Stability

[eflatminor]

What are the most 'stable' tonewoods? I'm imaging a small body fingerstyle beauty that I will travel with, all times of the year, from desert Southwest to sub zero Midwest to humid Florida. What is least likely to move or heaven forbid, crack? Light weight would be nice too. What about soundboards?

I will of course, take humidity and temperature precautions, just as I currently do with my Goodall (no problems so far), but if I had a 12 fret 0 or 00, I would travel with it, so it might as well be up to the task.

[Cornerstone Guitars]

I would say that mahogany is probably the most stable wood. Actually, that is the reason it is primarily used for necks.

[warfrat73]

Port Orford and Alaskan Yellow Cedar are supposed to be about the most stable tops available.

[jeastman]

I believe there are at least a few of us who are still hoping Peter will crank out an all-mahogany beauty for Healdsburg...so maybe you can stick your name on that

[CraigRyder]

I wouldn't worry to much about it unless you are going to actually sit in the everglades or seashore for prolonged periods (days) and play.

If the guitar is built properly with wood that has been handled/dried properly it will stand up to your traveling. Especially if you take a few precautions.

Cheers,

[runamuck]

Quarter-Sawn Honduran Mahogany and Port Orford Cedar.

Jim McCarthy

[Tim McKnight]

Another vote for Mahogany and you can also throw Eastern Black Walnut into the mix as well. pair either with Adi and you will have a great little FS git.

[kwang]

+1 that mahogany is the most stable wood.

[tkuane]

At the risk of angering members of the forum (yet again!). Some of the previous comments cannot have no basis in their belief (in the context of most stable) and are simply not true. Consult this chart from wood flooring professionals, as they have plenty of experience with wood shrinkage, with very negative effects on their work. They spend much more time researching these kinds of things and know this aspect much better.



The full page is here: Hardness and Stability Chart

If you read the page, you find that some tropical woods are less reliable than the chart suggests, The simple reason, as we have said on this forum is that the woods used have not yet acclimatised (or dry-aged) to the average relative humidity of the climate where the wood was used. For example, if you take a tropical wood and take it far away from the equator without letting it dry age for a year or so, it would have a good chance of warping regardless of its stability. Dry aging and taking precautions with relatively humidity is all you need to do.

Also, the reason mahogany is used for necks, is because anything harder and heavier will result in a neck heavy guitar that puts more strain on the posture of the player. If stability was the only consideration (and price is not) neck would all be made of ebony or something of similar hardness and stablity.

PS. Unlike the embarrassing 'tone charts of various tonewoods', the above is actually *gasp* real data with real numbers.

[tkuane]

Back to the thread starter's concern. If you want something that will endure abuse and neglect, buy an inexpensive, overbuilt guitar. If you want your personal preference in tone, you'll have to pick a small range of woods that will give you the tone that you want, and live with the consequences of maintaining humidity and temperature (because these days, people can even crack and deform even the very 'toughly' built Taylor guitars.

The reason why I use the words abuse and neglect is because taking care of humidity is a simple thing to do if you care for your guitar. All you need is a case that is decent with temperature and moisture insulation (a case cover helps), a small digital hygrometer (I use a Caliber III), and in low relative humidity, a kettle (which you should be able to find everywhere you go) boiling away in the room with the lid off for a few minutes (hygrometer a few meters away from the kettle to let you know when to stop boiling). Turn on the air-conditioning or the heater if relative humidity is too high. None of these things are difficult things to do and can keep your guitar at perfect relative humidity every time you take it out to play.

[warfrat73]

I don't see a whole lot of tonewoods on that chart tkuane. Black Walnut is occasionally used, but not nearly as often as some of the other walnut varieties, White Oak has been used on a few hand built guitars lately. Wenge I suppose has been used occasionally. I'm not sure about "Hard Maple," that's presumably different than the Big Leaf maple (a relatively soft maple) which is what seems to be used most commonly in guitars. The only mahogany on there is "Santos" and I don't recall hearing of any guitars being made from that. Paduak seems to be picking up a bit of steam in the guitar world, that's on there.

I'm also not totally convinced that there's a 1:1 relationship between stability in flooring applications and guitar building. The website cited here even says "[t]he dimensional change coefficient can be used to calculate expected shrinkage or swelling. In actual practice, however, change would be diminished in a complete floor, as the boards' proximity to each other tends to restrain movement." If proximity restrains movement what do bracing and gluing do? There's also an asterisk next to a few wood types that provides the caveat that "Although some tropical woods such as Australian cypress, Brazilian cherry, merbau and wenge appear in this chart or have excellent moisture stability compared to domestic oak, actual installations of many of these woods have demonstrated significant movement in use. To avoid problems later, extra care should be taken to inform potential users of these tendencies prior to purchase." This provides pretty clear anecdotal evidence that real world applications do not necessarily follow laboratory findings.

[tkuane]

Well, if you actually read and understood my post, you'll find that I've explained the reason for the confusion.

You're completely at your own liberty to believe that wood has its own magical properties once they become part of a guitar. I on the other hand, chose to rely on carefully measured observations. Which are done by the Forest Products Laboratory, of US Department of Agriculture, no less, so I see no reason for your prejudices to dispute the source.

That's a very old chart (compiled not long after I was born), so if you want to know more about recent woods that were only available and given their english names in the last few years, you'll have to find a more up to date list. No doubt a new list by the same department will completely correlate with what I've said about tropical woods warping easier than expected. The reason why I am so sure is because everyone but a complete novice will not be aware of the importance of acclimatising the wood before working with it. As I said in my post earlier (again), this is due to woods not being aged properly before they were used.

