Less Humidity In An Open Case?

fpuhan · #1 03-07-2022, 04:42 PM

Yes, another post on humidity. Probably a never-ending topic for discussion.

Here's the issue that's baffling me. Picture this:

I have a humidifier. The built-in hygrometer is reading 54%. Four feet from the humidifier, I have a hygrometer reading 55%. Five feet from the humidifier I have still another hygrometer reading 53%.

Between the two hygrometers I have my Martin resting in its open Martin case, with a hygrometer placed below the neck on top of the accessory pocket. It's currently reading 41%.

All the hygrometers were calibrated recently, at the same time.

So, how can it be that I'm getting a more than 10% drop-off of humidity simply by virtue it's in the case?

It's not just now, either. I've placed the case in different locations in the room and I get the same type of results.

Normally I use the two-way HydroPaks (maintain version) in the case. One behind the headstock and two in the sound hole, but I was getting these kind of readings even with the case closed, so I thought I'd try this experiment. I wasn't expecting these results.

(The photo shows the nearest (4') and the in-case hygrometer)

I'm going swap hygrometers, but having done so before, expect the same odd results.

Any ideas?

warfrat73 · #2 03-07-2022, 07:15 PM

Try the same thing with a fan (gently) blowing into the case for a few minutes and see what happens. The equilibrium isn't going to instantly balance out.

Chipotle · #3 03-07-2022, 07:19 PM

Have you calibrated/compared the hygrometers before? Switch them and see if the one in the case still reads low when it's outside the case, and vice versa. Maybe it's just the hygrometer that's off. EDIT: I just noticed you said you did this already. If it really is the humidity in that micro-climate and not the hygrometers, it is kinda strange.

fpuhan · #4 03-07-2022, 07:47 PM

Quote:

Originally Posted by Chipotle

Have you calibrated/compared the hygrometers before? Switch them and see if the one in the case still reads low when it's outside the case, and vice versa. Maybe it's just the hygrometer that's off. EDIT: I just noticed you said you did this already. If it really is the humidity in that micro-climate and not the hygrometers, it is kinda strange.

This was the next step after I posted. I swapped the two hygrometers in the photo. An hour later, the outside hygrometer now reads 49% and the one in the case reads 46%. Better, and both within tolerance. The humidifier is reading 53% and the far hygrometer 52%.

It's almost as if I have a "Bermuda Triangle" where my guitar is placed. Or that it IS the Bermuda Triangle, as it really doesn't matter where I place it.

MikeBmusic · #5 03-08-2022, 07:49 AM

My guess is that your case itself is not as humidified as you thought - the wood is drier.

rollypolly · #6 03-08-2022, 10:02 AM

That is odd. I have the same case and mine reads higher humidity , and I haven't even soaked the humidifier that's inside in the weeks so it's probably dry and the case is doing its job. It's a newer case, only probably a year old.

Maybe you have an old case that has dried out and it needs to be humidified itself?

Also, I see you're in VA. I'm in NC and it's been very humid the past few days. It's been around 60% in the house and only 45% in the case. So our numbers are pretty similar.

In general, I wouldn't worry too much about it , especially in your geographic locale.

fpuhan · #7 03-08-2022, 11:31 AM

Quote:

Originally Posted by rollypolly

That is odd. I have the same case and mine reads higher humidity , and I haven't even soaked the humidifier that's inside in the weeks so it's probably dry and the case is doing its job. It's a newer case, only probably a year old.

Maybe you have an old case that has dried out and it needs to be humidified itself?

Well, it's a new guitar and case I bought from Maury's Music only three months ago. But tell me more about this "humidifier that's inside the case." The case is a Martin-branded TKL case made specifically for the guitar (DJr-10E). There wasn't any info on the case itself except for the warranty tag. But I did find a packet of what I thought might be a desiccant in the accessory pocket, and thought that might be the issue. Is that actually a humidifier? There is nothing on the packet itself that suggests it, and by feel, it's just filled with pellet-type material.

dnf777 · #8 03-08-2022, 11:48 AM

Despite advertising claims, none of the consumer grade devices are high-precision equipment. Id say +/- 10% is about as good as you can expect. Also, how did you calibrate them? (I have several, and take the average reading as the reference point). Not valid, but works in a pinch.

fpuhan · #9 03-08-2022, 12:06 PM

Quote:

Originally Posted by dnf777

Despite advertising claims, none of the consumer grade devices are high-precision equipment. Id say +/- 10% is about as good as you can expect. Also, how did you calibrate them? (I have several, and take the average reading as the reference point). Not valid, but works in a pinch.

