Wood, weather and composites

[Guitarplayer_PR]

Several questions here:

1. With a weather that goes up and down or viceversa, would you prefer an all-laminate (or partial laminate) or a composite guitar?
2. Are you still "snobby" enough to only have all-solid guitars regardless of fluctuations on the weather?
3. What would be the best combination (and by best I mean more stable) of woods for an all-solid guitar to withstand weather changes?

[Osage]

Where I live it's pretty humid in the summer and very dry in the winter. We heat with a wood stove which dries things out even more. All this means is that for about 4 months in the winter and maybe some in the summer, my guitars all live in their cases with humidifiers. There's no issue with taking them out and playing them as long as they go back in the case when I'm done.

That said, I have toyed with the idea of getting a carbon fiber guitar to keep in the living room in the winter but have never found one that I liked the sound of enough to make me buy it.

[Muddslide]

I don't think of it as "snobbish" to prefer solid wood guitars. It's just personal preference.

Personally I prefer laminates because they are less fussy and delicate, but there is a trade off to some degree with regards to sound.

I haven't played enough CF guitars to make a judgment there. I also can't afford one.

But to be honest I'd probably stick with inexpensive laminated wood guitars over CF because I just prefer the look and feel.

[Muddslide]

Originally Posted by Guitarplayer_PR

What would be the best combination (and by best I mean more stable) of woods for an all-solid guitar to withstand weather changes?

I would be curious to hear suggestions on this specifically from some of the more knowledgeable members here.

[jaymarsch]

I am not sure snobbishness has much to do with it. I am fortunate to live in a mild area that does not have long-term extreme weather conditions so no need to not enjoy all solid wood guitars. I know plenty of players who also enjoy their all solid wood guitars and have no issue with the small amount of vigilance that it takes to care for them in more extreme weather changes. Obviously, laminated and CF guitars are there for folks who prefer them. I don’t think that it needs to be an either/or situation.
It is whatever you are more comfortable with.

If I lived in extreme weather, I would probably own a Rainsong or Emerald rather than a laminate but would keep my all wood guitars and just protect them the best I could.

It is good that there are so many good choices these days.

Best,
Jayne

[hermithollow]

"What would be the best combination (and by best I mean more stable) of woods for an all-solid guitar to withstand weather changes?"

"I would be curious to hear suggestions on this specifically from some of the more knowledgeable members here."

Mahogany back and sides and neck with a western red cedar top would be a relatively stable construction. All mahogany might be even more so if you are inclined that way.

[Guitarplayer_PR]

Personal experience:


A couple of days ago, I was teaching guitar at an academy. The classroom got way cold and my guitar at that class (Taylor DN3, sapele) sounded like CRAP!!!!!!!! Once I got home and the guitar warmed up, it started to sound great again. I knew my DN3 was sensible to weather, but not that much.

On the other hand, my Taylor 414CE (ovangkol) seems to have more resistance to weather changes than the DN3. And my GS Mini Koa laughs at the weather!

[BT55]

I live in NY and in the winter humidification is required for wood guitars. I have a whole house humidifier plus two automatic units in my man cave. Daily filling the humidifiers is a pain but keeping the guitars in mint shape is my only concern. If I’m taking a guitar out and temperature or humidity is a problem I’ll bring a CF. They are not affected and have great sound.

[charles Tauber]

Originally Posted by Guitarplayer_PR

What would be the best combination (and by best I mean more stable) of woods for an all-solid guitar to withstand weather changes?

A short answer:

Wood is an "anisotropic" material, which simply means that it has different properties in different orientations of its fibres/cell structure. One of the properties that changes with direction is how much the material expands or contracts in response to environmental humidity. The amount that it does so depends upon the species of wood AND how the fibres/grain are oriented in the piece of wood.

For many common woods, there are charts of experimental data for the amount that various species of wood expand and contract in response to changes in environmental humidity. The charts include expansion tangentially (i.e. in the direction of the circumference of the tree) and radially (i.e. in the direction of the radius of the tree). (There is negligible expansion or contraction along the length of a board (i.e. along the direction of the height of the tree).

Depending upon the species of wood, there can be considerable variation between the radial and tangential values. One of the reasons for using quarter sawn (aka "vertical grain") wood is that for many common wood species for tops (e.g. spruces, western red cedar, fir, redwood...) the maximum expansion and contraction occurs in the thickness of the board - the tangential direction in quartered wood - rather than side to side - the radial direction in quartered wood. What is needed to resist splitting in a guitar top or back, for example, is to minimize the side to side expansion and contraction. Quartersawing wood, in many species, accomplishes that.

This site, http://www.woodbin.com/calcs/shrinkulator/, provides radial and tangential values for a wide variety of woods. Ideally, to increase "stability", one would like the smallest values as well as the smallest ratio of tangential to radial coefficients.

Sitka spruce, for example, has a value of 4.3 radial and 7.5 tangential, meaning it expands and contracts more in the tangential direction than in the radial direction. Practically, for example, if one has a 16" wide Sitka spruce top, one can estimate that a change of humidity from 60% to 20%, say, the top will shrink to 15.92" radially and 15.85" tangentially. Practically, that predicts that a quarter sawn top will shrink across its width by .08" (16" - 15.92") while a flat sawn top will shrink by .15" (16" - 15.85"), more than 1/8".

By contrast, red spruce has values of 3.8 and 7.8, for radial and tangential coefficients, respectively. That suggests that, on average, quartered red spruce will expand/contract less than Sitka spruce, for the same change in humidity. However, the ratio of tangential to radial coefficients is greater for red than Sitka spruce, suggesting, on average, that it is less "stable" than Sitka. Regardless, the difference in values isn't likely enough to make much difference in the care required of an instrument made from these woods.

