Can freezing cold/thawing snap a truss rod?

[carfish7]

Yup, it is snapped for sure. Question is, how?!?

I didn't do it. It sat outside in a car for 2 days while we went sub-zero. It was fine when I bought it, was subjected to the freeze, and now is definitely NOT ok!

Does anyone think a truss rod under tension might snap if deep-frozen? The guitar in question is a 1985 MIJ Squier Strat with a 24 3/4" scale. Damn shame as it was a cool as hell ride.

[crunchee]

Just curious, was this car parked out in the open and have good sun exposure during those 2 days? It wouldn't have made the car summertime hot, but it could have made the temperature inside the car go above freezing during the day, then down below again at night. That kind of temperature fluctuation wouldn't have helped, IMO.

[Bobby Marshall]

Murkat can fix it.

[Bloozguy]

A mild steel truss rod will expand and contract at a rate of 0.0000073 inches (7.3 millionths of an inch) per inch per degree Fahrenheit.

If the guitar was at 72 degrees Fahrenheit and cooled to -10 degrees Fahrenheit that would be an 82 degree change in temperature.

This would make the truss rod contract 0.0005986 inches per inch of length.

A 21-fret 24.75 inch scale guitar neck is will typically measure 17.39173228 inches from the nut to the 21^st fret.

That would make the total shrinkage of the truss rod 0.0104107 inches over its entire length.

I’m not certain what threads are used on MIJ Squier truss rod nuts, but they are likely M4 diameter x 0.7mm pitch or M5 diameter x 0.8mm pitch metric threads.

An M4 x 0.7mm truss rod nut will move 0.027559055 inches per revolution and an M5 x 0.8 mm pitch nut will move 0.031496063 inches per revolution.

That makes the 0.0104107 inches of truss rod shrinkage equal to 119 to 136 degrees of truss rod nut rotation or between 1/3 and 3/8 of a turn, depending upon the pitch of the truss rod nut.

The neck wood will shrink as well, but only about 0.0000017 to 0.0000027 inches per inch per degree Fahrenheit or a total of 0.0024244 to 0.0038505 inches over the length of the truss rod.

Easy answer…yep, could have snapped from the cold...and...

Murkat can fix it.

[Turdus]

Well.. after shipping a guitar UPS "Ground", and being told the headstock broke when the "Plane" hit a certain altitude... I would say anything is possible.

[carfish7]

A mild steel truss rod will expand and contract at a rate of 0.0000073 inches (7.3 millionths of an inch) per inch per degree Fahrenheit.

If the guitar was at 72 degrees Fahrenheit and cooled to -10 degrees Fahrenheit that would be an 82 degree change in temperature.

This would make the truss rod contract 0.0005986 inches per inch of length.

A 21-fret 24.75 inch scale guitar neck is will typically measure 17.39173228 inches from the nut to the 21^st fret.

That would make the total shrinkage of the truss rod 0.0104107 inches over its entire length.

I’m not certain what threads are used on MIJ Squier truss rod nuts, but they are likely M4 diameter x 0.7mm pitch or M5 diameter x 0.8mm pitch metric threads.

An M4 x 0.7mm truss rod nut will move 0.027559055 inches per revolution and an M5 x 0.8 mm pitch nut will move 0.031496063 inches per revolution.

That makes the 0.0104107 inches of truss rod shrinkage equal to 119 to 136 degrees of truss rod nut rotation or between 1/3 and 3/8 of a turn, depending upon the pitch of the truss rod nut.

The neck wood will shrink as well, but only about 0.0000017 to 0.0000027 inches per inch per degree Fahrenheit or a total of 0.0024244 to 0.0038505 inches over the length of the truss rod.

Easy answer…yep, could have snapped from the cold...and...

Murkat can fix it.

You just made all this up, didn't you?

Well, except for the last bit.........

