I’m hoping someone here can explain something that I haven’t been able to find a satisfying answer to - why don’t traditional acoustic guitars crack? I mean obviously sometimes they do, but it seems to me like that should happen all the time. For anyone unfamiliar, the front (top) and backs of wood acoustic guitars have their grain direction running parallel to the neck. And inside, there is bracing. That bracing runs perpendicular to the grain of the top, and the bracing is typically glued to the top. Gluing perpendicular grain is generally considered a huge problem when it’s an item of furniture and it would be reasonable to expect an object constructed like that to tear itself apart in a few years as humidity fluctuations do their thing. But guitars usually don’t do that and I don’t understand why.
Well if you subject your guitar to humidity fluctuations, it may well crack. Many do. My guild had a crack when I bought it, and when I moved to colorado it developed another. I have another guitar that has survived lots of changes in humidity and severe dryness without cracking. Maybe the wood was cured better, or I just got lucky.
I keep my nice martin humidified to ~47% all the time. Maybe it would survive dryness, but I don’t want to take the chance. When they dry out it changes the way they play, being humidified properly helps keep the action consistent as well as protecting it against cracks.
Yeah I’m familiar with guitar humidors and things like that which are used to protect valuable guitars. And they make perfect sense.
But I’m thinking about just regular parlor guitars, instruments that sit out in relatively uncontrolled environments and are played regularly, and instruments that are used on tours. Those instruments are subject to all kinds of chaos, and it seems like they should all be self destructing. And yeah, some do. But most don’t. And I think that’s really weird
Well-cured wood can help. Guitars built with green wood will crack easily.
Plywood guitars are tough - my resonator guitars are impervious to dryness, and they’re made of plywood basically.
The other thing that might explain it is survivor’s bias - the guitars on the wall at the pub or in a mountain cabin either survive, or they crack and die. We see the ones that made it. Same thing with 200 year old parlor guitars - they are survivors.
I hadn’t considered survivorship bias or that my original assertion was wrong. Solid point.
https://www.classicalguitardelcamp.com/viewtopic.php?t=132051
I don’t know, but here’s a conversation between guitar fans about it. The wood has to be treated carefully or it will crack, I guess.
There’s some interesting information in here for sure. Some speculation about intentional allowances for some warping to occur, and information about how some tops are basically 3-ply plywood which is a bit more stable.
Every music store sells humidifiers because it is well known that if you don’t keep your acoustic wood instruments (not just guitars, violins, harps, pianos…) at a very consistent humidity year round they will crack. If you go looking for antique musical instruments you will see a lot of them with cracks. The ones that are not cracked are the ones where the owners have cared about humidity and temperature.
Because they’re made in wells.
