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Well I was blissfully unaware of the humidity levels in my home where I was keeping my first set of zoot. I bought a cheap-o Harbor Freight wall clock that displays temp and humidity - when I took it out of the box it was showing a fair 55% or so... 5 minutes later it is showing 75%!? I don't get it. I live in the PNW where it seldom is "dry" but Doug O who lives near has a humidity gauge and his show was considerably lower.

I think the clock is fairly accurate too - I watched the RH plummet to around 30 in my car with the AC on coming back from the store.

Side note- It has been raining the past few days and we have had a bit of a roof leak issue (but it only went into the attic). Although today a new roof is being installed. Am I being paranoid about this humidity thing?     

_________________
Time is a great teacher, but unfortunately it kills all its pupils - Louis Hector Berlioz

Chansen / C hansen / C. Hansen / Christian Hansen - not a handle.

Christian

Chansen, I wouldnt put too much faith in a cheap humidity guage...they can be out by a huge amount. Get yourself a decent guage.


Cheers Martin

I bought a second (cheap) clock/temp/humidity unit from Woodcraft at the trade show last weekend.  It reads 10 points higher than the one I have had in the shop the last couple of years.  I'm inclined to believe my old humidity gauge, but now will have to go get another one (expensive?) to see what's going on.

BTW - my old gauge has always read in the 42% to 50% range, except when the grandson decided to mop the floor, which caused it to spike to about 70% for a day.

I had just assumed mine was correct, but I'm going to test it with the salt water and baggie just to make sure.

Thanks for bringing this thread up!

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Reguards,

Ken H

Well I'll probably get another brand of cheap-o this time and I'll have something to compare to at least. That Caliber III looks pretty good for just $20. Thanks for linking to that other thread- it helped.

Doug- 10 points higher on this new machine would read about what the weather report is saying. Tough call to figure out which one is correct.

 

_________________
Time is a great teacher, but unfortunately it kills all its pupils - Louis Hector Berlioz

Chansen / C hansen / C. Hansen / Christian Hansen - not a handle.

Christian

Christian - I'm not thinking I can rely too much on the weather report for humidity.  My shop is heated and fully insulated, which will affect the RH from inside to outside. 

I stopped at a cigar store on the way home tonight.  They had about 8 different hygrometers in the case and no 2 read the same.  Most were within 3 or 4 percentage points of each other, but overall there was almost 20 points from high to low reading - all in the same display case in the store.

Looks like the only way to know for sure is to do the baggie thing.

if you want to really know, get a psychrometer. they are often available on ebay for relatively few dollars. it is what is used to calibrate the expensive analogue hygrometers.

i've been using a digitals from radio shack for about 10 years, both for room and incase use. these sold for about $25.

not so long ago i dropped one and it expired. replaced with a real el cheapo from walmart, less than $8.00, which works just as well in side by side comparison, always within a point or two. as with all digital technology the cost/performance ration has been getting better for the consumer with the passage of time.

I live in the PNW too - where I lived humidity spiked up to 86% the other day, but usually its lower inside the home.
Cheers
charliewood

Last year I bought 2 digital hygrometers from Stew-Mac. They agreed
with each other perfectly and disagreed with my existing hygometer by a
lot. As a consequence I started adding a lot of humidity to my shop to get
the Stew-Macs up to the low 40s. To make a long painful story shorter,
they turned out to be reading 15 to 20 points too low. I had to replace a
soundboard on a guitar that had been built during the time the humidity
was too high.

I learned a lot about hygrometer calibration, and here is the bottom line: I
would not buy ANY hygrometer that can not be calibrated. I would not
assume that if 2 hygrometers in a store or in your shop agree with each
other that that means anything, if they have not been tested. I would not
have a digital hygrometer in my shop. Stew-Mac ignored my concerns
about this issue - did not even offer my money back. You must regularly
verify the accuracy of hygrometers with either the salt test or a sling
psycrometer or similar wet bulb/dry bulb type of device. If you use the
salt test, use double bags, a constant temperature, and preferably
distilled water.

There are many stories of digital hygrometers wandering WAY off after
various periods of time.

Good luck,
Brook

A few other comments -

The local weather report for your area is not a reliable indicator of the level
in a building. Putting aside variations in outside RH, which can be quite a lot
within the area of the nearest weather reporting station, if your shop is
warmer than the outside, then the shop RH will be lower than outside RH,
not considering the affects of hvac systems. Conversely, if the shop is
cooler than the outside, then the indoor RH will be higher. 2 shops in the
same area can have considerably different RH levels depending on heating/
cooling, air tightness, local micro-climates, etc.

Thanks Brook, I will keep these things in mind. There are so many aspects to guitar building that I never realized I would be concerned with. Very interesting stuff I'm glad I'm finding out now instead of later.
Christian

_________________
Time is a great teacher, but unfortunately it kills all its pupils - Louis Hector Berlioz

Chansen / C hansen / C. Hansen / Christian Hansen - not a handle.

Christian

[QUOTE=BrookM]Conversely, if the shop is
cooler than the outside, then the indoor RH will be higher.[/QUOTE]
It should be mentioned, though, that if the shop is cooler due to air conditioning, the RH will likely be lower than the outside. AC units dehumidify--some better than others.