Official Luthiers Forum!

For those who are new to guitar building like myself and not looking to spend a great deal on what is currently a hobby, I found this hygrometer on walmart.com for $3.98. Granted it's meant for cooking, but its "comfort zone" looks like the same "comfort zone" for guitar building.

Enjoy.

http://www.walmart.com/ip/Sunbeam-SHG50 ... r/15135864

_________________
Adam

Just got one from amazon for 5.50 includin shippin has alarm , time temp an humidity,

I'll only say this. Check them with a wet-dry thermometer system. They are likely off by anywhere from 10 to 30%.

_________________
Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Can this one be calibrated? I suppose if you had a few of these and they all moved the same, you could add marks on the cover to indicate where you want your shop range to be. . .

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

I read once that using those to keep track of humidity in your shop is akin to taking marriage counseling advice from a magic 8 ball.

Granted, I admit to having one like that in my shop, but I do use a wet/dry bulb to check accuracy from time to time.

Dave

I compared a number of these vs. 2 calibrated transmitters... the Caliber III was the only low $ one that was accurate within 5%. It's great between 40% and 60%, but it reports a lot lower than actual below ~35%.

_________________
David Malicky

Ok, guys, you got me. So, apart from going ridiculously cheap, I do want to make quality work. I live in Tulsa--next to the Arkansas river, as in within two miles. What is a good hygrometer that I can trust that doesn't cost much? I mean, yeah, over the long haul it's not a big investment, but still, I'm a little cheap.

_________________
Adam

Yo carl I know your area it is pretty humid, as here in KC. The humidity if uncontrolled wreaks havoc on my guitar woods if not monitored properly. My 2 cents, get a really good hygrometer and get a cheapie one that you can calibrate to align with good one .I keep my3 meters in 3 places main floor, garage, and bsmt.

No problem. Make your own psychrometer. All you need is:

1. a thermometer
2. this online calculator
3. to extrapolate the actual atmospheric pressure from the meteo data you'll find on the website of your nearest airport or aerodrome to the pressure at the altitude above sea level your shop is located.
4. to make sure you do the measurement while there is an even temperature in your shop and no great air circulation (or you'll probably not measure two times "the same air" when using only one thermometer for dry- and wet bulb temperature

This is a list which will help to interpolate atmospheric pressure levels at different altitudes indicated in meters above sea level (with normal pressure of 1013mbar at 0m).

Just go linear when figuring out your actual "right" atmospheric pressure using the data of the nearest airport and this table. It will be slightly wrong, but still good enough for our purpose.

The wet gauze wrapped around the bulb is important. If you use one that does not hold the water very well (shirt material etc.) you'll need a bit more material to hold enough water, which will result in a longer slinging time needed. Using T-shirt material I end up slinging the thermometer for 2 1/2 to 3 minutes till the temperature does not drop any more. When determining this point a digital thermometer really shines and you'll find that the 10 extra bucks were well spent.

Costs will be somewhere between 2 $ and max. 15 $ for an analogue or digital thermometer, plus a nail, plus an eye screw, etc.
When working very carefully precision will be better than +/- 3% even when using the cheapest thermometer you can find, respectively better than +/- 1.5% when using a decent digital thermometer and having the nearest airport within a few kilometres or miles, or even using a mountaineer's altimeter/barometer (which is what as I have - but that's not cheap anymore if you don't have it anyway).

I have written down the whole detailed story in Spanish, this is the link to the terrible google-translation (I believe you'll still get the main points I explain there, and you'll have a good laugh in any case - if an an important portion of the automatic translation is not understandable at all, learn Spanish ...or just ask me ).

Finally, here the analogue 2 $ thermometer version:

Click on picture to enlarge

And the digital 10 or 12 $ thermometer version:

Click on picture to enlarge

I hope this helps you save some $$$.

Cheers,

Here's a picture of my humidity stick. No idea how accurate or consistent it is, but the only time I've seen it curve more than that was last night. TV says we're round 7% r.h.. I haven't checked with wed dry yet, but it still seems like it might be time to move the guitars to the basement.

Mike

_________________
Mike Lindstrom

Ok, Markus: wow. Lot of good info there, but that seems like a bit of extra work.

Mike: That is a pretty innovative idea. I could see planing down an old stable piece of wood and letting it hang in my work area . . . of course, once it shifted everything else in the work area might've shifted too . . . oh well, I'll loosen the dusty purse strings and drop $20 bucks a decent hygrometer I suppose. Thanks guys.

