Official Luthiers Forum!

Just read a thread from way back in December where two OLFers describe using a shop that was once used for furniture making so it should be fine, humidity wise for gutiar building, right?

Wrong.....

The big difference between the two endeavors, furniture and musical instrument building is with musical instruments we often use very thin plates that are minimally supported so that for example the top can move with vibration. If your coffee table moved with the vibration from the surround sound that would not be a good thing now would it....

Guitar building is completely unforgiving of not maintaining rigid humidity (RH) control. Thin wooden plates move expanding and contracting as they absorb moisture.

Last year we worked on a small builder instrment, it was number 141. This builder was experienced or was cheating on his serialization scheme.... but since we know him this actually was number 141.

The owner had a 5 year old Luthier built guitar, number 141, that was not built with strict RH control. The instrument had been in the shop at least once a year for it's entire 5 year existence.... Every time the seasons changed, hence the RH changed as well the action changed, the neck went into back bow, the top cracked, and this instrument was spending more time being fixed than it was being enjoyed....

The owner paid thousands for the instrument and at the five year point we had a discussion where we advised the owner that this would likely never stop. Repair folks cannot make up for building without strict RH control.

At the time of this conversation the instrument had nearly 10 top cracks, the bridge had been reglued twice...., the neck needed to be reset (expensive) and generally speaking there was nothing of value left to say about this instrument. We advised the client to consider, unless they had reasons not to...., making it a wall hanging unless they could not stand to look at it any more.... With the repairs and the initial cost of the instrument they bought it twice.... and only received 5 years of limited, intermittent service from it.

The client took our advice and bought something new and here is the big point - the client was unwilling to ever trust an individual builder again, any of us..... We all now had a bad reputation because of this one, poorly built instrument....

Now I know that some don't sell or have commercial interests with Lutherie but just the same heirloom instruments which is what we are building may mean a great deal to whom ever you give it to or build it for. As such you want it to last and last.

A properly built and cared for guitar should easilly last 100 years in my opinion. Granted this would be with the best of practices and the best of care but still why not shoot for the very best that any of us can do, always!

Please understand that RH is more important than the band saw that we might want to buy or any tools, chisels, etc. Step one with gutiar building should always be securing an envirnment that has proper RH levels for where you are building and what guitars require. You will also find that there are far fewer mysteries as well when using well seasoned materials in a controlled RH envirnment.

When I started no one told me this but I once read a post on the OLF early on where a member described how very proud of his first he was and that he had finished spraying 3 weeks ago only to be woken up in the middle of the night by a very loud crack sound.... He said that he knew what it was at once and sure enough his new one and only guitar had split right down the front.... after finish had been sprayed as well.

RH is important - please remeber this!

Also most hygrometers are far from accurate and there is a lot of information on the OLF if you search for how to evaluate the accuracy of a hygrometer.

This has been a public service announcement.....

Right on Hesh! I have had a few of mine come back where the customer did not properly humidify the instrument... you know the story, my guitar is buzzing and the fret ends are sharp.... wonder why? This is very discouraging to me as a builder, I am seriously considering including a Humudipak with my instruments.... but still can't make them use it!

Rant over
Chuck

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If the customer will not take care of his instrument and leave it in a bone dry place, our responsibility as builder has ended.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

It is true that it is the responsibility of the customer to humidify the instrument. But if the guitar is built during humidity fluctuation as Hesh describes than humidifying won't help. It is a different issue.

I too have seen instruments that were not built under strict humidity control. One of them was fine in the summer, and then developed 2 - ¼" wide cracks in the back in the winter.

Humidity matters when building and I don't build unless I have my shop maintaining a stable humidity level of 43-45%. Which normally isn't an issue, but this recent cold snap has made it a little harder to keep the humidity up. I can't wait for spring!

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

I dunno I'm much more inclined, Tai Fu to be there for my clients and this includes a healthy dose of education about the care and feeding of a fine acoustic instrument as well. I always have this talk with my clients and in my repair world I'm having this talk every hour today....

I deliver my guitars with a healthy discussion about humidity, an owner's manual that stresses that all bets are off if the instrument is allowed to dry out (I'll still do all I can but I have to take this position for the people who really are abusive....) and I have a delivery check sheet where I place a check by the item for discussing RH, the item pointing to in the mnaual where I discuss RH and owner responsibility and then I go over this with the client. I also have them sign the check sheet that I'm delivering all that I indicate that I am inculding the education component.

You are right Tai Fu that we do need to draw a line. I'm just willing to draw it one place and error in favor of the client but not say this in advance.....

