Guitar Gets Hot, And Strings Go Sharp?

Lee Baucum · Post by **Lee Baucum** » 28 Feb 2015 2:56 pm

We recently played at a private party, outside on a ranch, here in South Texas. We were setting up in the sun and the temp was in the high 80's. I set up my guitar first and then carted in my amp and other stuff. When I checked my tuning, the guitar had gone way sharp, about a quarter of a step. I loosened the strings and retuned. After we got the sound system set up, I checked my tuning and noticed that all the strings were sharp again. Perhaps the body was expanding, in the heat? I've never had that happen before. I moved my guitar inside a room and came back a few hours later. Temps had dropped and the guitar and tuning were stable. I've never had this happen before.

Jim Cohen · Post by **Jim Cohen** » 28 Feb 2015 3:03 pm

Yup, temperature goes up, body expands and stretches the strings tighter at both ends. Voila.

Lee Baucum · Post by **Lee Baucum** » 28 Feb 2015 3:10 pm

I guess you haven't much of that problem lately!

Jim Cohen · Post by **Jim Cohen** » 28 Feb 2015 3:14 pm

Nope. But I'm amazed, given where you live, that you're just noticing this now... !

Lee Baucum · Post by **Lee Baucum** » 28 Feb 2015 3:18 pm

That evening, temps dropped down to the frigid lower 70's, in mid February.

Don R Brown · Post by **Don R Brown** » 28 Feb 2015 3:40 pm

Rub it in, rub it in! Going down to -4 here tonight!

Brian Brgant · Post by **Brian Brgant** » 28 Feb 2015 4:42 pm

Hmmm. - 4. Can I come over? I could use a break from the cold up my way.

Funny about the guitar. My house temp varies a good bit and I couldn't understand why when my guitar was cold, the strings went flat? If the strings get cold and shrink shouldn't they go sharp? I came to same conclusion in the opposite direction. The mass of the guitar is the determining factor. It is when it shrinks or swells,not the strings, that the strings go sharp or flat. Or that is my take on it?

chris ivey · Post by **chris ivey** » 28 Feb 2015 4:46 pm

i know temperature changes things, but i can never remember which way.

Jim Cohen · Post by **Jim Cohen** » 28 Feb 2015 6:20 pm

It's really very simple. Wood expands when warmer and the bridge and the nut are attached to the wood so when it gets warmer they get pulled farther away from each other which means the string is being stretched more which in turn means it will get sharper. The opposite happens when it cools down.

Emmett Roch · Post by **Emmett Roch** » 28 Feb 2015 6:34 pm

My GFI goes sharp when it gets cold. The aluminum body is not going to affect the maple die board very much, so it's usually within just a few cents.

chris ivey · Post by **chris ivey** » 28 Feb 2015 7:26 pm

ok, i get it.
warms up (sharp)
cools down (flat)

Jim Cohen · Post by **Jim Cohen** » 28 Feb 2015 7:28 pm

Attaboy.

Lee Baucum · Post by **Lee Baucum** » 28 Feb 2015 9:01 pm

chris ivey wrote:ok, i get it.
warms up (sharp)
cools down (flat)

However....I have had situations where an a/c vent is blowing right on me. The a/c kicks in and the strings cool and go UP in pitch. Then the a/c cycles off and the strings warm up and go DOWN in pitch. That happens pretty quickly. I suspect it takes a little longer for a guitar body to heat up or cool down enough to change the pitch of the strings.

chris ivey · Post by **chris ivey** » 1 Mar 2015 12:47 am

chris ivey wrote:i know temperature changes things, but i can never remember which way.

maybe that's why i get confused.

Charlie McDonald · Post by **Charlie McDonald** » 1 Mar 2015 4:30 am

chris ivey wrote: warms up (sharp)
cools down (flat)

It's good to leave yourself little notes lying around.

A piano has one ton more wood than a guitar. The body doesn't move; the soundboard has to give.
If it gets humid, the pitch goes up.
If it gets cold, the pitch goes up.
How come they're almost always flat?

That's why I switched to pedal steel. A steel body without a soundboard should stay in tune.

Now I find out they're mostly not made of steel at all.
No wonder my bar plays sharp. I mean flat.

John De Maille · Post by **John De Maille** » 1 Mar 2015 10:02 am

I've always experienced that situation of going sharp, when, the steel warms up. I mentioned it here, a while back and was corrected, as if I was an idiot, by a well known poster here. Didn't want to get into a pissing contest, so, I let the reply go unanswered by me. But, I knew that I was right in my thoughts and let the know it all expound on what he knew. To each his own, I guess, misguided or not.

Don Chance · Post by **Don Chance** » 1 Mar 2015 1:49 pm

Emmett Roch wrote:My GFI goes sharp when it gets cold. The aluminum body is not going to affect the maple die board very much, so it's usually within just a few cents.

My BMI does the same.

David Spires · Post by **David Spires** » 1 Mar 2015 2:43 pm

It must have some basis in the design/construction of the guitar, because I have always experienced warmer/flat, colder/sharp, open and with pedal/knees too on my Carter, MSA, and Sierra.

Here's wishing I could always play at a nice, consistent 70'F!

David Spires

Norbert Dengler · Post by **Norbert Dengler** » 1 Mar 2015 11:42 pm

whatever it does...
you`ll have to tune it!

Kyd Brenner · Post by **Kyd Brenner** » 7 Mar 2015 11:51 am

Years ago when I was playing regular gigs always had this problem, primarily in winter when LeGrande would travel in trunk for up to an hour in very cold weather. My trick was to get set up very first thing, retune to a few cents flat on all the strings and drop an electric blanket on very low temp over the guitar before I helped set up sound. After about 15 minutes I'd retune, but usually everything had come up to very close to pitch. Take the blanket off and do one final minor adjustment right before starting when the guitar had stabilized at temp of whatever room we were in. Two big advantages - I was in good tune for start of gig, and the guys preferred that I be in good tune to having me help carry all the heavy stuff in!

Unfortunately I never devised a drop-on air conditioner to deal with hot outdoor gigs.