I have a total of four hygrometers. One is built into the humidifier, so I don't have a calibration method for it. The others I use a combination of approximately a teaspoon of salt mixed with water into a paste. I then place it and the hygrometer into a sealed "capsule" (a Tupperware container) and let it sit for 10 minutes to an hour. Upon removal, the hygrometer reads 75%, which is the accurate reading for a calibrated device.

AcousticDreams · #10 03-08-2022, 12:32 PM

Well this is certainly a very interesting discussion.

I have my meter permanently attached in the same area as you do. I use a wrap around felt holder, made by Oasis and Velcro to attach my meter.

In my case, it is just the opposite. My humidity gauges on my tables read 36% for my room.
But my in case meter is reading 48% right now. I have left the lid open for approximately 5 minutes for it to completely stabilize.

The results from both your test and my test might possible suggest that humidity is dependent on its surroundings? That humidity can work more like a solid mass and in certain instances, can retain its position. In this case, I am saying that moisture becomes like a weight and is staying in place.

Think of it similarly to riding close behind a big truck and your car uses less effort to propel itself. The Truck is creating a air blocking field. Possibly the case lid, the channels & ridges of the case are also creating a block.

I am only hypothesizing of course. No conclusive evidence. But this does lead me to believe that this is a strong possibility. Humidity can act like a mass and if undisturbed(as the case protects it from wind movement) can remain in place.

I use only a sponge system. You are using Humidipaks which I believe absorb and release moisture. Mine only releases moisture. This might account for the exact opposite reading you and I are having.

Dbone · #11 03-08-2022, 06:30 PM

Quote:

Originally Posted by fpuhan

I have a total of four hygrometers. One is built into the humidifier, so I don't have a calibration method for it. The others I use a combination of approximately a teaspoon of salt mixed with water into a paste. I then place it and the hygrometer into a sealed "capsule" (a Tupperware container) and let it sit for 10 minutes to an hour. Upon removal, the hygrometer reads 75%, which is the accurate reading for a calibrated device.

Unfortunately that is not the most accurate way to be calibrating. You should be using Potassium Carbonate. You will find many posts on this forum about it if you search.

For your convenience here is a video on YouTube:

https://www.youtube.com/watch?v=dRUqPWOGtuI

Cheers

MikeBmusic · #12 03-09-2022, 08:19 AM

Quote:

Originally Posted by fpuhan

Well, it's a new guitar and case I bought from Maury's Music only three months ago. But tell me more about this "humidifier that's inside the case." The case is a Martin-branded TKL case made specifically for the guitar (DJr-10E). There wasn't any info on the case itself except for the warranty tag. But I did find a packet of what I thought might be a desiccant in the accessory pocket, and thought that might be the issue. Is that actually a humidifier? There is nothing on the packet itself that suggests it, and by feel, it's just filled with pellet-type material.

That is a desicant, to absorb moisture. Your case needs to be humidified!

TedBPhx · #13 03-09-2022, 10:03 AM

After much indecision over where to place a case hygrometer I decided that the level inside the guitar is what matters. Since I have Taylors I ordered two of those TaylorSense devices that replace the battery holders. Should be here tomorrow. Since I live in Phoenix my guitars live in their cases with humidipacks boosted by Oasis.

fpuhan · #14 03-09-2022, 10:09 AM

Quote:

Originally Posted by dnf777

Despite advertising claims, none of the consumer grade devices are high-precision equipment. Id say +/- 10% is about as good as you can expect. Also, how did you calibrate them? (I have several, and take the average reading as the reference point). Not valid, but works in a pinch.

Quote:

Originally Posted by MikeBmusic

That is a desicant, to absorb moisture. Your case needs to be humidified!

Okay, I can do that. But there does not appear to be a humidifier built into the case. A damp sponge in a ZipLoc bag with a hole or two in it for a couple of days ought to do it, right? Keep the guitar out of the case during the process to keep the case itself absorbing the moisture?