This humidification system contains packs that consist of:
- A saturated solution of some salt in water (plus maybe some gelling agent)...
- ... inside a vapor-permeable but water-impermeable covering.
The packs fit inside nylon bags that fit into the guitar case and into the guitar itself.
The system is constructed to maintain approximately 50% humidity in a sealed vessel, such as a guitar case. If it's more humid than that, water vapor will be absorbed by the pack. If it's less humid than that, the pack will give up water into the vessel, thus humidifying it.
In a dry environment (such as an overheated city apartment), the packs don't last very long, because their capacity for water is not very high. Once they've given up all their water to the atmosphere in the guitar case, that atmosphere can't be humidified further, because there's no more water to release.
The problem is that the guitar case isn't really a sealed vessel. Even if you don't open it, air leaks in and out, so you can expect the guitar to dry out after, say, a month, even if you don't open the case. Hard-shell cases are better sealed than soft ones (and gig bags are worst), but on the other hand, if you use the guitar often, you will be losing your humid air to the dry atmosphere every time you take the guitar out, so you're damned if you do and damned if you don't.
The instructions that come with the system say to replace a pack with a new one when it dries out, but they're expensive. So here's how to regenerate these packs.
By the way, I've only done this once so far. I'll update this page with reports of my experiences. I take no responsibility for damage to your guitar if things go wrong, but if things go wrong for me in any way, I will certainly report it here.
Step 1: The Ingredients
From left to right:
- A crinkly dried out humidification pack from the humidifier system.
- A dry glass
- Lid to a Tupperware or other tightly sealable container
- That Tupperware or other tightly sealable container that the aforesaid lid fits
• There is about an inch of water in the container.
• The container is tall enough so that there is air space above the glass when sealed.
Step 2: The Assembly
- Place the crinkly old pack into the glass
- Place the glass into the Tupperware (or other tightly sealable container) that has water at the bottom
- Seal the container.
Step 3: Wait...
- Put the assembly on a shelf or in a cabinet where nobody's going to knock it over.
- Wait a week; a few days is actually probably enough.
Step 4: Unpack
- Open the tightly sealed container.
- Remove the humidification pack.
• It should now feel like the contents are liquid, as it did (or should have!) when it was new.
Step 5: Use!
- Place the newly humidified pack back into the nylon bag that you originally took it out of.
- Place the nylon bag it its place in the guitar case.
Step 6: Repeat As Necessary
I don't know how many times you can do this without limiting the capacity of the pack, but it should be at least a few. Even if it only works once, you've halved the cost of buying new packs each time.