There are many other factors that go into "stability" of a finished guitar, but the choice of wood species and how it is cut are two of those.

[Guitarplayer_PR]

Originally Posted by charles Tauber

A short answer:

Wood is an "anisotropic" material, which simply means that it has different properties in different orientations of its fibres/cell structure. One of the properties that changes with direction is how much the material expands or contracts in response to environmental humidity. The amount that it does so depends upon the species of wood AND how the fibres/grain are oriented in the piece of wood.

For many common woods, there are charts of experimental data for the amount that various species of wood expand and contract in response to changes in environmental humidity. The charts include expansion tangentially (i.e. in the direction of the circumference of the tree) and radially (i.e. in the direction of the radius of the tree). (There is negligible expansion or contraction along the length of a board (i.e. along the direction of the height of the tree).

Depending upon the species of wood, there can be considerable variation between the radial and tangential values. One of the reasons for using quarter sawn (aka "vertical grain") wood is that for many common wood species for tops (e.g. spruces, western red cedar, fir, redwood...) the maximum expansion and contraction occurs in the thickness of the board - the tangential direction in quartered wood - rather than side to side - the radial direction in quartered wood. What is needed to resist splitting in a guitar top or back, for example, is to minimize the side to side expansion and contraction. Quartersawing wood, in many species, accomplishes that.

This site, http://www.woodbin.com/calcs/shrinkulator/, provides radial and tangential values for a wide variety of woods. Ideally, to increase "stability", one would like the smallest values as well as the smallest ratio of tangential to radial coefficients.

Sitka spruce, for example, has a value of 4.3 radial and 7.5 tangential, meaning it expands and contracts more in the tangential direction than in the radial direction. Practically, for example, if one has a 16" wide Sitka spruce top, one can estimate that a change of humidity from 60% to 20%, say, the top will shrink to 15.92" radially and 15.85" tangentially. Practically, that predicts that a quarter sawn top will shrink across its width by .08" (16" - 15.92") while a flat sawn top will shrink by .15" (16" - 15.85"), more than 1/8".

By contrast, red spruce has values of 3.8 and 7.8, for radial and tangential coefficients, respectively. That suggests that, on average, quartered red spruce will expand/contract less than Sitka spruce, for the same change in humidity. However, the ratio of tangential to radial coefficients is greater for red than Sitka spruce, suggesting, on average, that it is less "stable" than Sitka. Regardless, the difference in values isn't likely enough to make much difference in the care required of an instrument made from these woods.

There are many other factors that go into "stability" of a finished guitar, but the choice of wood species and how it is cut are two of those.

Short and to the point

Being more serious, you kind of answered my point about my GS Mini and weather. When I looked up the T/R Ratio of Koa, it's just 1.1, so based on it, Koa would be a great wood if someone looks for a stable guitar regarding environmental changes.

[The Bard Rocks]

1) Composite
2) Yes
3)Port Orford Cedar/ ? There are several.

[Muddslide]

Originally Posted by Guitarplayer_PR

...based on it, Koa would be a great wood if someone looks for a stable guitar regarding environmental changes.

I do not mean to argue on this point. What I know of woods could fill a thimble.

But I will say that among the ukulele cognoscenti (I do not count myself among them) koa as a wood used for uke construction is considered by some to be prone to cracking.

I know there is a great deal of disagreement on this point so I certainly do not present it here as a truism.

I would also add that in many cases we are talking about 50-100 year old koa ukes (Kamakas for example) which were made in very humid Hawaii.

[Steve DeRosa]

My wife and I have a "his-&-hers" set of Rainsong 17" jumbos - JM1000 6-string and JM3000 12-string...

Once the strings settle in after restringing, I only need to tune them once every 3-4 weeks (literally) - try that with any other 12-string regardless of price/maker...

Humidification is a non-issue, and things won't start getting funny under hot stage lights or at an outdoor gig (as happened to our bass player at a recent show )...

With Martin Retro Monels on both guitars the metallic edginess that turns off many players to CF instruments is gone, the sound being similar to a Taylor GO or Jumbo but more "forward" and with more clarity - as the owner of four Taylors, I like to think of it as the sound Bob T. hears in his head but can't quite achieve with all-wood construction...

If consistent tone with a minimum of maintenance is of primary importance, I can't think of a better instrument for a tropical climate such as yours...

[Guitarplayer_PR]

Originally Posted by Muddslide

I do not mean to argue on this point. What I know of woods could fill a thimble.

But I will say that among the ukulele cognoscenti (I do not count myself among them) koa as a wood used for uke construction is considered by some to be prone to cracking.

I know there is a great deal of disagreement on this point so I certainly do not present it here as a truism.

I would also add that in many cases we are talking about 50-100 year old koa ukes (Kamakas for example) which were made in very humid Hawaii.

Assuming the point you bring about koa ukuleles being prone to cracking, is there any reason why that happens?

[Earl49]

Koa instruments are usually built in high humidity environments, then live their lives in much drier climates. And if cracks do happen, they are much more likely to occur in highly figured pieces of koa wood. Plainer grades are more consistent in their properties, but not as nice to look at. These are generalities of course, and not absolutes.

I've owned koa and mango ukulele in dry Alaskan winters, and never suffered any cracks, but I do take care of my instruments in terms of humidity and temperature. The Hawaiian builder of the mango wood ukulele was reluctant to sell it me when I lived in Alaska, fearing that it would crack and he would get blamed. But I assured him that with several Martin and Taylor guitars at home (without dryness-induced cracks) it would be OK. To this day, I don't have any cracks in any of my wood ukulele. BTW, a guitar is more likely to crack than a uke. A wider sound board can contract further as it dries, putting way more stress on the wood.