So far none of my clients have let me down, in the repair world it's very much a different story, repair the thing, discuss why it happened, they go away and come crying back in a week with sharp fret ends and a buzzy beast....

Chuck good going and I think that you have the bases covered. You are right we can't make people do things but we sure as heck can do all that we can to make it all understandable AND cover our butts too.

40% or bust, baby!

RH of 40 % is not the silver bullet........! At best it is a compromise that fits the upper and lower variations in the largest number of places. If the guitar lives in an area that is constantly dry then 40% or in an area constantly more then 40 %, the guitar is under stress. But years of experience by vast numbers of builders, both pro and amateur have shown that about 40 % is the best bet to fit the largest number of situations. The best RH for guitar building is the RH the guitar will live in. Given that it does not take away from the importance of knowing the RH in which one is building.
Tom

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A person who has never made a mistake has never made anything!!!

Ed, I keep my shop between 40% and 42% all year around. Doesn't help a guitar in the winter when it is out of the case in a non-humidified forced air heated home where the RH is around 20%.

Tai Fu, you are correct that we as builders are not responsible when a customer allows an instrument to be de-hydrated. But, like Hesh, I try to error in favor of the customer.

Hesh, I like the idea of making the client sign off that you explained proper humidification for the instrument. I may just incorporate that idea in my warranty, thanks.

Chuck

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You know Ed I am long winded but all I meant to say was what you just said!!!

Yeah it might be helpful and in my experience when folks have to sign something they tend to be sure to be awake.

When I got serious about selling I wrote an owners manual, a quick start guide including the proper way to put string on, and a check sheet for things that needed a discussion. I've always included a quality humidifier for the guitar too and quality cases.

Back then I had just moved back to the area that I grew up in, or.... tried to.... and no less than three of my parking lot, school skipping, local crime wave buddies who I went to high school with, or hung out outside the building.... are now local attorneys. So I got together with one of them who is also a judge now (go figure....) and had him vet my documents and approach. He made a few corrections, told me that I was too long winded.... (I'm used to that...) and went from there. I thought about contracts for artist promotional deals too since I had a couple of those but decided that my primary focus would be shielding Heshtone here from unwanted liability going forward.

Anyway just because we are small builders does not mean that we have to subject ourselves to the business ethics of buying a Rolex in a parking lot...

I've been very fortunate and in addition to this I also offer anyone who purchased one of mine lifetime string changes. Now before anyone thinks that can get expensive this gives me an opportunity to revisit my stuff in some cases frequently and can add in reinforcing the education process as to the care and feeding of a high performance, wooden instrument. It's also a good time too to see my kids come home.

Great post Josh and I could not agree more with ya.

Mario P. was who introduced the OLF to the idea of also shipping instruments with two saddles, a summer saddle (lower) and a winter saddle, higher. It's a great idea and any time that you can safely help clients help themselves it can be a very good thing.

Take it from me, I had very basic RH control and monitoring in my shop in FL prior to this beauty... It turned out that my Hygrometer was not accurate and I braced the top at 70% RH!! I then assembled the guitar, and finished all construction, including a full abalone perimeter. A few weeks later, a drop in humidity down into the 20% range caused the top to split right at the glue seam. (Turns out I had used a bad batch of glue from LMI that was later recalled which didn't help.) I ended up having to retop the guitar in order to repair it.

Of course I invested heavily in RH controls and calibrated Hygrometers prior to repairing the guitar. Hesh advised me on my mistakes when the damage occurred, and now I feel very confident in
the longevity of my instruments, thanks to the advise seen here. Not to mention, the damaged top caused me several hundred dollars in wood and abalone, and I'd hate to see someone repeat my mistake.

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Chris Alvarado
www.ChrisAlvaradoLive.com
www.Driftwood-Guitars.com

Chris's example above is exactly why I say a bad hygrometer is worse than no hygrometer. At least without one you have a random chance of it coming out right.!
Get a good hygrometer and keep it calibrated.

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Jim Watts
http://jameswattsguitars.com

It's not absolutely necessary to control humidity in the entire workshop. The smaller (and less 'leaky') the environment the easier it is to control. That can range from reducing the assembly space in the workshop through to building a 'conditioning cupboard/box'. My dehumidifier reduces the RH by 10% maximum. That's perfectly aqequate a lot of the time but sometimes I have to resort to conditioning the wood parts in a cupboard. Heat or a very small cupboard dehumidifier can easily control such a small environment. . . . and it's cheaper on the old electrons.

Hey Chris! Yeah I think that I remember that but I'm also very glad to hear that you got it all squared away.

