uke vs. low humidity

Wildjoy

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Trying to understand this correctly...

As I understand things, laminate ukes and solid wood soundboard/laminate body ukes are generally regarded as being more "hardy" and able to handle conditions if the humidity is lower than ideal. But, if you have any wood on the uke at all, isn't it needing proper humidity just as much as an all-wood uke?

I bought my HPL Enya in a desert country and it had fret sprout. All of the ukes there that I picked up did. I doubt they were kept properly humidified in the store. I know that fret sprout is not as serious as a cracked soundboard, but how is a solid top uke less fragile than an all wood uke? "I've got a soundboard crack, but at least it's not two cracks--soundboard and body"? Or does having a laminate body somehow help to stabilize the wood soundboard?

Help me wrap my mind around this!
 
It's all about the grain. Ukes are traditionally made from thin sections of solid wood with the grain running lengthwise. This gives really good strength and response to vibration. Shrinkage will occur between the lines of the grain, and can very easily cause longitudinal cracks.

Plywood is made from three (usually) very thin layers of wood; the outer two have the grain running lengthwise and the inner layer is arranged with the grain at ninety degrees. This gives a much higher resistance to cracking.

HPL is not the same as plywood. It also uses different layers of - erm - 'material' but contains a large amount of filler. It is more akin to fibreglass or the stuff from which kitchen worksurfaces are often made.

Not to disparage HPL ukes; I have several and the good ones can be very good indeed.
 
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Most solid woods tend to shrink in low humidity. If the luthier aged the wood in a high humidity environment, the shrinkage will likely begin sooner than a uke made of wood aged in a drier environment. If the entire uke is made of solid wood, then the shrinkage will be happening not only on the soundboard, but also the sides and back. That additional force will compromise the structural integrity of the instrument sooner than if the shrinkage is only occurring on the soundboard. (At least that’s how I understand it.)
 
It's all about the grain. Ukes are traditionally made from thin sections of solid wood with the grain running lengthwise. This gives really good strength and response to vibration. Shrinkage will occur between the lines of the grain, and can very easily cause longitudinal cracks.

Plywood is made from three (usually) very thin layers of wood; the outer two have the grain running lengthwise and the inner layer is arranged with the grain at ninety degrees. This gives a much higher resistance to cracking.
But if you have a solid top with a laminate body, wouldn't it need the same care as an all solid wood (not solid body) ukulele?
 
Any solid wood is affected by dry humidity and shrinks. The thinner the wood the faster it shrinks and as said above thinner wood doesn't have much room to shrink before something has to give. The "give" is typically between the grains, but it can also be the glue pulls loose. A solid wood top on a laminate body shrinks while the rest of the body stay pretty stable but it shrinks the same amount whether the body is solid or lam. But with an all solid wood body, everything is shrinking (at different rates because the side and back woods are thicker) and pulling in different directions so that amplifies the affects of the shrinking. But either way the solid wood top will shrink the same as will the fretboard.
 
Yes the wooden neck is often ignored in humidification advice even though single piece necks readily expand and shrink as humidity changes, resulting in loss of tuning and fret sprout. If you have a fairly tight case then a soundhole humidifier can also keep the neck humidfied. But if you have plastic or laminate body that does not need humidification with a wooden neck, then a separate source of moisture for the neck is often desirable.
 
Any solid wood is affected by dry humidity and shrinks. The thinner the wood the faster it shrinks and as said above thinner wood doesn't have much room to shrink before something has to give. The "give" is typically between the grains, but it can also be the glue pulls loose. A solid wood top on a laminate body shrinks while the rest of the body stay pretty stable but it shrinks the same amount whether the body is solid or lam. But with an all solid wood body, everything is shrinking (at different rates because the side and back woods are thicker) and pulling in different directions so that amplifies the affects of the shrinking. But either way the solid wood top will shrink the same as will the fretboard.
I agree that humidity is a bigger problem for the thinner woods that are generally used on higher quality ukuleles. Some cheaper "solid wood" ukuleles are just as thick as laminate ukuleles and less affected by humidity.
 
Trying to understand this correctly...

As I understand things, laminate ukes and solid wood soundboard/laminate body ukes are generally regarded as being more "hardy" and able to handle conditions if the humidity is lower than ideal. But, if you have any wood on the uke at all, isn't it needing proper humidity just as much as an all-wood uke?

I bought my HPL Enya in a desert country and it had fret sprout. All of the ukes there that I picked up did. I doubt they were kept properly humidified in the store. I know that fret sprout is not as serious as a cracked soundboard, but how is a solid top uke less fragile than an all wood uke? "I've got a soundboard crack, but at least it's not two cracks--soundboard and body"? Or does having a laminate body somehow help to stabilize the wood soundboard?

Help me wrap my mind around this!

I say, "Better safe than sorry." Wood is wood. I've seen plywood delaminate.
 
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