Case Humidity Question

Rich Cohen

Senior Member
Joined
Nov 22, 2015
Messages
3,145
Reaction score
2,274
Location
Charlottesville, VA
I recently acquired several vintage arch tops in their original cases. I recently went overseas for six weeks, and placed boveda 49% packs, two in each case, one in the head stock area, the other just near the upper bout. After returning, this past Friday, I noticed that the packs in the older cases had already "timed out" in that the material inside the packs had nearly crystallized over those six weeks; but only in the older cases. So, I assume it's a factor of the cases being dried out, as well as less hermetically sealed. Boveda's website discusses how one needs to "season" a case. In one instance I have a 1934 Epiphone Royal arch top (walnut) in its original case. I wonder if that case will ever allow a 45% humidity situation during winter to develop, or should I just look for a new case to protect it more efficiently? Same in the case of my 1954 Epiphone Zephyr Regent and 1957 Guild X-375B.

Thanks,
Rich
 

gjmalcyon

Senior Member
Gold Supporting
Joined
Feb 6, 2011
Messages
4,181
Reaction score
2,419
Location
Gloucester County, NJ
Guild Total
13
Drawing an analogy with my cigar humidors - those are seasoned before their first use by dampening the interior wood with water or with a sponge in a bowl, closing the lid, and letting them sit for a week.

Guitar cases are probably less airtight than cigar humidors so any seasoning you do would be shorter lived. I suspect that if you keep up with changing out the Boveda packs, you'll eventually arrive at equilibrium.

That said, I cannot go more than about three weeks in the winter without replenishing my Oasis case humidifiers.

You'll need a hygrometer to see what is going on inside the case - that might be a worthwhile investment to protect your vintage instruments. Here's one from Amazon I use in my humidors.

Finally, Boveda packs can be recharged - I have them in the headstock end of most of my cases as a little extra insurance. I've put them through multiple recharge cycles. Here's a YouTube video on how.
 

guitarslinger

Member
Joined
Aug 6, 2008
Messages
794
Reaction score
90
Location
Mayberry
Important to let that case season naturally. I made the woeful mistake of taking a very slightly damp cloth and wiping the interior of my case to hurry that process. I thought it had worked like a charm as once it was completely dry the interior of my cases were steady at 47%. Unfortunately, I began to see some transfer of the water soluable glue that holds the plush lining in place on my guitars. It wipes right off with a damp rag, but, it's highly disconcerting. This was on almost all of the NS and newer Guild cases. Didn't seem to affect older and other case brands.
 

Cougar

Enlightened Member
Joined
Nov 28, 2015
Messages
5,320
Reaction score
3,015
Location
North Idaho
Guild Total
5
Guitar cases are probably less airtight than cigar humidors....

Yes, and some cases are less airtight than other cases. I just use a few damp half sponges in a baggie punched with holes, with a $5 incubator hygrometer in each case. Keep the case closed when playing the guitar....
 

JohnW63

Enlightened Member
Joined
Dec 11, 2012
Messages
6,293
Reaction score
2,217
Location
Southern California
Guild Total
4
I quick and dirty fix might be to put the whole thing in a couple of large garbage bags and tape the two together to form a sealed cover over the whole case. The other thing you can try is other types of humidifiers. The gel beads can replace the sponges in the home made soap holder style, or using PVA sponge to get a longer time between wetting them down.

Water beads:
https://www.amazon.com/dp/B0177B70BQ/ref=psdc_166060011_t3_B0050ZNWYG

Probably a VERY LONG supply in this quantity. Just make sure the holes in the soap box are smaller then the beads in their dry form. I have read they last a long time. ( Good for 6 week trips )

PVA Sponge:
https://www.amazon.com/SAUGWUNDER-A...TF8&qid=1550463564&sr=8-4&keywords=PVA+sponge

The brick of PVA I bought at Amazon is no longer available, so the above link is as close to looking like it as any. PVA is VERY dense. Not squishy at all, until you let it soak in water for a while. Once flexible, it absorbs water well. If it dries out completely, it is stiff and hard again. Some of the " Hang by the strings " box guitar humidifiers use PVA sponge. I did some sponge testing and found that PVA does last a lot longer than a kitchen type sponge, but it doesn't have the big spike of humidity.
 

Rich Cohen

Senior Member
Joined
Nov 22, 2015
Messages
3,145
Reaction score
2,274
Location
Charlottesville, VA
I suspect a case from 1934, 1954 or 1957, where the lining is very thin compared to the plush liners we're used do, plus the materials out of which the cases were made is thinner and more porous, you're never going to get the sort of seal outside to inside that creates the best conditions. Thus the solution for humidifying such cases has to be different and more aggressive I should think. I wonder if it's possible to ever "season" such old cases to the point where they don't suck the moisture out of packets like the Boveda-s at a more rapid rate.
 
Last edited:

chazmo

Super Moderator
Joined
Nov 7, 2007
Messages
25,465
Reaction score
7,123
Location
Central Massachusetts
Rich, it's super great that you're making the effort to keep your axes properly humidified in winter. I applaud your actions because I can tell you first hand that you don't want to damage them yourself, especially since you're educated on the subject and understand the problems of humidity.

So, six weeks is too long to leave pretty much any of these humidification systems without attention. Bottom line is that you need to have someone help out on a bi-weekly basis (minimum) if you can. Or, you need to find a way to keep the instruments in a humidity controlled environment while you're away.

In practice, I really doubt you'd have any trouble develop after only six weeks, but I wouldn't take that chance either.

As for your actual question, the cases aren't meant to be sealed from the environment. They only really protect your axe from extreme swings. In a dry room, the case air will dry out; in a wet room, the opposite. Just not as quickly as the room can change. The same applies to temperature.
 

richardp69

Enlightened Member
Gold Supporting
Joined
Aug 11, 2009
Messages
6,007
Reaction score
5,965
Location
Barton City, Michigan
I'm likely very much in the minority here but that's o.k. I've never gotten comfortable leaving a humidifier inside any of my cases, I've just never done it. I am home nearly 100% of the time and do have a really good room humidifier that keeps my guitar rooms at 40% to 50% humidity. I'm not saying I'll never have a problem but thus far I have not. I think I'd have to revisit that if I had to leave the house for extended periods of time.
 
Top