Is this normal for your area or is global warming coming for the guitars as well?
Troy do you treat your necks with anything after you change strings? Just wondering - not saying that it would have helped in this situation, but I’m curious. I use gorgomyte on mine or Big Bends Fretboard Juice just depending.
I have not! I just know that before I made any adjustments, the typical string press at the 1st and 17th frets gave me no air gap at all at the 7th fret - it was metal on metal. When I loosened the truss completely I now have .010 on my feeler gauge. So still a little low, with nowhere to go to adjust. And some of the top strings are buzzing with the saddles on the high side. So things are not quite right, and I think I need to get the relief part sorted first just to eliminate variables.
Edit: In re-reading this, I guess this probably qualifies as “measuring the amount of relief”. The caffeine hasn’t kicked in yet today!
Did you measure about .010 relief at both the high e and low e side of the fretboard? Maybe you have less relief on the high e side (slightly warped neck).
.010 is considered a pretty substantial amount of relief! You should only need a hair. A lot more and you could be getting into the area of causing it’s own problems of too much relief.
I did not measure both sides but I will do so in a moment.
As far as the amount of relief here, this is strung up at tension with the truss rod totally loose. So basically, this is the most possible relief I can have. And if the humidity changes a hair and the neck straightens out, and it will as it gets colder and drier here, I have no way to bring it back.
Is this really a thing? I’ve seen how temperamental the action on acoustics can be with humidity variations, but that’s mostly to do with how thin the top is. (Humidity makes the wood swell and the bridge can move up or down as the top expands or contracts.) Electrics don’t have this problem as they are much thicker wood, and usually finished in something that keeps the moisture out (poly or nitro). The only effect of humidity that I’ve seen on electric gutars is in the fretboard (the aforementioned fret sprout). Not saying that’s the only effect, it’s just the only one I’ve seen directly. I’m curious what other people have seen.
So I guess I’m wondering
- What kinds of guitars you’re talking about (electric/acoustic, brand/model)?
- How exactly does low humidity straighten a guitar neck?
Totally. By mid winter, the action on all my electrics is different and the frets are all sprouting. The other day I was in the studio working and the temperature was dropping rapidly, it was changing as I sat there. By the end of the day the strings were all rattling. It was unseasonably cold that day and they shut off the heat on the weekends in our office building.
I can’t give you the technical explanation for why this happens, and I’m probably as surprised as you how obvious it is. I’m determined not to let that happen again, and now we have nice reasonably sealed studio we can humidify. At home though I’m not sure how much we can do - it’s an old building and super drafty.
You had this problem last year, if I recall correctly. Being the owner of guitars that all have unfinished maple necks, I say again: you have to get the humidity in that room between 35-40% and keep it in that range. I don’t care how drafty the room is, you can do it. And it’s not the insulation or leaky seals (those are probably helping a little bit), it’s the dry heat being pushed into the room that is driving the humidity down. Buy a humidistat for $10 to $20 and minimize fluctuations as much as possible. Finished necks will react more slowly, but as you can attest will still dry out and start to fight against the non-organic material in the neck—truss rod, neck, nut, etc.
You are correct about the humidifier too. Buy one that is evaporative. Depending on the design and the content of your water, you might develop some scaling issues from the stuff left behind. There are some quick solutions, if you google. I personally use good ole vitamin c that you can buy in bulk on amazon. But I believe some people also use vinegar and other natural solutions.
Put open containers of water on your heat source as well—this is a free solution that can help a little bit but will not be a stable solution. An old pot on the radiator is that’s what you have; a glass on the vent if you used forces air. Whatever it is, the water will evaporate into the room slowly and naturally.
Also, the same cuts the other way. If you get a ton of moisture in the summer because if AC, the you need a dehumidifier. Our house for example can have humidity over 60% when temperatures rise. This is actually harder to control, in my opinion, because even good units have a tough time removing humidity from cold air and keeping things under 55-60%, but a good dehumidifier can keep things right where they need to be.
