Temperature changes and neck movement

[jazzyvee]

Due to space limitations in my music room due to windows chimney and radiators, my basses and guitars are stored in their cases in a large thick oak cabinet against an outside wall. The past couple of weeks has seen a snap change in the weather with a drop in temperature. Since then a  few of my alembic basses have had neck movement resulting in choking of the E, A, D, G strings between the 3rd to 6th frets. The bass i picked up to take on my gig today was like that but i still took it because i thought it may get back to normal after a 4 hr drive in a warm van. As it happens we got to the venue with only time to line check and start the gig so i didnt have a chance to adjust the truss rod before showtime.  Anyway with a really light touch and moving my basslines higher up the neck where practica i got through the gig.
But i would like to know if there is any long term damage to the neck that could happen as a result of the bass being stored in a lower temperature for an extended period of time before spring returns.
im on my way home now and will try to move the cupboard a bit further away from the wall to see if that helps. as it happens none of my guitars or short scale basses stored in the cabinet were affected only the long scale 5 string basses and i don't recall this happening so suddenly before.

[lbpesq]

Jazzy, was there by chance also a change in humidity?   In my limited experience, concurrent changes in both temp and humidity can wreak havoc with relief.   I’ve never encountered anything permanent, though.

Bill, tgo

[jazzyvee]

Hi Bill, thanks for responding. I have put a temperature gauge on my desk by the wall when I left for my gig earlier and the humidity is now showing 60% which is the upper level of what the gauge considers normal (40% to 60%) which i presume is normal for humans and it has been within that range during the summer. The temperature on the wall the cabinet is backing on to is showing 15 degrees C when usually it's about 19 or 20 degreesC
. I don't know what is a good temperature to keep a room with musical instruments in. Any suggestions?
 

[JimmyJ]

Jazzyvee,

I think you worry too much.      I used to live in Minneapolis and there were times when the bass would get extremely cold.  And yes, that and the dryness of winter's indoor heat would definitely have an effect on the action.  That's probably why I carry a small screwdriver and truss rod wrench in every gig bag or tool kit that I have.  It doesn't take but a couple minutes to throw some relief into the neck or try to pull the strings back down within reach.  It's the nature of our wooden axes.

I have heard people say you should try to avoid shocking the instrument with sudden temperature changes.  If the bass has been parked in a truck for a couple days in cold weather I guess it's best to let the case warm up for before you take the bass into the sauna.  But that story may mostly apply to acoustic instruments with thin tops and backs under sound-post stresses, etc...  Our basses are very solid machines - built for the road!


Jimmy J

[StephenR]

IMO it is impossible to completely eliminate the need for the type of neck adjustments that become necessary after temperature/humidity changes or changing string types and gauges. Some instruments fare better than others when the temp/humidity changes but it is always a good idea to check the setup periodically, definitely a day or two before bringing to a gig as well as the day of the gig, and especially during spring and fall. It is normal to have to make adjustments unless you have an instrument where the neck never moves which I find to be rare.

I am guessing the primary reason you are seeing more need to adjust the neck of your long-scale bass is due to the larger orbit of the strings that is unavoidable as scale length increases but it could also be partially related to the stability of the wood used in that particular neck, each is slightly different. Older instruments will stabilize over time, as the neck wood matures I generally find less need for any large adjustments. I agree with Bill that you do not need to be concerned with any long term or permanent damage from storing your instruments the way you have been, and with Jimmy who always chimes in with well-reasoned advice.

[David Houck]

The symptom you described suggests that neck woods were expanding, not contracting.  If the temperature was affecting the neck, cold would cause contraction; so I'm thinking it's not the temperature.

You said that the relative humidity is currently 60%; this seems to me to indicate that there is a lot more moisture in the air now than in the summer when the relative humidity was also 60%.  Usually relative humidity decreases in the winter.

So my guess is that your issue is related to humidity.  Has it rained there recently?

[jwright9]

Must disagree. Contraction would cause the neck to tighten which corresponds to the issues described.
More tension with contraction thus lower action. Too low. Strings hitting frets.
Expansion would happen with increased humidity and cause relief of tension and higher action.
The cold and dry winters are often the culprit of the tightening/contraction.
Just loosen (left turn) the truss a 1/4 turn and that should do the trick.

[jazzyvee]

David, it has been raining heavily and virtually daily for quite a few weeks now and my heating has been on much higher to keep the home temperature comfortable. That room is one of three in my home that never reach a consistently even warm temperature in autumn, winter or spring, there are always cold spots and the outside walls cold to the touch. Fortunately there are no damp areas. Im trying to understand the difference between both answers by David and j9 about the neck movement. As the neck has a metal rod in and different woods each of those would expand/contract in all directions differently to temperature and humidity so i imagine its a complex situation with hopefully a simple remedy of turning nut. Im gonna try some adjustment some time today. Thinking back, that is  same bass I took with me on a caribbean cruise gig and the neck moved resulting in choking in the same area and i think i raised the nut to resolve it and lowered it back when i got back to England. Thanks as usual for your inputs. I do have an annual heating service call soon so i will see about getting the plumber to move the radiator in that room so that the storage cupboard can be relocate to an inside wall.

