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Hey everyone. I have a simple question. I live in Tucson, AZ and I'm limited to using a screened-in garage to do all of my sawdust-making. It's very hard to maintain a satisfactory humidity level in that situation, especially always.

If I am building solid body guitars, can I store my wood and instruments in progress in a humidity-controlled area inside the house, bring it out to work on them for a few hours at a time, and then bring them back into storage without still suffering dire consequences?

All ideas are appreciated and I hope you all are having a great day!

Yes, there is absolutely no issues with doing that.

There's no magic embedded into any one certain humidity level. If OP's instruments are staying close to where they're made, I think OP would save himself a whole lot of trouble if he'd let the wood stabilize in the ambient humidity level and commence building. I think trying to force a 40 percent humidity level on an instrument that's staying in Arizona or somewhere just as dry is the definition of an exercise in frustration.

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Peter Havriluk

I'll be the naysayer. If what you build Ian ever moves as Peter rightly pointed out to another climate it could be problematic.

So my suggestion is use a quality, double action truss rod because necks move too with RH swings and a big swing from the building RH to a new RH can put a neck in back bow and make the instrument unplayable.

We see it every winter here in Michigan as the Martins, Collings, Taylors and Gibsons and others including solid body electrics lose their relief and start rattling or worse. With a double action rod this can be adjusted out. Without a double action rod and someone could be sol.

Also wanted to share an experience again that I have posted here before. When I was building acoustic guitars I took a braced top from my RH controlled shop, got myself a scotch on the rocks and headed for my back deck to so some final sanding. Within 20 minutes my braced top went flat. I did not expect that kind of movement that quickly. It all came back to where I had it with 48 hours back in the RH controlled shop. I know you said Ian you are building solid body guitars but for the acoustic set this happens and underscores how important RH control is to guitar building.

For everyone else considering getting into building acoustic guitars your RH solution and management really should be job one and it often is not going to be easy or cheap.... But it's essential.

Thanks for the helpful replies! Double action truss rods were always a given. I'm more worried about wood twistingand bending during the build process. I'm assuming if I buy properly dried wood from reputable venders of musical instruments suppliers I should be fine. I'll just have to let it settle and watch what it does I suppose!

Is it a bad idea to shoot for 45-65% or should I set my setup a bit lower to match the expectation that my first few sales will be local?

40% is where i like mine.


Steve

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Steve Smith
"Music is what feelings sound like"

IMO the key to humidity control (and cheap heating as well) is control over infiltration of outside air. It's easy in a tight shop, and impossible otherwise. If you can't tighten up the whole shop at least have a storage area for current projects, and, if possible, one good bench you can work on. As Hesh points out, things can move fast when you're working with thin wood; minimizing the time outside of the humidity controlled space helps. Keep in mind that concrete is basically transparent to humidity: basement shops can be difficult. DAMHIKT

My basement shop is real easy to regulate.

He’s talking building electrics though, I wonder if its as important?

It’s still important in my opinion. Strange things will happen to a neck built and fretted at < 30% RH if it eventually goes to live somewhere with a damp spring/summer with periods of 70% or greater RH.

I also think it’s a little short-sighted to say, well I’m only going to sell my guitars locally - people move and take their guitars with them, or sell them on eBay or Reverb and ship them across the country or internationally. A well-built guitar will be a prized possession that endure for decades, be passed down through a family or sold on to new owners etc. Who is to say it won’t end up living in a damper climate?

I have seen a brand-new Luthier-built guitar constructed in Colorado with limited workshop humidification which probably left the workshop in pristine condition but where the rod didn’t have the travel to get the neck back to straight once acclimated to the damp climate here. The builder was thinking he’d help his customer avoid winter cracking by building in the low 30% RH. Instead the neck needed surgery.

Anyhow, the OP has a plan to store wood at somewhere from 40%-50% RH, pull it out, make some sawdust and return it to the controlled space each day and I agree with Simon this is a workable approach.

