taylor 324 - higher humidity lowered the action ?

sublro · #1 08-20-2018, 06:38 PM

hey all - just wondering, i've always kept the house at very reasonable humidity but have had a busted central a/c for the last month with the way high humidity in the boston area. my 324 is pretty buzzy now. just a little relief on the neck, could up it a bit, but i'm kinda mystified why the action seems to have sunk a bit when the humidity's really been substantially up... always thought it goes the other way i.e. wetter guitar=swollen soundboard=higher action....

jazzguy · #2 08-21-2018, 04:43 AM

This is an interesting one. That has been my understanding (and experience) as well. Let's see what some of the Luthier experts say.

Wuchak · #3 08-21-2018, 06:55 AM

The higher humidity in the neck causes it to flatten which reduces string height. Picture the entire neck as a series of cells. If those cells are empty they deform and compress under string tension. If you fill them with water, which does not compress, they hold their shape under tension. A slight tweak of the truss rod should make things right again.

Mystery123 · #4 08-21-2018, 07:34 AM

Yes, also makes the notes sharp when wood expands or the other way but you have to retune.

beninma · #5 08-21-2018, 07:58 AM

Yah this has happened to me.

I have a dehumidifier now to compensate when the A/C isn't enough. Also Humidipaks.

I kind of wonder if this is something that happens when there is a mild overhumidification, the neck shifts first. If you continue to leave the guitar in a super high humidity environment then the top will start to belly up and raise the action but at first you see the neck move because we're more sensitive to relief?

jazzguy · #6 08-21-2018, 07:59 AM

Quote:

Originally Posted by Wuchak

The higher humidity in the neck causes it to flatten which reduces string height. Picture the entire neck as a series of cells. If those cells are empty they deform and compress under string tension. If you fill them with water, which does not compress, they hold their shape under tension. A slight tweak of the truss rod should make things right again.

Ah - this makes sense! thanks

Dru Edwards · #7 08-21-2018, 11:24 AM

Get a hygrometer to measure the humidity in the room where you keep your guitar. Low action can be a symptom of a dry guitar. Not sure if that's what you're seeing because based on your situation it seems like you should be experiencing the opposite (high humidity outside and no A/C inside)

Taylor's Symptom of a Dry Guitar article (low action):
https://www.taylorguitars.com/suppor...oms-dry-guitar

Taylor's Symptom of a Wet Guitar article (high action):
https://www.taylorguitars.com/suppor...oms-wet-guitar

jwing · #8 08-21-2018, 11:34 AM

Most of the neck has a waterproof finish, the top is sealed by an ebony fingerboard, and there is a steel truss rod embedded in the neck. How do you suppose the neck gains enough moisture to make it warp?

Wuchak · #9 08-21-2018, 07:29 PM

Quote:

Originally Posted by jwing

Most of the neck has a waterproof finish, the top is sealed by an ebony fingerboard, and there is a steel truss rod embedded in the neck. How do you suppose the neck gains enough moisture to make it warp?

Necks gain and lose moisture readily. You can feel fret ends projecting when they get dry and then have them disappear again when they rehydrate. If they get too dry, they won't return to their full original size and the fret ends need to be filed down.

birdsong · #10 08-21-2018, 08:33 PM

there are a number of articles online, authored by luthiers, that further explain what Wuchak has described. Some also touch on the "belly up" result that is mentioned by beninma. I realize the perils of the Internet but take a further look......

In the end, they report that higher humidity exposure will result in buzzing/lower action. I can't find authors who quite agree with the Taylor articles. So far what I find matches what Wuchak and beninma report here. Another rabbit hole I will have to keep exploring........

jwing · #11 08-22-2018, 08:00 AM

Quote:

Originally Posted by Wuchak

Necks gain and lose moisture readily. You can feel fret ends projecting when they get dry and then have them disappear again when they rehydrate. If they get too dry, they won't return to their full original size and the fret ends need to be filed down.

That would be the fingerboard. Are you suggesting that the fingerboard's shrinking width-wise by a millimeter or two will cause the neck and the truss rod to bend in a perpendicular direction?

bostosh · #12 08-22-2018, 08:18 AM

Get a micrometer from the tool box and measure rather than guess.
Hard to believe shrinking by millimeters.

sublro · #13 08-22-2018, 03:38 PM

Quote:

Originally Posted by Wuchak

The higher humidity in the neck causes it to flatten which reduces string height. Picture the entire neck as a series of cells. If those cells are empty they deform and compress under string tension. If you fill them with water, which does not compress, they hold their shape under tension. A slight tweak of the truss rod should make things right again.

this sounds right to me, as I did notice that there was almost literally no relief on the neck, which is indeed less than usual. a 1/8 turn has given me just a little bit of clearance and almost completely relieved the buzz except for heavy strumming.

so my money is on a neck with increased moisture having flattened out. Yet more nuances and complexities to be aware of in the care and feeding of solid wood guitars. Love this forum!