Dwight Brown

Grain Width on Spruce Tops

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All the posts on spruce have really got my pea brain going.  I have a couple of projects that are in process that relate to some of my violin and viola posts I have made lately.  When those guys are ready I am sure they will share with everyone.  I think the projects will be fun for everyone and I know I will enjoy the results.

 

My question for the assembled congress of luthiery is this:  Does the grain width of the spruce for the top of an instrument matter?  I have always been fond of medium to wide grain for a top.  I know that many makers, especially earlier ones?, liked very fine grain spruce.  Is this anything that matters or is it just visual?  I have found the playing properties of fine grained spruce to be stiffer and less responsive, this without any real basis at all.   I have a feeling it is all in my head.

 

 

 

Dwight

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Ok, here goes;

I like thin grained Sitka.

I like the quartering to be as near perfect as possible, and I like the billet to be split and not sawn if possible.  I have a large enough band saw to work a rough billet, easily enough.

I like the wood heavy, in weight, and aged for at least twenty years. 

I prefer to work my front plates a bit thin, and heavier dense wood goes generally better with such thinning.

I also like highly (as in high numbers) grained bass bars.

I have some Sitka bass bars hanging around, that have somewhere around thirty-forty grains/inch. 

Sound posts - the same.

 

That said, I've seen and played wide grained tops, that I also have liked a great deal - so, I am supposing that it's simply what you do with what you have, and I have simply designed around what I like.

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A common pattern seen is the top plate grain is narrow in the middle and widening toward the sides.  Would narrow grained spruce be stiffer than wide grained?  I imagine that  within more or less normal grain types the skill of the maker trumps wide versus narrow grain.

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Would narrow grained spruce be stiffer than wide grain?   95% of the time, yes.   You may find elsewhere on Maestronet where I mentioned I started making tops last summer.  I had two tops- 1 with wider grain. the other with tight grain.   It didn't take long to make weight and hz preference with the wider grain.  Actually, I had to be careful of going to low- there for a bit I was on the top left upside of the platetuning.org graph for plate compatibility.   The tight grain top- a totally different story.   Oh, an acceptable weight barely but it took forever to get that piece down to a prefered hz level.  These were 2 totally different instances  that I thought would of had similiar or like results.   Only good thing to look foward to is when both are assembled and finished, I'll have a good way to compare what I actually did  over the summer.  The other 4 violins I made with these 2 fall in the middle of these 2 hz wise but the weight vary.

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 Would narrow grained spruce be stiffer than wide grained?

You can't count on it. I've run across loads of exceptions.

I like to choose grain which is wide enough that it's clearly visible from a normal viewing distance, rather than blurring together.

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Not making a point, just an observation. I have a bass in the shop for repair and it has very unusual grain on the top. The grain width is medium width down the center joint (14-15 per inch), widening slightly, then a abrupt change to VERY narrow width grain (23 per inch) and then widening to 5 grains per inch in the lower flanks. This is a two-piece top with no added wings. Both sides are mirror images of each other. The bass was made in Cremona, 1976 by Luciano Bini.

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Since I am the one who likes to quantify stuff I guess I should have looked to see if there is a standard measurement .  I guess average spacing in millimeters or winter lines per inch or centimeter , or something like that.  Mr. Burgess has exactly the sort I have in mind as fine grained where the lines are so close together that they seem to blur at a normal viewing distance.

 

 

DLB

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I have not noticed any trend in the measurable properties associated with grain width.  However, there might be a negative effect on speed of sound if the winter growth is a higher percentage of the total (just one or two qualitative observations).

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Not making a point, just an observation. I have a bass in the shop for repair and it has very unusual grain on the top. The grain width is medium width down the center joint (14-15 per inch), widening slightly, then a abrupt change to VERY narrow width grain (23 per inch) and then widening to 5 grains per inch in the lower flanks. This is a two-piece top with no added wings. Both sides are mirror images of each other. The bass was made in Cremona, 1976 by Luciano Bini.

 

Maybe you are looking at it the wrong way..

You have 5 rings /inch at he flanks, gradually narrowing to a very narrow, slow growth of 23 rings/inch, then abruptly widening again followed by a narrowing of the rings slightly towards the centre joint..

 

That can happen (abrupt change from very narrow to wide) when several mature trees around the one in question are chopped down at the same time, resulting in more sunlight, nutrients etc.. for the remaining ones, accelerating  ring-growth.  

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Mirecourt violins tend to have wider grain tops than say Roths of the same period. So do Bretons.

A few violins from the Becker shop I have seen had wider grain than average. Including a Carl Becker.

 

Just my very limited experience.

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From my experience grain spacing in spruce has absolutely nothing to do with stiffness. The stiffest piece of spruce I've handled has a grain spacing of over 1/8", and was used as packing material for some guitar tops I purchased. I've had some tops that had 30 to 40" grain lines per inch that were too floppy to use. Guitar tops are thinner, of course, and are much easier to flex.. 

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With the discussions on sitka and engelmann spruce, and grain spacing, I pulled out one of my sitka tops, smoothed it out, and counted grain lines.  Very surprised to see the narrow spaced side approaching 50 lines per inch.  In the photo, the scale is metric.

