Guitar Humidifing Question

rcsnydley
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Tue Dec 29, 2009 10:52 am

I have a solid top guitar and know that now that the dry Winter months are here I need to humidify it.

However, my daughter has a plywood top guitar and I heard they do not need to be humidified. I am looking for some insight on this and any help I can get would be greatly appreciated.


haoli25
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Tue Dec 29, 2009 11:48 am

Ric, the construction of plywood is what makes it so stable. The wood grain of each veneer sheet are alternately placed 90 degrees to the previous sheet. This 'cross-grain' construction pattern, the high strength adhesive used, and the extreme pressure used to press the plywood 'sandwich' together prevent the contraction and expansion that normal single grain wood experiences during temperature and humidity extremes.



Bill


BigBear
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Tue Dec 29, 2009 1:49 pm

haoli25 wrote:
Ric, the construction of plywood is what makes it so stable. The wood grain of each veneer sheet are alternately placed 90 degrees to the previous sheet. This 'cross-grain' construction pattern, the high strength adhesive used, and the extreme pressure used to press the plywood 'sandwich' together prevent the contraction and expansion that normal single grain wood experiences during temperature and humidity extremes.



Bill

Bill- Good answer from an electrical junkie! lol! :laugh:


Ric- this question went around the forum a month or two ago but I think the short answer is wood is most susceptible to changes in humidity versus just the relative humidity in your home.

Most guitar woods are sawn at very low moisture contents, usually less than 9%. Once dried this low, they don't absorb much moisture ever again as the cells seem to close up. So once tonewoods get this dry, having low humidity in your house isn't going to affect the guitar much.

The optimal humidity for guitars is 40-60%. Really low humidity would be 20%. So if your guitar starts at 9% and your house is bone-dry at 15-20% in the winter, your house is still contributing moisture than the guitar!

That little bit of common sense comes with a caveat. Some woods, notably mahogany, seem to be really sensitive to cracking or splitting. I suspect this is caused by where it comes from (higher humidity), it's density and it's probably sawn at higher moisture contents. Sapele is another wood that seems to have problems as well.

So I don't think it would hurt to keep a humidifier in your guitar during the winter but I'm not totally convinced it's necessary either. The science of it doesn't work for me.

Cheers! :cheer:


dennisg
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Tue Dec 29, 2009 2:36 pm

Bear,

Yeah, I remember the thread about humidification from about two months ago. Very interesting.

If, as you say, wood is less affected by a specific relative humidity than it is by changes in humidity, it seems to me that it would make the most sense to humidify it all year long. If you get the right type of humidifier, it will pull humidity out of the air during excessively humid times, and release humidity during particularly dry times. With that system, my guitar stays between 45 and 52 percent. The downside, of course, is that you have to keep the guitar in the case, but I consider that a small price to pay.

- Dennis


goldleaf
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Tue Dec 29, 2009 6:57 pm

Dennis, what type of humidification system do you use and what do you use to measure the humidity in your cases. I have 5 acoustics in cases that I should invest in keeping properly humidified. Just interested in what you chose and if you are satisfied with your humidity equipment. Gary

Bear, does plywood fall under the catagory of a tonewood?? Gary


dennisg
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Tue Dec 29, 2009 8:08 pm

Gary,

I use the HumidiPak system from Planet Waves. It's like a tiny set of saddlebags into which you slip two little humidity bladders. Then you slip the saddlebags between the strings into the soundhole. It also includes another, single pack that goes under the neck. What I like about the system is that you're not screwing around with water, so it'll never drip and discolor the inside of your guitar. As for the hygrometer, I think it's a Caliber III model that I bought on Amazon for about $15 U.S. It's not the kind of hygrometer you'd put on a wall, because it's so small. Works perfectly in a guitar case, though.

Regarding tone woods, Taylor is fond of telling people how they built an excellent-sounding guitar out of wood from a forklift pallet.

- Dennis


reiver
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Tue Dec 29, 2009 8:50 pm

dennisg wrote:
Regarding tone woods, Taylor is fond of telling people how they built an excellent-sounding guitar out of wood from a forklift pallet.

- Dennis
And Fylde make one from old whisky barrels, The Fylde Ariel Single Malt Image


Chasplaya
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Tue Dec 29, 2009 9:38 pm

dennisg wrote:
Gary,



Regarding tone woods, Taylor is fond of telling people how they built an excellent-sounding guitar out of wood from a forklift pallet.

- Dennis
And heres me thinking they (Taylors) were meant to be top end guitars, made from pallets, what is Bigbear thinking about lol!!

I just got a weather station for Xmas, main reason for wanting one was for the Hygrometer, I have the main station in the guitar room, as I had no idea what the humidity was in my house let alone the guitar room. Too early to say whether I have any issues to deal with, but i've read the saddlebag style humidifier dennis talks of is the deal to go for!


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