Make no mistake about it getting the RH thing down for where each builder is can be difficult at times depending on your location. In Florida I suspect that you guys are dehumidifying in the summer but dehumidifiers produce heat and summers are hot so that must be a bear to deal with too.

Jim makes a great comment that I will try to distill - nearly all hygrometers suck and are not accurate.... And this makes it even more difficult but once we know these things we can work around them.

Sure it can be done but I'm not keen to recommend the idea of having a RH controlled box or closet and that's it.... I once took a top on my back deck to sand, the RH in the shop was 45 and on the back deck it was 55%. Within 20 minutes my top was flat and I was racing for the shop, radius dish, and some bricks to weight it back down.

I've also known lots of builders though the years that could not make the box thing work well for them. Stuff happens, the phone rings, etc. people forget and stuff gets left out.

At present some of us have been trying to help Mike-P and I think that somewhere in all of that interaction he mentions that he is not controlling the entire shop either and he has had issues that could be RH related.

Michael not trying to argue with you and I know that you and I do not get along and normally I would not even say this. But I want it to be clear that my disagreement with you over recommending building out of a RH box has nothing to do with the fact that I find much of what you say to be unsound but it has everything to do with the idea that building out of an RH controlled box is by no means a good solution without it's own issues.

Instead even if one has the smallest shop folks will have more success and options if the entire space meaning where the work is done, where wood is stored, where work-in-progress is kept is strictly RH controlled. There are also ancillary issues that are aggravated by this notion that one can keep an easy bake oven or RH controlled box and call it good. Finishes, glues, etc. all cure more reliably with both temp and RH control.

Sure we want to make it easy for folks to get into guitar building and no one ever will have to tell old big mouth here this but my personal take is that if we understate the important things such as RH in an effort to promote the hobby/trade and folks take our understated advice and fail.... it's on us and we caused the failures by not being perfectly clear that...............................RH is important. The quality of the advice and info that I might promote is also super important to me..... and understatement.....

So I'm not fighting with you, Michael, likely won't respond further based on the history of your interactions with me in the past and NO offense intended.

But.... I do NOT agree with the idea of promoting the notion that a box and a light bulb is all that's needed to call it good and enjoy carefree building and a claims free warrantee going forward. Most pro builders invest heavily in RH control, f*ctories invest millions, and there is good reason for this too.

RH is important!

You can buy a small or closet dehumidifier. You can glue up and put the whole set up back in the cupboard (if it's large enough), clamps and all. I never said it was an 'ideal' but it's a workable solution. If the hygrometer says it's 45% in the cupboard. . . it's 45% in the cupboard. You can measure it at various points in the cupboard, just as you can in a much larger workshop. Think of it as a very small workshop. You don't have to glue every single brace on in one operation but you certainly can if you want to. It takes me less than 5 minutes to glue all the Back braces on. Much longer than that and it's very likely that I've been too slow for the glue anyway.
I have a UV cupboard for drying Oil varnishes and tanning the wood. By itself the humidity plunges to dangerous levels. It will distort a plate within an hour. I know because when I first built it that is the very thing that happened. A baby bottle warmer steaming away at the bottom of the cupboard was the solution. That was nearly 12 years ago and I haven't had one single distorted plate since.
Not everyone on this forum is a Guitar factory or indeed a Professional builder. They can ignore my advice, most likely because it wasn't addressed to them!
I rest my case.

Hesh,
The best essay on humidity control I have ever read, for including with a new instrument, was published here on the OLF a few years ago. In my mind I want to attribute it to your partner David Collins. If my memory is correct perhaps David would consent to re posting it.

I know this is a bit of a hijack but humidity control is as important after delivery as it is during construction. I have to be really aware of this as a lot of the folks in my area heat with wood stoves in the winter. Nothing dries out an environment like a wood stove.

Cecil

Hey Cecil!

I'm sure Dave would be great with reposting any post that he has ever made on this forum. That's why he posts!

So please feel free and I'm wondering which post it was that helped you out to the degree that you can recall it.

As some of you guys know we make our livings doing repair and restoration work and we do a heck of a lot of it too.... The past couple months have been our busiest time of year as always. Folks are confined to their homes because of the horrible weather and out come the guitars.

The last two winters here in Michigan have broken hundreds of Michigan records with two being broken in the last 5 days.... It's often -10F or worse and since everyone's furnace is running non stop instruments are cracking all over the state. And then we see them....

I can't tell you how much of my days lately have been consumed with teaching folks about RH and why their guitar cracked and why it will again in short order even after we repair it if they don't do what it takes to protect their instruments.

