean everyone has different strength so flexing a top could feel quite different to each maker, what would you compare the right stiffness (in your opinion) to? When you say that High Mountain Tonewoods's Lutz is versatile what do you mean? It has a lot of variations or that you can manipulate it to have that certain sound you are looking for? The Engelmann i'm looking at has been curing for 15 years and was cut deadstand. It would be nice to have a stock that i can use right away or relitively soon, and then just let the rest age...

bluescreek, thanks for putting it into perspective, top is only part of the dynamic system it is made into. Well, will give this some more thought, i have some time to make my decision. Thanks so much for all the input. It's nice to get more then just "it's subjective" answers. It's good to know why people think what they think, some times patterns emerge from it.

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Disappointment is an empty box full of expectation

Since most here buy the woods from vendors, best way to get the wood want is buy from those you know and have had good success with. As John H said many times it is just a preference of what one likes, but the bracing and using that specific piece of wood and how it feels that is best. Face it most buy wood unseen, so you take a chance anytime, but chances of getting great wood, spruce of whatever has best success if know who getting it from. I would never hesitate getting from Shane, Bob, LMI and sorry if missed someone, but any of the folks here. Even if picking out the wood from a pile, if not know what looking for in all aspects, one can get good looking but not great wood. These folks make a living out of know what to look for, how to grade it and what to and what not to sell.

Know in one shop worked for, had billets of spruce, maple and other woods. Knew what looking for how to tell if it was usable for tops before and then after resawing is important there. If not great for a top for some reason, then used as the neck and tail blocks, side braces when used, and other things. I was told and found more to resawing than just cutting a hunk of wood. When boss needs more, he actually goes and sorts through the pile and stacks of wood and buys it that way and stores it in shop in billit until starts needing it. More times than not several years worth at a time.

All that to say, buy wood, get a relation with the various vendors here (same folks I guess on other sites also) tell them what you want and you will find more times than not by vast, vast majority of time will be just fine. I like the smaller vendors more than bigger ones just on a personal basis like guys I have noted, because get more personal touch than big guys (although big guys have great stuff and grade it right

Many of us use deflection testing where we set-up a rig of sorts which can be incredibly simple. Decide on a weight to use and test the deflection of a top under controlled conditions and see how much it deflects. This can be done, with care, both along and across the grain. If you check in the tutorials section I think that David Hurd contributed some good toots (tutorials) on his take on deflection testing.

Once you record the data you have the beginning of a database. No one that I know of publishes their data so we all have to start somewhere and record our own data under controlled conditions and in a repeatable and reliable test method. There are lots of ways to do this, as many as your imagination is active.

In the beginning the data tells you very little but in time if you want a particular sound from a guitar and you have had that sound before from another guitar you may want to revisit the deflection data of the top that you wish to replicate.

Although there are certainly those who would be very quick to discount any claims that Luthier has a "feel" for his wood (no jokes please...) although I certainly do not have this feel, yet, it is a goal and a stated goal that I have been quoted saying prior. I always thought that some of the great Luthiers of the past and present must have a pretty good feel when flexing a top, braced and unbraced and this was always something, from the very first guitar..., that I have endeavored to develop in myself. I always tell folks to never miss an opportunity to feel your wood..., flex it, etc and note how it feels to you. THEN I do deflection testing and see how my attempt at an educated guess stacks up against the data. If I am wrong I change the data... just kidding....

You can build a guitar out of nearly any wood including pallet wood as evidenced by Bob Taylor and the 5 or so pallet wood guitars that they built. When I say versatile what I mean is that IMHO with Lutz I can have success in building a dreadn*ught for grassers or a finger style OM. With appropriate bracing and design goals I am finding that Lutz can do many things well limited only by the skill and knowledge of the builder. That is what I mean by versatile.

Stocking Lutz in my shop has never limited me and only offered me opportunities. There are lots of great woods though and certainly Euro and the various kinds of Euro is a great resource to have in your neck of the woods. Lutz reminds me of great Euro.

I ended up getting an orphan/unmatched Sitka top set by mistake...
1 half of the top had the "Narrow" side grain lines at right around 150 lines/inch and the "Wide" side lines at right around 50 lines per inch...