Hope this helps.
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Hey Troy, yes NYC is brutal on all my instruments. I would highly recommend keeping acoustics in cases with dampits. Also a humidifier but you are already on that. In my experience when it gets dry the wood shrinks and necks get more bowed, whereas when it gets humid they get straighter. Meanwhile the opposite is true with the body, on acoustics when it gets dry the top sinks lower making the action lower. When it gets humid the top expands and bulges our making the action higher. It also seems to happen a little on electrics, despite being solid wood and metal bridges. But certainly the guitar dimensions change a little even on electrics. One trick for a truss rod that is all the way tight but the neck is still bowed is to take the truss rod nut off and insert a washer in there and put the nut back on. Then you get a bit more tightening range. But this sounds like the opposit of your problem.
It arrived today! Unlike the slick computerized ultrasonic one, it’s basically just a bucket with a fan in it. But it works quickly here in the office, which is relatively decently sealed. Brought the whole place from 30% to 45% in probably less than an hour. The trick will be seeing how well it works in a drafty house. Here’s the one we got:
It certainly is! I spent some time checking out expensive humidifed cases just because I assumed the leaky bucket we live in would prevent humidifiers from working well. But who knows - we’ll see.
To add to the fun of my studio in an old cow shed, a mouse appears to have eaten its way in through the roof insulation. Well, it started on the insulation, now it seems to have moved on to nibbling the ancient wood that holds the roof up.
Fellow NYC resident here.
I have a pretty nice Air-o-Swiss humidifier that I keep going during the dryer months, aiming to keep humidity at home around 45%, and my guitars are generality fine. I have a practice space up in Greenpoint that gets a little dry, but I don’t keep any of my nicer gear there.
You should know the NYC radiator trick -
If you have old-school metal radiators that you can’t control and are either off or 90 degrees (common in NYC), a good hack is to keep metal pans of water on top of them. The water evaporates and humidifies the air. You’ll be amazed how fast it evaporates.
Back to the top post, if you have 12s pulling on your neck and the truss rod is slack and your neck still doesn’t have relied, you’ve got some back-bow problem happening with the neck, or maybe a problem with the truss rod. From what I can tell, Dan E is pushing the neck into relief and then tightening the truss rod to hold it there.
As @Troy suggests, he’ll need to do the reverse, but I think will only be possible if you have a double-acting dress rod that can push the neck intro relief -f it’s an older guitar, the single-acting truss rod is likely only capable of applying backwards pessure to counter-act string pull.
The cure for this is more involved - essentially forcing the neck into some backbone with clamps and applying heat and trying to coax it into “sticking”. I’ve also seen it solved on vintage guitars with more extreme measures involving removing the fingerboard, and working the maple neck with the truss rod removed.
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How’s it working? How drafty the house is shouldn’t prevent the humidifier from keeping things relatively stable—just might have to refill the water a bit more frequently.
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That’s probably the case here. If I can clamp into relief, then set the truss to pull it back, that would be cool. I’d like to have the truss be somewhere in the center of its range of travel, so I can effectively move it in either direction. From the sound of it that may not be realistic.
Hard to tell, we just dropped back into the thirties again yesterday so I only have a day and half with the humidifier. But it ran through four gallons of water overnight, ran the tank dry, and then the house dropped back down to 21 percent by the time we got up. Filled it back up and running it set on 45% as I type this so we’ll see.
I suspect that even once all the wood in the house gets saturated, we’re still going to have a situation where this thing will need to run hard all the time on really cold days to keep things stable. It’s an old, drafty house and that may just be the way it is. Maybe we’ll get another one so the refills are less frequent. Who knows.
We’ll see!
Are you humidifying the whole house or just your studio? If just the studio, that’s crazy! I stand corrected. That is a massive fluctuation for a few hours. It would take a week of very cold days in addition to using the fireplace for the humidity in my house to drop that much. Can’t get my head around that. My guitars would be unplayable.
