Are some Tonewoods Less Sensitive to Humidity?

[Dr356]

Its a pleasant 9% humidity this morning in Southern Arizona....Are there some tonewoods that are not as sensitive to low/high humidity than others?

[Guilty Spark]

https://www.acousticguitarforum.com/...d.php?t=249272

https://www.acousticguitarforum.com/...d.php?t=564823

[charles Tauber]

Originally Posted by Dr356

Its a pleasant 9% humidity this morning in Southern Arizona....Are there some tonewoods that are not as sensitive to low/high humidity than others?

short answer: yes, but for all practical purposes, at 9% RH, the minor differences in wood species won't make any difference in the care you'll need to provide.

[Pura Vida]

Also, keep in mind that RH% inside your home is more important than outside RH%. Are you monitoring the humidity inside your home with a decent hygrometer? You can use a humidifier (or less likely, dehumidifier) to help pull up the indoor RH%, as needed, into your optimal range.

[SkipII]

Tonewood is still a tree. Even after being (kiln- or air-) dried, it is still a living organism, one with a memory. Most of the great tone woods are from topical climates, which is what leads most experts to say that an RH of 45-55% is ideal for guitars. While the new approach of torrefying the wood to stabilize it and accelerate the sonic "patina" can mitigate against the wood's propensity to absorb (or discharge) moisture, the process has as much to do with the volatile elements in the wood (oils, sugars, etc.). A terrified guitar is not "humidity-proof."

If you're serious about your RH being 9% (and you mean inside, not just outside), I can't imagine a tonewood -- even one from an arid climate -- would tolerate that for long.

[Dr356]

The outside humidity can be very low at certain times of the year. Inside is a bit better, in my house, 40% or so and I have humidifiers in all the cases. There is a professional harpist just down the street and she installed a whole house humidification system.

[Goodallboy]

Originally Posted by Dr356

Its a pleasant 9% humidity this morning in Southern Arizona....Are there some tonewoods that are not as sensitive to low/high humidity than others?

No, just some guitarists.

[zmf]

Originally Posted by SkipII

Most of the great tone woods are from topical climates, which is what leads most experts to say that an RH of 45-55% is ideal for guitars.

Just curious about this statement.
True, some tonewood grew in humid tropical climates, but is that more important that the ambient humidity at which the wood was dried, and the guitar built? In other words, will rosewood timber dried, stacked and built in a country with high humidity be more of a problem if used in a drier country than one both built and played in a country with the same humidity?

I've read that 45-55% is ideal because most guitars, at least in the USA, were build at that RH.

[tadol]

Originally Posted by zmf

I've read that 45-55% is ideal because most guitars, at least in the USA, were build at that RH.

That is correct - middle of the range, as close as you can get to median if you can’t control where the guitar is going to get shipped. Where the wood is from has no bearing on it.

[charles Tauber]

Originally Posted by SkipII

Most of the great tone woods are from topical climates, which is what leads most experts to say that an RH of 45-55% is ideal for guitars.

The climate in which a tree grew is irrelevant to properly dried wood. Most wood for fine woodworking purposes is dried to about 6 to 8% water content, regardless of where it grew.

Originally Posted by zmf

In other words, will rosewood timber dried, stacked and built in a country with high humidity be more of a problem if used in a drier country than one both built and played in a country with the same humidity?

I've read that 45-55% is ideal because most guitars, at least in the USA, were build at that RH.

Yes.

Guitars are more likely crack as they dry and shrink than they are when increasing moisture content and expanding. Guitar makers attempt to chose a humidity level that is a little below the middle of the range that a guitar is intended to live in. It is for that reason that most guitars made in North America are made in the 40% to 45% relative humidity range.

In some cases, small makers are willing to tailor the humidity at which they make an instrument to suit a particular climate.

[donlyn]

Are some Tonewoods Less Sensitive to Humidity?

While there have been many threads on humidity, I haven't seen too many focused on wood itself rather than the humidity. I have read the 2 previous threads mentioned in post #2 by Guilty Spark. Thanks for the extra info sources, by the way. Some responders have distanced laminates from this, which seems fair enough. So consider just solid wood guitars. Somehow the gut reaction is yes, of course.

While there may some who know or can calculate the exact effect by type of wood, I'm not one of them. But here's something a little different. I have a few guitars which are solid spruce topped rosewood. Most of them are large sized instruments. During the humid season, usually late summer here, the laminates seem to sound about the same, but the rosewood solids don't sound as consistent as their brethren. And the larger and more lightly built they are, the more off they can sound. Of course this may be just my hearing in the humid conditions, but the smallest rosewood, a Taylor Grand Concert about 15" across the lower bout, actually sounds pretty decent overall, even in high humidity. Say versus a Taylor Grand Orchestra. By the same manufacturer and with the same strings (Elixir PB HD Lights and both fingerpicked). My gut says the Grand Concert sounds more normal, that is, more true to its intended sound.

So I'm wondering if the size and build of the body can be a large factor in determining how much it can change and produce some irregular sounds as a result.

Just musing aloud.

Don
.

[Gordon Currie]

Originally Posted by Dr356

Its a pleasant 9% humidity this morning in Southern Arizona....Are there some tonewoods that are not as sensitive to low/high humidity than others?

For Arizona, the only 'tonewood' suitable for that climate is carbon fiber.

If you must have wood, consider laminated. It is much less sensitive than solid wood.

[mercy]

If you have 40 in your house it doesnt matter if there was, and there is, a tonewood that is less sensitive to change and splitting. Just keep it at 40

[The Bard Rocks]

Yes, there is a difference between various tonewood and how they react to humidity changes. But this, to my knowledge, has not been studied. And I have run across very little anecdotal evidence (opinion). However more than once I have been told that POC* is one of the woods least affected by humidity changes.



* Port Orford Cedar (which, despite the name, is a cypress, not a cedar)

[charles Tauber]

Originally Posted by The Bard Rocks

Yes, there is a difference between various tonewood and how they react to humidity changes. But this, to my knowledge, has not been studied.

The relative amounts by which various species of wood change size and shape has been extensively studied and tabulated.

Here are a few sources on the web. There are many more:

http://www.woodworkdetails.com/knowledge/wood/movement

https://www.thisiscarpentry.com/2010...wood-movement/

http://www.workshoppages.com/WS/Arti...ent-Charts.pdf