[jacko]

Think yourself lucky you're not up here in Scotland Vee. we really do get all 4 seasons in a day and temps / humidity go up and down more than a yoyo.  I changed strings on my BalanceK a couple of months ago (still my standard black beauties) and because of the weather here I've been fighting with the action virtually every day. First thing I do when I get to a gig is sit the bass on a stand out of the way somewhere so it gets a chance to acclimatise to the venue then, as Jimmy says, give it a quick tweak if neccessary.  I think this really only affects neck through instuments though - My epic never seems to move.

Graeme

[David Houck]

... it has been raining heavily and virtually daily for quite a few weeks now ...

That seems to further support the idea that it's humidity.  What I would do is loosen the truss rod nuts and let the tension of the strings pull the neck back into relief.

Despite all of its laminates, my bass is very susceptible to changes in humidity.  When the humidity goes down, the wood contracts, and the string tension pulls the neck further into relief.  When the humidity goes up, the wood expands, reducing the relief.  Because of the frequent humidity changes here in my house, I frequently make truss rod adjustments on this bass.

The second thing I would try if that doesn't get you all the way to where you need to be is to adjust the bridge just a bit on whichever side is still buzzing in combination with your truss rod adjustments to get a good action up and down the neck.  I wouldn't mess with the nut.

As J9 suggests, it is good to get several opinions so that you have lots of information to draw on.  My memory being what it is, I have to think through what I write to make sure I'm not getting it backwards, which is why I don't post to the troubleshooting section as often as I used to.     Getting older makes daily life more adventurous.

[keith_h]

While I didn't live in Minnesota I did live in the Chicago area for many years and still consider it home. I never worried about the frigid cold that much with my basses. When playing gigs they would travel in a box truck along with the rest of the equipment. All I would do when we got to the venue is crack the case open and by the time we were done setting up it was usually up to room temperature or at least at a temp that was comfortable to play. To be honest I was more concerned about condensation in amp and other electronics coming from the cold into the higher humidity of the building.

Like others I think it was humidity more than temperature that caused the neck to move. Mine are generally pretty stable once they go through their twice a year change of season adjustments. I've found even during the active times of the year if I adjust the bass it takes a day or two for it to be noticeably out of adjustment. If for some reason a neck needs a tweak I always have adjustment tools in the case.
 

[pauldo]

When I was gigging in Milwaukee I did the exact same as Keith... cracked the case open and let it set while setting up.

My bass does have (at close scrutinizing inspection) some fine ‘crackling’ on it’s finish.  Might have opened the case too quickly on an occasion or two. This doesn’t trouble me at all as the sound of the bass negates any cosmetic concerns.

Not sure if my action is higher than others, but I have yet to adjust my truss rods since owning this bass.  I have tweaked the nut and bridge height slightly on occasion.  She still (as my friend says) “nearly plays itself”.  The action is comfortable and easy.

[KR]

My '77 Series 1, with Swing Bass 45-105, requires a loosened truss rod when in average to higher humidity---actually loosened almost all the way sometimes and then tightened just enough to keep the truss nut barely snug. Conversely, I just had a 4-day casino run in Laughlin, NV, with very low humidity, causing my '77 Series 1 neck to bend in a pronounced forward bow, and also causing the fret ends to stick out just a bit---yes, that dry. To correct this bow I pulled back on the neck with my left hand, and while manually helping the neck to become straight, I carefully tightened the truss rod nut in small increments each time, totalling almost a half turn over the course of an afternoon===always holding the neck in a back-bow while tightening the truss nut. I firmly believe the early Alembic rods are for fine-tuning, and not for pulling a neck into straightness. I would never try to straighten an early Alembic neck via the truss rod only. I then addressed the fret ends myself. Just love my '77, and always brings tools to keep it playing well. It generally needs no tweaking except in extreme conditions like Laughlin dryness. If my neck ever becomes too straight I will loosen the rod and be sure to keep tuning tension on the neck.   

[lbpesq]

Interesting suggestion regarding truss rod adjustment on early Alembics.   I can’t say I’ve heard that before.  What is there about early Alembics that is so different from later instruments? 

Bill, tgo

[KR]

Hi Bill. Mine is the early single truss rod system. The rod used in my '77 Alembic isn't a modern, large diameter one like most modern basses. It's very much like the truss rod in my early Rickenbacker 4001--back then Rickenbacker required users to manually assist the truss rod when straightening. I actually -help- all of my different makes of basses when straightening the rods--I can't afford to mess up my collection with a busted truss rod. This method is what many repair luthiers do as a rule just to be safe. It's a personal opinion and preference, and I just offer it to the club to hopefully help, and to prevent any problems that can arise when adjusting a rod. I've included a link to a discussion w/pics of a mid 1970's Alembic with a single broken truss rod from over-tightening. It shows the original, smaller diameter busted rod, and the the newer larger replacement rod. Because the neck lams make the Alembic neck very sturdy, a large rod wasn't really needed for the mostly minor adjustments these basses require. Small tweaks are all my '77 Series 1 ever needs. The Laughlin Dryness incident--lol is an extreme example of having the tighten the rod a lot more than usual, so helping the neck with a backbend is appropriate, in my opinion. I personally wouldn't put a bigger rod in because of the tone change. https://www.talkbass.com/threads/replacing-the-truss-rod-in-an-early-alembic.1347719/