Loosening Strings to Ship YOUR bass....

[rogerbmiller]

I always detune when I ship. It lessens the odds of breakage on impact. As well, one has no control over temperatures and general climate conditions to which a bass will be exposed during shipping. So removing tension also helps to ensure that the neck doesn't bow.

 

[bucephylus]

They are folks who've had Gibson/Epiphone headstocks snapped right off in flight, due to string tension.
When the instrument goes into the hold, it's not climate controlled. Steel strings shrink faster than wood, causing extra tension, and fast.

Please forgive the TMI in this post; but I spent my career working on this kind of problem and have a more or less academic interest in it.

You are correct that the CTE (coefficient of thermal expansion) of wood and steel are different. When two materials of dis-similar CTE are coupled they do generate differential strains when the temperature changes. The differential strain associated with the thermal excursion is roughly the product of the difference in the CTE's multiplied by the temperature change.

Wood is anisotropic; but published CTE values along the grain are roughly 5 ppm/degree (ppm = parts per million or 0.000001). Steel has a CTE of roughly 10 ppm/degree.

If we allow for a 100 C transient in temperature, the differential strain between the wood and the steel would be 0.0005. On a 34" scale the extra tension on 34" steel string would be equivalent to tightening the string by 0.017".

Those are kind of rough numbers; but, the result is at least within a factor of 2.

I would not expect that kind of strain in the neck to cause damage. Handling would be a more significant concern. IMO

 

[Coolhandjjl]

If it makes you feel better to de-tune to ship, so be it. There are more important things to concern ones self with such as what 115 to go with my 410.

 

[Killed_by_Death]

I spent my career working on this kind of problem and have a more or less academic interest in it.

That's good information & I love a bit of Physics.
Did you ever encounter any experiments that took into account a shock/impact on an item under tension vs. an item not under tension, such as the headstock that has over 100 ft/lbs of tension under normal circumstances?

 

[BigBigGuy44]

I've had buyers lambast me for shipping tuned to pitch and also when detuning a bit. While I believe it is better for the instrument to remain at pitch, I always give the buyer the option.

 

[bucephylus]

That's good information & I love a bit of Physics.
Did you ever encounter any experiments that took into account a shock/impact on an item under tension vs. an item not under tension, such as the headstock that has over 100 ft/lbs of tension under normal circumstances?

That is kind of a fracture mechanics problem; and fracture mechanics gets into very deep water. Without going there, the way that works is that breakage occurs generally when there is a fault, such as a crack, which has a load applied to it such that the fault propagates. There is zero question that the kind of forces in a neck which is tuned to pitch are capable of driving crack propagation in the headstock. So, losses would tend to be observed in instruments with defects in the construction of the headstock.

That population of instruments is non-zero, and likely more common in instruments where the neck is not carefully made or the maker misses a defect in the grain. So, I have no doubt that what you are describing can happen with a combination of load and shock (mishandling). But, it should be more along the lines of infant mortality issue in better made instruments. If that makes sense. Also, it would depend significantly on the level of shock or impulse load.

 

[RHA III]

The last bass I bought here had the strings loosened for shipping. I was like ***?

 

[Killed_by_Death]

Oh, I almost forgot. My 4004 Laredo was shipped across the entire country with the strings slacked & there was no problem.
It was also pretty cold when it arrived, but I was able to dial the relief in just right immediately. Then again, RICs have two truss rods.

 

[RHA III]

Wow we can't type W.T.F?

 

[bucephylus]

That's good information & I love a bit of Physics.
Did you ever encounter any experiments that took into account a shock/impact on an item under tension vs. an item not under tension, such as the headstock that has over 100 ft/lbs of tension under normal circumstances?

Warning: off track post.