I couldn't even see the grain lines until I got out the 20X loupe... That tree section was approximately 800 years old or so... Such a shame it ended up getting orphaned and being sent back (With the other side having about 12 lines/inch..) It would have made an interesting guitar... I didn't measure it, but subjectively.. It felt "Heavy" which usually correlates to "Hard."

As others have mentioned... My feeling is that you gotta decide what physical properties and cosmetic criteria you want for your tops...

Some folks love super uniform, creamy white tops... Some folks love tight grain patterns, some folks don't care as much about that sort of thing and go looking for the right amount of deflection or crosswise stiffness or whatever....

Thanks

John

thanks Todd Stock
this is exactly what i was wondering about.

and Corky Long i was recently looking at some tops that they were describing degrees of run out and where on the top, it all seemed very technical and i wondered why they went to so much trouble to justify what i thought wouldn't make a good top. The tops sold though and for quite a bit of money to. and i think you summed it up quite nicely with this example :

thanks

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Disappointment is an empty box full of expectation

I never get tired of posting the link to Dana's classic essay on tonewoods:
http://web.archive.org/web/20050308152013/www.bourgeoisguitars.com/tapping_tonewoods.htm
No mention of more recent "discoveries" like Carpathian, Lutz, Caucasian etc. but unsurpassed in its breadth and clarity IMHO.

I never found any correlation between line count and stiffness, certainly not in red spruce or sitka. Sometimes more lines/inch means heavier, but not necessarily stiffer. On the other hand I found that tops with Hazelfichte are consistently stiff in both directions. Off-quarter often means much less cross-grain stiffness, which can be an advantage for smaller guitars.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Hi mike is that a wood rosette?



Absolutely stunning!!!

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Disappointment is an empty box full of expectation

Laurent Brondel, I finally got chance to read through that essay. That has cleared a lot of things up for me!!! Thanks so much for the link. could it be argued then that less lines is better, to the point obviously where it becomes to weak to be beneficial? I was thinking about something i read somewhere that it was like a balancing act between making it weak enough to have the right sound and just strong enough that it doesn't fall apart.

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Disappointment is an empty box full of expectation

IME line count is not related to stiffness. I have a good amount of red spruce with either wide or fine grain, sometimes both on the same top, and there is no relationship with more or less stiffness. I also have a fair amount of Euro spruce that is very fine grain and relatively weak. It's an aesthetic thing. Personally I find wide grain to be pleasing to the eye and much easier to join "invisibly" (between 2 grain lines).

It is of course a matter of personal opinion, but the tone I seek is not between "weak enough" and "strong enough". Building a guitar on the cusp of disaster, as a few builders philosophise, is not entirely comprehensible to me.
It is relatively easy to make a guitar that doesn't fall apart, and just as easy to make one that folds within the first months of use. Finding the limit of either is a little more difficult to achieve, but not impossible after a few builds. For me, tone lies somewhere else.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

For quality of sound I like Adi with Lutz running a close second.Although visually the quality of Shane`s Lutz in my opinion is much higher.So as Hesh said it`s pretty hard to beat Lutz for consistent quality in sound and beauty.
James

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James W Bolan
Nashville Tennessee

'Stiffness'

Ya gotta love it: everybody using a term in ways that seem to have three different meanings (or so) and nobody defining what they mean.

Stiffness, properly so called, is a product of the Young's modulus (E) of the material and the size and shape of the section of the piece. If you talk about a rectangular beam, the stiffness will be 1/12*E*W*(H^3), where W is the width and H is the height, or thickness, of the beam.

The E value of wood tends to be highest along the axis of the trunk, called the 'L' or 'longitududinal' direction. It will be lower along the radius (R) and usually a bit lower than that perpendicular to the R direction, called the 'tangential' or T direction. This is basically due to the orientation of the cells of the wood; mostly along the axis, some along the radius (medullary rays), and none along the tangent.

So, for a given size beam, the stiffness will be highest if it's cut longitudinally, much lower (anywhere from about 1/2 to 1/10 or so) cut along the radius, and a bit lower on the T cut.

As has been said, any cut between pure R and pure T is much lower in E value across the grain. At a 45 degree skew cut the E value can be as low as 1% of what it is in the L direction.

I've been testing the wood I get in for the past several years, using a vibration test rather than deflection, but getting the same kinds of data. For _all_ softwoods, density is a good indicator of E along the grain (L). What's most interesting is that _all_ of the softwoods I've tested fall on the same line: a piece of Red spruce with a density of 400 kg/cubic meter will tend to have the same lengthwise E value as a piece of Western Red cedar: in fact, I have just such a pair of tops in my stash.