Troy,
Typically in the dry winters, the neck should go into a forward bow aka more relief.
I see two observations:
You saying it “goes totally straight”
vs.
You hearing it buzz.
Considering the guitarist you are, I trust the latter, and that brings me to:
It’s probably buzzing but for the opposite reasons. It’s actually probably gone into excessive relief, reducing next fret clearance and thus contributing to buzzing. Counter-intuitive perhaps, but ceteris paribus, a lower relief or flatter neck will result in a greater next fret clearance, which is the answer to buzzing, considering your frets are relatively level.
There are some very rare cases in which the wood moves the opposite way- that the neck becomes reverse bowed under dry winter weather, but my reply does not pertain to that rare example.
If you could give me a general reading (numbers, descriptions) of the neck relief (press first fret and 16th fret and I need a reading of a gap in the 7-8th fret area), action height, and general state of frets, I’d be able to give you more specifics.
Hopefully you get it sorted out. A humidifier is a good thing not just for guitars but people like me who hate the dryness and its effects on my sinus.
Can you explain why this happens?
Typically wood retains its original shape best around 40-50% relative humidity (and 25 degrees C ideally).
What happens in low humidity (characteristic of dry winters) is that the wood is no longer in that state, and the wood, trying to maintain equilibrium with the surrounding, shrinks because it’s losing moisture. It’s small but it’s enough to cause a difference. That’s why frets “sprout” and in many cases the neck caves in the middle likewise as a loss of this wood volume. The adj. truss rod was invented to counteract and balance weather extremes so that we don’t need to play guitars in such ideal conditions all the time. As to why exactly it caves in the middle, wood tends to have this “cupping” effect that can be best explained by a wooden dish/disk that takes on a slight concave “U” shape at either end during dry seasons- primarily due to the grain orientation.
Thanks. The changes in the wood I think I understand, it was the direction I was wondering about: Why does dryness lead to more relief instead of less, i.e. why does the neck bend forward and not backward?
The grain in a guitar neck generally goes lengthwise, which, if I understand cupping correctly, means that the cupping effect would tend to warp the neck crosswise, not lengthwise.
Now that I think about it, it seems more likely that the directional asymmetry is provided by the string tension, which I missed because I was thinking about the effect of temperature and humidity on wood, and ignoring the strings altogether in my mental model.
Apologies for the late response. Let me amend my explanation, although the general correlation of low humidity and increased neck relief still stands.
Humidity affects the volume of the wood but not the truss rod (outside the quantum world), and when wood shrinks, the pressure exerted by the rod on the wood is less, hence the forward bow. In the reverse case of high humidity the wood swells, resulting in the pressure applied by the rod to the wood to increase, hence reducing the relief. Kind of nature’s way of “loosening & tightening” the rod, even though the rod itself isn’t being loosened or tightened.
This is most often the typical case, and the cupping effect should apply to statistical outliers- and could be an explanation for neck twist or necks moving the opposite way as normal, but isn’t too relevant here so you’re absolutely right within the context.
Not sure if I understand your idea of directional asymmetry correctly, but assuming a 010 gauge set of strings, the tension on each string is relatively the same either way. The string tension is only secondary to the primary forces which describe how the changing size of the wood and truss rod effect concavity in the neck, meaning even without the strings, the concavity will still exist just to a lesser degree since the strings aren’t affecting it yet. In other words, the force exerted by truss rod on wood (and wood on truss rod) is always there, though once you put the strings on it can compound this effect (ie. low humidity neck leading to less pressure on rod leading to a concave area in the middle which is further compounded by the string tension).
Ex. if you observe with a straight edge the state of the frets before stringing a guitar (assuming the frets are a good proxy for the straightness of the board itself) and it’s observed to be .010" in the middle, then it’ll only result in more relief with strings on, and almost unplayable by then. Likewise, if you take the strings back off the concavity will be reduced, but it will still be there (or even go into a back bow- since I like my necks with zero-relief once strung up).