Acoustic guitar without humidifier in case

[Wayne27]

How long can an acoustic guitar survive in its case if it didn’t have a humidifier?

[eclecticsynergy]

Has the guitar in question already languished, or is it a case of you having to leave one unattended for a while?
How long a period are we talking about? And where? A lot depends on the immediate environment where it's left.

Sitting in a basement is one thing. Baking in an attic or garage or storage unit is a lot more harsh.
Air conditioning indoors keeps temps reasonable but tends to make the air very dry.

If you can't count on a controlled environment, a few things can be done to help forestall damage.
Make sure the guitar and its case are thoroughly humidified for a week or two in advance.
You can slow moisture loss by wrapping the case in plastic film, then sealing it inside a double layer of heavy trash bags.

Needless to say, always loosen the strings if it's being stored for longer than a month or so.

Some guitars are more prone to damage than others too.
Ebony in particular shrinks quite a bit more than most other woods when it becomes dessicated.

[Mincer]

Here in Florida, forever. It is near 100% humidity inside or outside, all the time.

[alex1fly]

My first acoustic, a $100 Fender from the year 2000, has spent precisely zero minutes in a case or with a humidifier. No issues related to humidity. Never was a great guitar so I'm comfortable letting it dry out. Mostly it lived in Oklahoma, a humid state, and then the last few years in Colorado, a dry state.

My second acoustic, a $150 Stratacoustic from the year 2009, is the same.

Come to think of it, I simply don't keep stringed instrument in cases. Wind instruments, yes, as the pads dry out. But guitars and basses, nah. It's your call though. If you'd be heartbroken if it become unuseable and unrepairable, I guess try to control the humidity somewhat.

[jeremy]

well, im gonna saw a long damn time. i have a '64 or so hofner j45 copy that is in a chipboard case that, as far as i know, has never had a humidifier near it and its still in one piece. good idea? dunno but there it is

[PFDarkside]

Laminate guitars don’t really need it (although it’s obviously beneficial). I guess solid top/back/sides depends on the construction and environment.

[JB_From_Hell]

Consult the manufacturer of your guitar, then get a hygrometer for your house. Compare the data and see if you need one.

My dad had a humidifier in his house where all his instruments were on hangers. They’ve been at my house now, with no humidifier for over a year, and no change to them.

[GuitarStv]

I've strummed a great sounding and playing 70 year old solid wood guitar that was never humidified and spent it's whole life in Ontario (ranges well up past 90% humidity in the summer, and well below 20% humidity in the winter).

It's probably a good idea to try to keep your instrument in ideal ranges, but I would have no real concerns with leaving those ideal ranges on a regular basis. Guitar humidifiers and dehumidifiers didn't exist in the 20s, 30s, 40s, 50s, 60s, etc. but a huge number of people were playing guitars just fine. Many of the concerns regarding humidity and acoustics seem overblown.