 

post-76933-0-35874200-1425316786_thumb.jpg

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With the discussions on sitka and engelmann spruce, and grain spacing, I pulled out one of my sitka tops, smoothed it out, and counted grain lines.  Very surprised to see the narrow spaced side approaching 50 lines per inch.  In the photo, the scale is metric.

 

attachicon.gifSitka.JPG

 

Nice!

Yes, it's somewhat easy to get tightly grained Sitka...

Many of the trees used for tonewood, are very old, very wide trees.

 

I read through your blogspot.

Very interesting .

I lived in the Manhattan Beach area, for a lot of years. Does the Easy Reader newspaper still exist? (Or the Beach Reporter?) I used to be the art director for them (the Easy Reader) when they were located over the old theatre, right there on the strand... in Hermosa - oh the memories!

I love the beach area there in the south bay, in fact, during High School days I was a local surfer. 

Back then, there were no surfer gangs, and anyone could surf anywhere, any time, from Palos Verdes, clear to Malibu.

I hear that things have changed.

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I lived in the Manhattan Beach area, for a lot of years. Does the Easy Reader newspaper still exist? (Or the Beach Reporter?) I used to be the art director for them (the Easy Reader) when they were located over the old theatre, right there on the strand... in Hermosa - oh the memories!

I love the beach area there in the south bay, in fact, during High School days I was a local surfer. 

Back then, there were no surfer gangs, and anyone could surf anywhere, any time, from Palos Verdes, clear to Malibu.

I hear that things have changed.

 

  I live in northern San Diego county, Craig, just to the east of Camp Pendletown.  Far from the LA beach scene.  Not much going on around here (hence the blog).  Definitely no surfer gangs.  The beach is about a 20 mile drive.  Probably more activity in Roswell!  :)

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This is probably a silly question, but would you want a wider grain on a larger instrument (viola or cello)? Practically speaking, the size of a cello or bass probably necessitates wider grained piece of wood, but I am speaking of tone here.

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This is probably a silly question, but would you want a wider grain on a larger instrument (viola or cello)? Practically speaking, the size of a cello or bass probably necessitates wider grained piece of wood, but I am speaking of tone here.

 

Not silly at all.  Many famous names in the field say that's exactly right.  But it's probably really contingent on how the thing is arched and lots of other considerations too, although in general, that's the word.  Wide grains in the top for more beautiful lower registers.

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Wider grains  often occur on wider instuments like basses and Celli because trees big enough to provide 2 piece fronts for them were generally found at lower ( but still high) altitudes. Quite often celli or bass that have narrow grain fronts have 4 or 6 piece fronts and sound fine.and beautiful in lower registers

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In conifers, such as spruce, there's a correlation between grain width (growth rate) and density. Faster growing trees increase the lower-density early wood and so have a lower overall density, Slower growing trees have a higher proportion of the denser late wood and so have a higher overall density. In extreme cases (such as the long-leaf pine growing in low-nutrient conditions on the Florida Keys) the slow growth can create wood nearly as dense as lignum vitae.

 

Denser wood tends to be stiffer overall, but not always in a uniform way because other factors come into play -- so samples can vary a lot. 

 

For hardwoods such as maple, the growth rate/density correlation is more complex so the same relationship does not apply. 

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Melvin: That makes sense. A lot of people say that is what happens to sound best, but that happens to be how it must be done too maybe, barring the solution you mention. Can you post a photo of a cello front in 6 pieces? I would like to see one. I know wings aren't that uncommon (although modern makers are afraid of them) but I haven't seen 6 piece fronts. Or is this done more in basses? Interesting. Tia

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On 3/1/2015 at 11:20 PM, Dwight Brown said:

All the posts on spruce have really got my pea brain going.  I have a couple of projects that are in process that relate to some of my violin and viola posts I have made lately.  When those guys are ready I am sure they will share with everyone.  I think the projects will be fun for everyone and I know I will enjoy the results.

 

My question for the assembled congress of luthiery is this:  Does the grain width of the spruce for the top of an instrument matter?  I have always been fond of medium to wide grain for a top.  I know that many makers, especially earlier ones?, liked very fine grain spruce.  Is this anything that matters or is it just visual?  I have found the playing properties of fine grained spruce to be stiffer and less responsive, this without any real basis at all.   I have a feeling it is all in my head.

 

 

 

Dwight

Dwight, you may want to read this: http://pacificrimtonewoods.com/wp-content/uploads/SitkaSpruceReport.pdf. In it I learned that the ATR (ability to resonate) rating goes up as the number of rings per inch go down. They measured down to 7 rings per inch I think and as high as 35 (going by memory). 

So coarse grain yields higher ATR. Makes sense... fine grain has more latewood volume, which is heavier / denser and requires more energy to move. So fine grain can negatively impact your weight/stiffness ratio. It's an aesthetic concern at best, a mistake at worst (if people take fine grain as gospel without considering the science of acoustics).

Conclusion: use what you like!

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While Cremona makers certainly did sometimes use fine grained spruce, I think you can fairly claim that they mostly steered toward medium wide and very straight grained spruce.

This also seems like a contrast to some other traditions.  

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In handling  many 1000's of guitar tops (where flexing is practicable), I came to the conclusion that grain spacing does not necessary correlate with  lateral (cross-grain) stiffness.  Longitudinal stiffness isn't so easy to assess, and perhaps there is some correlation - or effect?

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