Ernie: KC, my brother lives in Raymore. I love KC. Beautiful weather.

_________________
Adam

As mentioned, the Caliber III is the only good low $ one I know of. Just don't rely on it below ~35%.
http://www.amazon.com/Western-Humidor-C ... B0007W1EA6

_________________
David Malicky

Two things. First, it's not my idea. I got it from someone else here. Second, it's not just a piece of wood. It's two scraps of spruce top glued together, one cross grain, one long grain. It quite sensitive and responsive. It tells me when someone gets out of the shower, or when I'm boiling pasta. But as I said, I have no idea how consistent it is. I mostly use it as a quick easy visual about what's going on. I know if it's over to the humid side, I shouldn't even think about going downstairs to do any gluing.

I really ought to tape a backing sheet to mark on and see if it can be calibrated.

Mike

_________________
Mike Lindstrom

adam I am next door to your bro way on the south west side of lee/s summit abt 5 mi away from raymore . Your welcome to stop by when in town.

I have a similar one:

Click on the picture to see the (spanish) blog entry, use the google translate option at the bottom of that page if you are eager to read that stuff in something similar to English.

... and I think it is pretty consistent, much better than any "cheap" hygrometer other than a cheap psychrometer. I had done comparisons with a cheap-and-everytime-recalibrated hygrometer throughout an year or so and the wooden hygrometer seemed to be always right compared to the freshly re-calibrated cheapo.

However, a few weeks ago I decided to modify the wooden hygrometer a bit, so all the previous measurements don't serve anymore for future comparisons. I took this as an opportunity to start over with comparisons, but this time with my psychrometer. Again, as far as I can tell after these few weeks it seems to be consistent. I stored the records on my PC and uploaded them right now to the Internet here in case someone should be interested in (sorry, each picture weighs 1.5 MB - initially I did not think of publishing them but thought of a quick & dirty data collection just for me).

A few days back after a couple of rainy days I had 40% RH but for some reason forgot to take a picture of the wooden hygrometer. However, now RH is back to 29% and the wooden hygrometer indicates just what it should on its "scale" which so far are only the grain lines of the base plate.

The wood I used is abies alba, here we call it "Weisstanne" which literally translated to English would be "white spruce" or "white fir", but i thing usually it's called "silver fir". I used this wood because I had scraps of it laying around. I don't think that, regarding consistency it matters which kind of conifer or even any wood one uses for building a hygrometer.

I glued up the short indicator with HHG, and the long indicator with Titebond. I could not see any difference so far, although I have to admit that I don't look too much at the short one. The nice thing of the two indicators is that when they start to "intersect" (they are now narrower than the strip in the first picture above) I know from a distance that humidity is dropping below ca. 30% which is kind of alarming for some older instruments I own (that's the critical RH when they must stay in their case).

Just seeing how much the wood warps really gives me something to think about. Thanks, guys.

_________________
Adam

I bought my hygrometer/thermometer from http://www.burgessviolins.com/products.html. He calibrates them and guarantees accuracy all for 30$. I talked to him he is a very nice guy, I highly recommend his product.

Robbie

Now, don't go freaky on me here, folks, because I'm not making any claims as to the accuracy of this thing. I found the directions for making it and "calibrating" it in FINE WOODWORKING many years ago. I carried the unglued wooden strips in the back seat of my car one winter until the weather service told me the RH was 50%. Then I glued them together with epoxy to minimize glue soaking the wood. The end of the stick is fastened in a dowel that can pivot in a hole and be locked in place when desired. The curved beam was a slip fit into the vertical post. Everything got placed in a clear-lidded sealed container with a bowl of water and checked daily until the bilateral strip quit moving in one direction. I marked that position on the beam. It was practically raining inside the chamber--lots of water drops condensed inside the lid. Then the wood parts were placed in a sealed container with an open bowl of desiccant (I think I used calcium chloride snow melt, but can't remember for sure) until the strip moved as far is it could in the other direction. I marked that position. I doubt that it ever got to a true "0" in there. These two extremes were labeled "0" and "100" on the curved beam--although they might not truly be those values. I used dividers to find "50" and even increments on either side. Then centered the curved beam, glued it, and put everything back into the dry chamber. When the strip stabilized, I set it to point to "0" and locked the dowel there. Then hung it on the shop wall. It is remarkably sensitive, and will move in either direction pretty quickly. It was fun, and I use it as a rough indicator. When it's pointing to "50", the stick is as straight as the evening I glued it up. I just shot this pic to illustrate and as you can see, I won't be doing any cross grain glue ups for a while......