[cynic]

Either that or he just gave the most dead-on-balls-accurate answer the internet has ever seen

[carfish7]

Either that or he just gave the most dead-on-balls-accurate answer the internet has ever seen

I know that Ray is a learned individual - he knows his shit for sure, but not even Mr. Spock could rattle that off in such a confident, precise fashion.

Right?

[hamerhead]

Jeez Ray - I want whatever it is you're smokin' or drinkin' or eatin' or whatever. Damn. Just....damn.

[Bloozguy]

You just made all this up, didn't you?

Well, except for the last bit.........

Damn...busted!

I know that Ray is a learned individual - he knows his shit for sure, but not even Mr. Spock could rattle that off in such a confident, precise fashion.

Not out of my humble brain...I have software that calculates thermal expansion of various materials, motion based on thread pitch, and fret spacing for different scale lengths...took about 3-4 minutes to plug in the numbers and...voila!

Jeez Ray - I want whatever it is you're smokin' or drinkin' or eatin' or whatever. Damn. Just....damn.

It's the seeds and stems...really

[coolfeel]

A mild steel truss rod will expand and contract at a rate of 0.0000073 inches (7.3 millionths of an inch) per inch per degree Fahrenheit.

If the guitar was at 72 degrees Fahrenheit and cooled to -10 degrees Fahrenheit that would be an 82 degree change in temperature.

This would make the truss rod contract 0.0005986 inches per inch of length.

A 21-fret 24.75 inch scale guitar neck is will typically measure 17.39173228 inches from the nut to the 21^st fret.

That would make the total shrinkage of the truss rod 0.0104107 inches over its entire length.

I’m not certain what threads are used on MIJ Squier truss rod nuts, but they are likely M4 diameter x 0.7mm pitch or M5 diameter x 0.8mm pitch metric threads.

An M4 x 0.7mm truss rod nut will move 0.027559055 inches per revolution and an M5 x 0.8 mm pitch nut will move 0.031496063 inches per revolution.

That makes the 0.0104107 inches of truss rod shrinkage equal to 119 to 136 degrees of truss rod nut rotation or between 1/3 and 3/8 of a turn, depending upon the pitch of the truss rod nut.

The neck wood will shrink as well, but only about 0.0000017 to 0.0000027 inches per inch per degree Fahrenheit or a total of 0.0024244 to 0.0038505 inches over the length of the truss rod.

Easy answer…yep, could have snapped from the cold...and...

Murkat can fix it.

All that talk about shrinkage...

[Bloozguy]

All that talk about shrinkage...

Biggest reason you don't pee outside in Minnesota when it's -5 like it is right now...

[Hamer Dave]

A mild steel truss rod will expand and contract at a rate of 0.0000073 inches (7.3 millionths of an inch) per inch per degree Fahrenheit.

If the guitar was at 72 degrees Fahrenheit and cooled to -10 degrees Fahrenheit that would be an 82 degree change in temperature.

This would make the truss rod contract 0.0005986 inches per inch of length.

A 21-fret 24.75 inch scale guitar neck is will typically measure 17.39173228 inches from the nut to the 21^st fret.

That would make the total shrinkage of the truss rod 0.0104107 inches over its entire length.

I’m not certain what threads are used on MIJ Squier truss rod nuts, but they are likely M4 diameter x 0.7mm pitch or M5 diameter x 0.8mm pitch metric threads.

An M4 x 0.7mm truss rod nut will move 0.027559055 inches per revolution and an M5 x 0.8 mm pitch nut will move 0.031496063 inches per revolution.

That makes the 0.0104107 inches of truss rod shrinkage equal to 119 to 136 degrees of truss rod nut rotation or between 1/3 and 3/8 of a turn, depending upon the pitch of the truss rod nut.

The neck wood will shrink as well, but only about 0.0000017 to 0.0000027 inches per inch per degree Fahrenheit or a total of 0.0024244 to 0.0038505 inches over the length of the truss rod.