I gotta say, it's pretty awesome that I have some top-notch luthiers to get thoughts from and I'm seeing an overall vote of confidence, which is good. I'm rockin 27% humidity in my projected workspace and 35% in the house with no humidity adjustment in place. Since we're looking at a couple dozen percentage points between where I will build and where my first few instruments will probably live, should I adjust my goal humidity to be lower than the 40-50% average most instrument builders shoot for? And I'll reiterate, at this moment in time I am only considering building solid body electric guitars.

UPDATE: Humidity has dropped to 17% Almost as interesting as it is concerning. I feel like I should add more hygrometers to both areas to ensure I'm getting accurate readings. This is going to become a dull side-hobby.

In my opinion, no, if the instrument is being sold to someone for real money. As a builder I think we owe our customers an instrument that can travel, so I’d be shooting for 40% RH. I wouldn’t feel comfortable to take someone’s money and hand them an instrument that could be unplayable or unable to be set up well at 60% RH. You say where they will “probably” live. Sounds like you aren’t sure? So wise to build them to tolerate a slightly wider range of conditions.

If you’re building for fun and giving instruments away or keeping them yourself then do whatever you want I guess.

Re hygrometers - there must be dozens of threads on here discussing them at length if you do a search. The summary is: you need both the hygrometer and a method to calibrate or verify that what the hygrometer is telling you is accurate. There are chemical methods of calibration and also devices like psychrometers which can provide this information. In my own workshop I use Fischer hair-hygrometers and a relatively inexpensive sling psychrometer to check the readings periodically.


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So to summarize, what you're saying is any instruments built in Arizona should be built in an environment with an RH of ~40% regardless of whether their owners will keep those instruments in Arizona, or in significantly more humid environments.

The point of the 40% is to build some tolerance for varying conditions into the instrument - it can tolerate a little dryness without cracking, it can tolerate a little dampness without swelling so much it cannot be set up. This is why most manufacturers have settled on the 40%ish figure. Keep in mind, humidity varies throughout the year in most places, many places have a damp summer and a dry winter especially if central heat is in play.

If you could guarantee, cast-iron 100% guarantee, that an instrument will stay in the desert forever, then sure - build it at 17% or 25% RH or whatever. No problem.

But you can’t guarantee that because people tend to move around and bring their possessions with them, instruments get sold, gifted, bequeathed to family when someone passes and so on. If you make a great guitar, it will be treasured and who knows where it will be living in 30 or 40 years?

I also think it’s a little short-sighted to say, well I’m only going to sell my guitars locally - people move and take their guitars with them, or sell them on eBay or Reverb and ship them across the country or internationally. A well-built guitar will be a prized possession that endure for decades, be passed down through a family or sold on to new owners etc. Who is to say it won’t end up living in a damper climate?

Amen to that! I just got an email today from someone who picked up my #10 from 2005 in New Hampshire, pretty cool! Another happy owner, lol…

A couple of more things Ian Josh are sticklers for decent RH management and control and it's also why we both brought up the necks. We are repair luthiers and we see every day what happens when people neglect the ravages of RH swings and what results from building with unseasoned wood.

I would shoot for 40 - 50% again because you have zero control what happens to your stuff after it leaves home.

Next you are telling us what you see RH wise but it's highly likely that the hygrometer that you are using is not accurate and may be WAY off. The only, only reliable way to tell the RH is with wet bulb testing or some variant of that. What those of us in the industry who have a shop full of the valuable personal property of others do is use a wet bulb test (or some variant) to calibrate a quality hygrometer that is made to be calibrated. I recalibrate annually.

Digital hygrometers are junk (and here comes the the push back, again) and everyone we test is way off. If it's not way off in the 40 - 50 range it is in the 20 - 30 range. Digitals use an electro mechanical reaction that the chemicals break down in a few years and then it loses its ability to even be close to accurate.

So for me step one is a quality hygrometer, there are recommendations here if you search "hygrometer" and then learn to do wet bulb testing. Calibrate your hygrometer, see what you have and then and only then you will have all the information you need to consider what kind of RH solution may work for you.

RH is going to be MUCH more important for you Ian if you plan to sell guitars because they will come back at you (and should) if you cut corners and produce weather vanes that move an unacceptable amount with the seasons.