With no exaggeration here it's likely that I spent over an hour yesterday alone advising at least 5 folks in person and a similar quantity of folks on the phone as to why their fret ends feel sharp, necks are in back bow, the strings decided to visit the frets, tops sink in, bridges lift, and of course their guitar decides to further ventilate itself.....

We also have, unfortunately.... clients who think that one way to control RH is to bring us the instrument for say a simple set-up in early November and then refuse to take our calls until the following April.... We have limited space and I am well known for getting on folks about picking up their property in a timely manner.

Although I I'm not a life long Luthier I do bring some other things that are very applicable to a Lutherie repair business with me. Expertise in JIT, Six Sigma, Lean manufacturing, etc. all come into play in how we carry out our work flow. I also have a background in the early work flow software packages that were licensed to large enterprises.

As such a simple set-up is usually returned to the client the very same day.... But.... these days it's often the case that we have to bag em and tag em for three days or so to restore the geometry of the instrument before doing the set-up is prudent.

We have one client who lives in a dorm, cracked his guitar, we fixed it and sold him a guitar humidifier as well and three days later he's sad because his guitar cracked again.... When it came back the crack was wide open enough to see into... the fret ends were again sharp and the guy refused to do what ever it took for HIS situation to care for the instrument. We repaired it again at no-charge to the client but I also subjected him to a conversation about his end of the deal and what's expected of him. He was informed in writing that we will no longer fix his instrument at no charge if the damage results from his negligence. It's a very unpleasant thing to have to do, at least for me it is but my back ground has decades of defending the bottom line in it so I have to protect the business too....

We are also one of the first lines of defense for Martin and Taylor against warranty claims that result from client abuse....

On one hand the bad weather is a boon for us but on the other hand for some of us who secretly believe that our "real" clients are actually the instruments it's pretty sad to see....

Lastly for now when I started building I was absolutely sure that I would never endeavor to sell my creations.... Of course this all changed... and I ended up selling but never building on a commission basis.

I'm bringing this up because if I had taken the position that my creations are just for me and that this somehow permitted me to have a lower standard of diligence in respect to RH it would have resulted in me being grossly irresponsible and negligent in not using best practices and then selling to the community.... As such you can't actually know, or at least I couldn't where my stuff would end up. This is yet another reason why doing what ever it takes where ever you are to get RH under control is a very good idea.

That's exactly the issue in Florida except that it isn't just in the summer. A dehumidifier is an OK solution, meaning it will do the job, but the heat can make the space unworkable.

Hesh is right on. It really is the most important thing to have in your shop. I just spent a good deal of money on spray foaming my new building. That sucker is gonna be tight and strictly controlled. Just this year I had a guitar come back to me that was dried out pretty good. This winter has been hard in these parts. I made a new saddle for this guitar and hope it doesn't come back this summer. I've always tried to work at 45%.

Just got to work and thught I would share some pics of how we deal with RH when it's winter here in Michigan.

Below are some pics that I took with the IPhone so they are not great and completely unedited because I am lazy....

In our tool room Dave built a utility closet complete with air filtration to house our shop-made humidifier and one of our air conditioners.

The shop-made humidifier is pretty brilliant and works better than any humidifier that I have ever used and I have used many of them. Prior to this one we had a commercial unit that was rated at 1,800 square feet. Our shop is around 1,000 square feet and the commercial unit could not handle it or even close....

We also have a commercial April Air plumbed into the wall complete with humidistat. The shop-made unit is also automatic and completely plumbed in as well so no schlepping water required.

With what we have we can maintain over 50% at -14F outside - no problem. It's super important for us too in so much as if any client property cracked while in our charge it would be completely aweful to all concerned.

This is also an example of someone, Dave going to a lot of trouble to get it right.

The inexpensive weather station pictured is periodically checked against a wet bulb test to make sure that it's accurate.

People often refuse to listen. I had a customer in today to pick up a guitar that was in for a top crack repair. I hydrated the guitar, repaired the crack, and gave him the lecture about how important RH is. I showed him my 5 gallon humidifier and my calibrated digital hygrometers. He said he would think about it, and then carried the guitar, with no case, out into snow and 22 degree temps.

I do manage to make an impression on many of my customers, but few of them really take the advice to heart and do more than make a cursory attempt to maintain RH for their guitar.

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It will probably be alright.

This works pretty well off the bathroom sink.

I was told to reduce the humidity of my work area, but near Brisbane this summer 90% is typical. With Aircon it reduces to about 60%. In winter it reduces to 50% but 40 won't happen. The problem would be even if I can reduce it to 40% as soon as the guitar leaves it would be in high humidity.. Then the states south of here it is dryer.