The boards' proximity to each other restricts their movement, but not their cracking, so I don't see what you're getting at. That is an explanation into possible errors in their measurement of warping. In guitars, as in all other forms of wood working, shrinkage and warping are not the only issues with humidity in relation to the structural intergrity of wood. To be completely honest, I doubt your ability to follow this discussion at any reasonably informed level.

Good measurements and reliable research will always point out shortcomings and errors in their own work. That is what makes the published work good and dependable. However, people such as yourself use it instead as a form of critism against the authors, which point out nothing except your own incomplete grasp of the whole nature of sharing information. In this work, the inconsistencies in quality of dry-aging the wood is obvious to any wood-worker, due to the origins of the tropical wood. It would be unprofessional for the department that published this work to comment that the woods were inferior in one way or another, not least because these things are impossible to prove. However, as they rightly began by mentioning that these are tropical woods, it is naturally implied that dry-aging is a large factor. Again, the fact that this possibility did not immediately cross your mind proves your lack of knowledge in this matter.

Once again, you're completely free to believe that logic does not apply to tonewoods. Everyone is entitled to their opinion.

Originally Posted by warfrat73

I don't see a whole lot of tonewoods on that chart tkuane. Black Walnut is occasionally used, but not nearly as often as some of the other walnut varieties, White Oak has been used on a few hand built guitars lately. Wenge I suppose has been used occasionally. I'm not sure about "Hard Maple," that's presumably different than the Big Leaf maple (a relatively soft maple) which is what seems to be used most commonly in guitars. The only mahogany on there is "Santos" and I don't recall hearing of any guitars being made from that. Paduak seems to be picking up a bit of steam in the guitar world, that's on there.

I'm also not totally convinced that there's a 1:1 relationship between stability in flooring applications and guitar building. The website cited here even says "[t]he dimensional change coefficient can be used to calculate expected shrinkage or swelling. In actual practice, however, change would be diminished in a complete floor, as the boards' proximity to each other tends to restrain movement." If proximity restrains movement what do bracing and gluing do? There's also an asterisk next to a few wood types that provides the caveat that "Although some tropical woods such as Australian cypress, Brazilian cherry, merbau and wenge appear in this chart or have excellent moisture stability compared to domestic oak, actual installations of many of these woods have demonstrated significant movement in use. To avoid problems later, extra care should be taken to inform potential users of these tendencies prior to purchase." This provides pretty clear anecdotal evidence that real world applications do not necessarily follow laboratory findings.

[tkuane]

For those remaining who wish to prove me wrong, I point you towards the resources to do so.

Here it is:

Title: .Wood Handbook, Wood as an Engineering Material (All Chapters)
Publication: Forest Products Laboratory. Wood handbook - Wood as an engineering material. General Technical Report FPL-GTR-190. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory: 508 p. 2010
Author(s) Bergman, Richard; Cai, Zhiyong; Carll, Charlie G.; Clausen, Carol A.; Dietenberger, Mark A.; Falk, Robert H.; Frihart, Charles R.; Glass, Samuel V.; Hunt, Christopher G.; Ibach, Rebecca E.; Kretschmann, David E.; Rammer, Douglas R.; Ross, Robert J.; Star
Year: 2010


I trust the number and variety of woods included is sufficient for one even as demanding as warfrat.

[warfrat73]

Originally Posted by tkuane

Well, if you actually read and understood my post, you'll find that I've explained the reason for the confusion.

...be completely honest, I doubt your ability to follow this discussion at any reasonably informed level.

Wow.

Actually I did read and understand your post. The source that you cite here mentions not one word, not one, about drying, curing, preparation or cracking. So either you are privy to outside information or you are making an inference. Either way, that's not what that source says; I was responding merely to the source that you cited.

Secondly, the chart is ranked based on dimensional change coefficient, it says nothing, not one word, about propensity to crack.

Thirdly, if, as your source says, "the boards' proximity to each other tends to restrain movement" it is in no way a major leap to conjecture that a piece of wood that is constrained by a glue joint around its entire perimeter will also have restrained movement. It's certainly no more of a stretch than your assumption that the problem with the asterisked wood types is based on proper curing and not some other factor.

Fourthly, there's no reason, absolutely none, to attack me personally.

[tkuane]

Nice defence mechanism right there. I have to commend you. First you try to disprove what you do not completely understand, and now you try to shift attention to yourself as a victim of an attack. If you see an attack upon you personally in my post, it is your own creation. I only have issue with your own limited knowledge on this matter that wishes to create flawed conclusions (which will mislead others), nothing else. Go ahead, have a click on the link and have a good read. Remedy the source of our dispute.

Originally Posted by warfrat73

Wow.

Actually I did read and understand your post. The source that you cite here mentions not one word, not one, about drying, curing, preparation or cracking. So either you are privy to outside information or you are making an inference. Either way, that's not what that source says; I was responding merely to the source that you cited.

Secondly, the chart is ranked based on dimensional change coefficient, it says nothing, not one word, about propensity to crack.

Thirdly, if, as your source says, "the boards' proximity to each other tends to restrain movement" it is in no way a major leap to conjecture that a piece of wood that is constrained by a glue joint around its entire perimeter will also have restrained movement. It's certainly no more of a stretch than your assumption that the problem with the asterisked wood types is based on proper curing and not some other factor.

Fourthly, there's no reason, absolutely none, to attack me personally.