Humidity ... again

[Guitar Cowboy]

 I have had a couple of my guitars  closed in their cases with humidipaks  for  over a week and I cant get the  humidity down below about 61 %. They claim that these  provide two-way  humidity control and will maintain your case at 47 %. The Taylor humidity spec sheets also say this .  I don't think this is exactly correct. I don't think they have any ability to  lower the humidity unless they are hard and crunchy . So you cant just expect your humidity  to be maintained correctly by just buying these   and  throwing them in  your case. They need to be in the  right "state". If they are hard and crunchy, they will remove humidity. If they are soft and fluid, they will provide humidity.  There is no "Magic " here that keeps the RH at 47%.

It looks like its time to swap them out for silica gel packs and  attack my cases with a hair dryer.

Any other thoughts on this out there?  Thanks

Steve

[timfitz63]

Your observations are almost certainly accurate.  The Humidipaks will absorb moisture to the extent that they are not already saturated.  New-from-the-package Humidipaks will absorb a bit of moisture, but not necessarily enough to bring the relative humidity into the target range; the manufacturer probably makes the assumption that the humidity level is already close to the target range, if not slightly dry.  So for environments where extra moisture absorption is a consideration, perhaps it's best to keep some 'crunchy' Humidipaks on hand.

[Guitar Cowboy]

So,  I did a little experiment last night. I emptied two of my  cases that had been reading about 62% RH and took a hair dryer to them  for about 15 minutes until my hygrometer read 35% RH.  I then cooled down the case  using the no-heat  switch on the hair dryer  and put my guitars back in for the night  along with  three small silica gel packs . By morning the HR was up to  53 - 55 %... somewhat better, but I was hoping to see 45-47%. I'll check again when I  get home from work and maybe repeat the process. The RH in my house has  been in the 62-65 % range with all the rain we have had lately. I ordered some larger (10 g) silica gel packs  that I'll start using  during the wet season instead of the humidipaks.  It was cold last night and we had the heat on for the first time this year , so it wont be long until I am fighting the battle in the other direction.

[Earl]

Just my opinion, but the "two-way" functionality is somewhat limited.  You are depending on a saline solution to absorb or dispense moisture beyond its natural equilibrium point.  If your packs are not crunchy and almost fully dried, their ability to absorb very much moisture is marginal.  If you are trying to dry the case's interior environment, then silica gel desiccant packs are the right tool for the job.  It is good to remember that the case itself, the padding, and the plush lining are reservoirs for moisture too.  That works in your favor as things dry out, mitigating the speed of change.

Personally I would not bother trying to maintain exactly 47% RH -- plus/minus 5% is plenty good enough for the health of your guitars.  It is easy to become compulsive about humidity control.  In the summer our house stays at about 45-55% RH, and I don't bother doing anything until we drop below 40% for more than a couple of days, either from peak season AC, or from heating as we have begun now.  It was 39° here this morning, but 67° now.

[DO18]

I have struggled with high humidity, but I live in SE Asia about 14 degrees above the equator.   I have done the silica packs and hair dryer treatment and not experienced much success. The RH here is typically around 80% and the temps are between 80 & 90.

I purchased Boveda 49% High Absorption formula packs and have been successful in bringing the RH in my three guitar cases down to 52% consistently.   I have two in the soundhole,  two at the heel and one at the headstock.

I had used 10g silica packs and 10 5g packs stuck to two strips of gaffer tape and wasn't able to get things lower than 60%.

I'm sold on Boveda!

[JuanValdez]

It's too dry where I am to worry about guitars being too damp, I have just the opposite problem. However, occasional rains will bump up the humidity and I do worry about my firearms rusting. My storage options swing with the RH more easily than the inside of my guitar cases do. A lifetime of consuming stuff has left me with a pretty serious collection of de-humidification paks that come in product packaging.  I toss em in with things I worry about rusting and they seem to do well.  I regularly dry em out in the oven on low heat on a cookie sheet and toss em back in with my stuff in want to keep dry.  So far, so good. I cannot imagine why the same thing wouldn't work in a guitar case.