BTW, yes I did a number of experiments in the lab which led to material failure (though, not bass guitars). Most of my work in this area was on stresses and adhesion in the materials used on the chips in your cell phone. I used to look at the stresses in those materials during temperature transients between room temperature and up to 1000 C (glowing yellow). The measurements were performed on an automated system I built and were run over night while I was home with the family. The most hilarious was a gate material called tungsten silicide that I ran some cycles on, only to come in in the morning to find that the stress was zero. Looking in at the silicon wafer, it looked like someone had flicked their cigarette ashes on it. Come to find out the tungsten silicide had literally exploded off of the surface of the wafer at stress levels in excess of 2 GPa when the film went through a phase transformation. Kind of academic, but, yes I've seen my share of material failures through the years.

 

[RHA III]

Come to think of it another bass I bought here was shipped like that, and both sellers were from Northern California.

I blame talkbass, and northern California.

 

[KeithPas]

Every single time that I have received a bass with the strings loosened it has taken couple of weeks for the neck to settle back in; I don't like it at all.

 

[lug]

Being a big believer in compromise, I loosen two strings and tighten two at double pitch. If it's a ric, I tighten one truss rod and loosen the other.

 

[Killed_by_Death]

A couple of weeks?
It should be right in 24 hours or less.

 

[Slevage]

I've shipped basses in the cold winter (New England) and detuned one whole step. I let the purchaser know that when I sent it. I don't know if it was necessary, but it didn't hurt. In the warm months, I did not detune before shipping.

I replace my strings one at a time out of habit. I have had all of the strings off at the same time--- every bass I've owned--- when I had to work on them.
Never a problem.

The only one that was a pain was my Azola EUB, since it has a floating, DB style bridge.

 

[petrus61]

The neck should be kept at or as close to tension as possible at all times, IMO. If I received a bass with the strings purposefully slackened, I'd be quite annoyed because the last thing I want to do is crank a truss rod that just spent 3-5 days in god knows what type of conditions before it arrived. Leaving them at pitch and the neck at tension lets it acclimate to whatever given temp/humidity it's being exposed to during travel and upon arrival in a natural way. If the strings are slacked, the neck is not at tension and the neck is exposed to extreme temperature fluctuations while the neck is in an unnatural state...not a good recipe for success, IMO. Sure, a good neck will likely be less succeptible to those dangers, why risk it? I can't say I've ever seen a thread here about someone's neck exploding during shipping because the strings were tuned to pitch.

As far as the one string at a time thing, I do it for the same reason I stated above and that is to try to maintain a consistent tension on the truss at all times. Not a big deal either way, just a personal taste thing.

 

[Tom Bomb]

Excellent thread. Cheers!

Never a problem here. Always shipped at pitch - even one twelve string Gibson headstocks, 17º - no sweat. Hockey-sticks are a doddle.

 

[DavC]

if you're not sure ... just detune a half stepish down ...

i usually don't worry about it ... the only bass i've sold that i detuned a little was my Pedulla that was going from Tampa , Fl to Hawaii ...

i also take off all my strings at changing , as i want to clean the fretboard and polish the frets ... 4 strg bass or 6 string strat ...

 

[Gard]

I always detune when I ship. It lessens the odds of breakage on impact. As well, one has no control over temperatures and general climate conditions to which a bass will be exposed during shipping. So removing tension also helps to ensure that the neck doesn't bow.

No, it really doesn't. Check bucephylus' comments for why.

Trust me, while I'm not a physicist (thanks for stepping in with the "SCIENCE, because it works, b*****s!", bucephylus! ), I have literally multiple thousands of examples to sample from, and from a significant number of different manufacturers using different types of headstock designs. The tension on the strings has never caused a breakage issue, while the tension not on the strings absolutely has caused back bow issues. Your neck will back bow from removing string tension without removing trussrod tension, and it may or may not re-adjust properly without a problem - but if you don't detune, you don't have to worry about "may or may not". Removing trussrod tension and string tension will eliminate damage opportunity, but then induces the need for a full setup at the end of shipping, and does so for absolutely no gain in safety during shipping.

This is a question of facts versus misinformation and ill-formed and unsupported by science opinion. Don't detune your strings for shipping.

 

[RedLefty]

I am sooo going to do an FEA on this and post results. I love investigating snake oil

Could someone give me headstock suggestions for the best and worst to test?

I am an engineer and FEA would provide some visual results that I think the people here would like.