To underscore what a problem this can be. I purchased a 2012 Strat new from a dealer that went teats up. My home is RH controlled and around 45% +/- a few percent at all times year around. I have an expensive, commercial humidifier on my furnace. Took the guitar home to my place and let it acclimate. Two weeks later set it up and it was great. A few days later the neck had moved. Readjusted the neck and it played great. A few days later the neck moved.... This continued to a lesser and lesser degree for five...... long..... years.

Last year I purchased a very high-end Strat-like guitar with a torrified, roasted neck. Same story the neck moved every week or so for nearly the first year I had it and it's settled down now. These are the only two guitars that I ever saw this happen to and many, many more have been brought to my collection without this ever happening, frequent neck movements.

Both guitars were brand new and both had very recently been manufactured.

So this neck movement directly impacted my enjoying the instruments. Your average player may struggle with any need for multiple truss rod adjustments and they may even damage an instrument in the process.

So with all this said I really would not recommend producing guitars in your climate for sale to consumers unless you do what it takes to control the RH or they are going to come back to you and or come to people like me who are not shy about telling clients who are mine now.... what I see as honestly as I can.

There are no short cuts in Lutherie. It may not bite you now but it will later. And let's face it too most of us get into this because we think that with time and practice we can produce an instrument superior to the commercial offerings. That's not the highest bar by the way..... And small builders can produce great stuff but cutting corners will not get us there. In some ways we have to be the keeper of the highest standards....

So I would proceed with caution, stash wood and build from your stash following guidelines for seasoning, control your RH and do it with calibrated devices avoiding digital hygrometers and expect that one of your instruments may end up in Saigon someday with 99%RH or Elon Musk may take it to Mars (if his stinkin rocket does not flip head over heels again causing the FAA to reevaluate Musk's license to fly because of public safety) where the RH is likely 0%.

Ok so I suppose my plan is to get a couple higher quality hygrometers, a reliable way to check/maintain accuracy, and keep wood/instruments in progress in that environment and hope for the best. The conditions I build these things in will improve as the build quality improves and I do expect to move at some point. Thanks for the advice!

I build solid bodies “outdoors”.
Even using H. Mahogany, I’m amazed at how much the wood moves in the neck joint.
Loose or too tight, depending on humidity.
I have to wait until a day or two of normal humidity to finesse the joint and glue it up.
We have some pretty wild temp/humidity swings in central Texas, I can’t afford a controlled shop environment.

Thanks for the tip of keeping the project inside when not working on it.

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wah
Wah-wah-wah-wah
Wah

There have been some hobby builders I believe on this forum that have said that they build a box, essentially a closet, and maintain the proper 45% RH in that very small space so that they can take what they are working on out, work on it, then put it back in. It seems to work well that way. You figure, you pull a top out to glue on some braces for like an hour or two then it's in the closet for 18 hours over night or what ever it's going to be more adjusted to that environment inside the closet then it is outside.

Hesh wrote:
"There are no short cuts in Lutherie. It may not bite you now but it will later. (snip) In some ways we have to be the keeper of the highest standards...."

Truer words were never spoken. DAMHIKT

With the additional information you provided, I still think you are fine but there are some major caveats.


Low 40's RH is where you want you control room at. Don't deviate from this. Low 40's ensures that your guitars can handle some high and low RH without breaking apart quickly. Also, 40% is manageable anywhere in the world with little effort and this is a huge reason why 43% is the industry standard.

With solid body guitars, taking a piece to work outside on for a couple of hours isn't any trouble ... but use common sense. If the outside RH is below 20%, then don't work on your guitar that day. But I stand by what I said, big chunks of wood will not change drastically in a couple of hours and the only really RH sensitive tasks with solid body building are neck attachment and fretboard preparation and fretting. You can let these pieces stabilize for several days in your humidity controlled space and pull them out to work on for an hour or so for the critical tasks. I can't imagine the humidity being an issue in such circumstances.

As Hesh stated, acoustics are far more sensitive. Bracing and plate attachment should only be done in tightly controlled environments.

What I do for necks and solid body guitars is store them in an airtight plastic container with a couple Boveda humidity control packets when I'm not working on them.

Acoustic guitars are an entirely different issue because the wood is thin and is affected by RH swings relatively quickly.