Easy answer…yep, could have snapped from the cold...and...

Murkat can fix it.

How would that snap it?

[Bloozguy]

The truss rod shrinking more than the surrounding wood puts more tension on the rod just as though it was over-tightened. That, combined with the cold temperature could cause it to crack.

[Andrew]

The contraction is small, according to those figure, less than a turn of the nut.

Mild steel is less brittle and can bend more easily. But repeated temperature change will expose any fault in the metal, a weakness where the the steel is less flexible. Any brittleness could well be exacerbated by extreme cold. I don't think these temperatures will alter the crystal structure enough to induce the weakness.

[hamerhead]

I always thought the wood would give before the metal would break, so there's what I know. My head hurts from learnin' stuff.

[Steve Haynie]

The contraction is small, according to those figure, less than a turn of the nut.

Mild steel is less brittle and can bend more easily. But repeated temperature change will expose any fault in the metal, a weakness where the the steel is less flexible. Any brittleness could well be exacerbated by extreme cold. I don't think these temperatures will alter the crystal structure enough to induce the weakness.

So, there could possibly have been a crack in the truss rod before the extreme cold made the truss rod shrink?

[velorush]

The contraction is small, according to those figure, less than a turn of the nut.

Mild steel is less brittle and can bend more easily. But repeated temperature change will expose any fault in the metal, a weakness where the the steel is less flexible. Any brittleness could well be exacerbated by extreme cold. I don't think these temperatures will alter the crystal structure enough to induce the weakness.

So, there could possibly have been a crack in the truss rod before the extreme cold made the truss rod shrink?

Probably nothing you'd likely see without the aid of a penetrant dye like Magnaflux...

[a.bandini]

The Boston subway's third rails on the red line cracked due to the cold earlier this week, and it probably wasn't below 20F.

There is a phenomenon known as brittle fracture that metals, especially relatively inexpensive steels (as I understand things), can undergo. Take a preexisting microscopic flaw in a steel object, and stress it by cooling the metal down, and the crack can spontaneously propagate throughout the structure, whether it is a bridge girder, subway rail, or a ship. Things get brittle as they get cold.

You've seen similar things happen if you've ever had plastic crack in the cold.

Check out the Wikipedia article that describes how that type of a phenomenon can crack a ship in half.

So, if cold and a preexisting flaw can crack a third rail and break a ship in half then a truss rod, which is certainly under stress, and probably isn't made out of the highest grade steel, ought to be a piece of cake.

Just something else for those of us who are flawed and stressed have to worry about this winter.

[carfish7]

Ok, so my wife was sitting in the living room last night, and heard a loud "boom" coming from the garage.....

,,,,,went to head for work the next day and got about 6 feet out of the garage. Flat tire. Completely shredded in fact.

I took the wheel off and found that the coil spring on the front strut had SNAPPED, and the jagged end drove itself into the inner wall of the tire. he car was just sitting there - hadn't moved for hours but the temp was plunging again, getting down to around -10f.

I took it to the shop, and they said it was the 3rd one that DAY that had snapped - all on Ford Taurus' like my wife's (early 2000's).

It's time to consider a change of zip code. This is getting silly!

[murkat]

It's time to consider a change of zip code. This is getting silly!

That is one of the reasons I got out of MN.

Me too old for cold.

and when it gets cold there.... damm

[hamerhead]

Hey Z - I believe there was a recall on those springs. We replaced 2 for the same issue on our 2000 Tuarus. Be sure to replace both.

Here's a link and if you Google it you'll find more:

http://www.fordtaurus.net/forums/viewtopic.php?f=33&t=11773

[Bloozguy]

coil spring on the front strut had SNAPPED

It's time to consider a change of zip code.

I had one of the torsion springs on my garage door do that a few years ago when it was blistering cold...

Thanksgiving in Austin, Texas was awesome...zip code change doesn't sound too bad...but what would I do without the 4-3-2-1 club crew?