Official Luthiers Forum!

Okay this is my first post so be kind.
I am going to ask a question by using a back story so here goes.

I first became interested in building guitars about 15 years ago. I had just graduated from college and was playing for churches and youth camps on a regular basis and also loved woodworking, so the two seemed to lead to something. A buddy of mine and I were very interested in learning more about lutherie and although I don't remember how we got hooked up with him, the next thing we knew we ended up spending the day in the shop of Kevin Ryan. He invited us to come and take a look and spend the day watching, learning and even drilling some bridges on one of the many ingenious jigs he had that even complete novices could not screw up.

We spent that day and a few others watching a master. We were even invited to his house several times for living room concerts. We saw Laurence Juber and Peter Finger play in Kevin and his wife's living room, what an awesome way to drum up word of mouth. And until just recently I did not really realize how lucky I was to be a part of this.

Flash forward 15 years.

Now that I have been a member here and have 'lurked' for a while I am having a problem reckoning what I remember, and what I have been learning here and need advice, clarification, help. At the time when we were learning from Kevin in his shop, his shop was a one car garage. And when he worked the door was usually wide open! It was in Westminster,CA about 60 miles from where I live, and I also only have a garage in which to set up shop.

I know that there is really not a lot of humidity where i live a great majority of the time, regardless of the season, and the temperature is relatively stable when compared to places that have real summer and winter, but do I still need to be hugely concerned with keeping the garage door shut, and get a humidifier and dehumidifier and an a/c in my garage?

Kevin was charging $3500 for a mission then and they were made in his garage.

Thanks in advance.

Dustin Ellis

Hi Dustin and welcome to the OLF!

Great story about your introduction to Kevin Ryan and many of us would kill to have had the opportunity that you and your friend had to hang out with Kevin.

Step one in understanding humidity, relative humidity (RH) for wooden stringed instrument construction is to understand that if you ignore best practices RH issues WILL bite you and often at the most inopportune time.... We see many posts from folks who's tops turn inside out or they hear a loud crack at 3:00 AM and it's coming from the direction of their shops....

What you will need to do will depend on where you live and the climate that you have to deal with as well as where your shop is located, how well it is sealed/insulated etc. Not that there are any industry standards for RH and temp but a 42-48% RH range and a temp of 70F+ are good numbers for building guitars. Martin and other fact*ries use similar numbers.

Understand in advance that all digital hygrometers are inherently inaccurate and not suitable for our purposes unless used in conjunction with a method of determining RH accurately and subsequently calibrating the hygrometer, either mentally by just noting the error, or physically for some of the better mechanical hygrometers that can be calibrated.

Do a search on wet-bulb tests and sling psychrometers and you will find a lot of information here and on the web. Either method is an inexpensive and reliable way to determine the actual RH. Once you know this you can look at your digital or mechanical hygrometers and start to understand what their numbers really translate into against a "standard" or the wet-bulb test.

I live in Michigan and in the winter I run a humidifier in my shop (and home too since they share a forced air heating system) and in the summer I am running a dehumidifier. Needless to say I am always schlepping water and hate it....

Temp for building is more a matter of builder comfort, considering the temps that the glues that we use need to perform, and understanding that many/most dehumidifiers won't work below 70F.

In a nut shell equipping yourself to do wet-bulb tests will serve you well and will help you understand that your RH may swing a great deal in the course of a single day.... It's a moving target so-to-speak but you can get control of your RH once you understand what needs to be done to your own shop area to make it stable.

Even though Kevin may have had the garage door open I suspect that he watched the RH for opportune times for cross grain gluing and other operations that can be impacted by RH swings. His climate may have provided numbers such as I noted above more frequently than my area which never.... has RH numbers in the stated range for more than a day or so....

Welcome aboard!

Dustin, we all know that wood responds to changes in RH by moving. That movement can destroy an instrument in short order.

If your homemade guitars will stay at your own home and the RH is pretty stable, the guitar will experience relatively small movement. Therefore, no amendments need be made in your build environment. If your guitars are built at 15% RH and then shipped to Louisiana, or the reverse, there are going to be problems.

The numbers typically quoted is a workshop RH range suited for the fat part of the bell curve for typical homes, i.e. 40-45% RH. If that is where your guitars will have to live, then you should take steps to store your wood and build your guitars accordingly.

So, there are no absolute answers about the range in which we all should be building guitars. Put simply, you should build guitars in the environment in which your instruments will have to live out their lives - difficult if that environment is unpredictable - in which case you shoot for the middle of the range and possibly toward the dry side since low humidity seems to create the most dramatic problems.

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"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

Hi Dustin,

I build out of my garage too. Up in Simi, you'll probably need to close the garage and use a humidifier at some point during the summer and whenever the Santa Ana's blow. You can get a cheap humidistat for about $15. It may not be dead accurate, but it'll at least tell you know the humidity +/- a few percent.

The better insulated your garage is, the easier life will be. Mine's not insulated at all, so I sometimes have to glue-up in the house. You may need to do the same if it gets crazy hot and dry. But most of the year, I think you'll be fine.

Welcome to the OLF and enjoy your building!

Flori

Hesh,
On this subject, I'm currently using a cheap homemade wet/dry hygrometer. Do you think these are accurate? It is a pain to have to blow forced air across the wet bulb for ten minutes every time I want to know the RH and also I get cross-eyed trying to line up the columns on the chart. Other than that, I like it just fine. But anyway, if I decide to buy a pricey Abbeon later can it be calibrated with my homemade ReneCo. instrument rather than sending it to the mfg. for calibrating?
It would seem not since the Abbeon is about $175. and mine cost about $3.97. What do you think?

René

So Hesh, are you saying that the problem with digital hygrometers is just that they aren't well calibrated, but they are consistent? So once they've been checked, you're ok to use them with a correction factor?

Thanks
Mike

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Mike Lindstrom

A cheap, homemade wet/dry should be just about as accurate as a store bought wet/dry. If you are relatively obsessed with humidity control, you should have a fan running all the time, so you can just hang the bulb in front of the fan.

Not obsessed, just want a reliable way to know what the RH is at any given time during the day. I don't want another crack in my top.