The 'normal' range of densities will tend to be different for different species. Usually WRC is one of the least dense woods, Engelmann next, and so on, up to Red spruce and Sitka. However, I have Engelmann tops that are among the least dense, and some among the densest, of all the tops I have. All wood species vary _a lot_ in density. The only way to know is to measure.

There is, as far as I can see, little correlation between the E value across the grain and anything _except_ the annual ring angle on the end grain.

Runnout does decrease the E value in the longitudinal direction. 'Bearclaw' is localized runnout, and has the expected effect. It does, however, seem to increase the E value in the radial direction a bit.

At least some of the things that give tops of a given species their character have to do with other measureable properties, like damping. I'd guess that _all_ of the things that make one speceis of wood 'better' for a certain use than others relate to measureable properties, but we may not know just yet what to measure. That's something we need to sort out.

I believe that any guitar top has to have a certain stiffness along the grain, and that, in most cases, 'lighter is better'. For this reason I tend to prefer tops that have low density, and relatively high E value along the grain for wood of that density. There are exceptions. Higher density does seem to give more 'headroom', all else equal, so if I'm making somethnig that will be played harf with a flat pick, I go for higher density. Classical guitars reallt apreciate the lower densities, and also low damping, which is why they work well with WRC, but low damping with higher density, such a Redwood, can be good too.

Cross grain E value, for me, has more to do with how easily I'm going to be able to get it to 'tune' than anything else. If I've got a top that's a bit 'floppy', I'll just save it for a narrower guitar, and find something 'stiffer' for the Jumbo. Some tops are, of course, beyond hope.

Like it or not, you do have to pay attention to cosmetics if you want to sell guitars. The customers expect a reasonably high grain count, even though that has little effect on anything, so you have to look at that. Straight grain and even color are usually high on the grading chart, but I've had really 'high grade' and expensive tops that were acoustically and structurally disasters. The grading standards do reflect reality to some extent: they don't downgrade wide grain or uneven color so much on Red spruce, for example.

I heard from someone awhile back that tops with a narrower/tighter grain pattern take longer to " break in " or loosen up. it would be interesting to hear a coment on this from some builders that have been building for a long time . Jody

I think you can probably put "Tighter grain takes longer to open up" along side of the "Tighter Grain is Stiffer" wisdom...

My guess would be more along the lines of...
"Dense" tops that have the same Thickness as "Soft" tops on the same factory guitar take longer to loosen up.... Eg. Comparing a Dense, Hard Red spruce top vs a Soft Englemann top... both at the same thickness on the same body/bracing/etc... (Say on otherwise similar Martin D-18s..) The lighter, softer top would probably "Open up" faster...

Thanks

John

There's massive variation between individual pieces of wood; the most valuable learning experiences in that respect were the two trips (so far!) to Rivolta in Italy, where I got to sift through piles and piles (I must have handled several hundred tops each time, at least 300 each time, I guesstimate).

My 'quick selection' was based on stiffness (everything cut to uniform thickness), and there was huge variation there, and no correlation with looks (grain count, regularity, etc.). There also wasn't a clear correlation between weight and stiffness; some of the densest stuff was really stiff, but some lighter weight stuff was equally stiff. There were less floppy tops among the denser material, but ended up mostly selecting relatively light weight (light to middle of the spectrum) tops that were at the stiff to very stiff end of the spectrum, leaving the very-stiff-but-heavy tops alone. I weighed a couple initially, but you get a very good feel for the relative weight of a piece of wood pretty quickly.

My favourite spruce is Lutz with a tight grain and a light consistent colour and High Mountain ToneWood delivers. It really comes down to me either taking the time to go through a wood pile or trusting someone else to do it for me. To date I have yet to even come close to finding in the wood pile the quality of wood Shane sends me.

Having a supply of wood that is consistently very close in quality and characteristics can also be beneficial when experimenting with those other elements of guitar building. When at all possible buy in bulk it saves $$$ in the long run.

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Michael Lloyd

“I was born to ignorance, yes, and lesser poverties ...
I was born to privilege that I did not see ... I didn’t know it, but my way was paved” – John Gorka