Black mold in soundhole from leaky humidifier?

[KFP55]

I live in New England and have been attempting to keep my collection protected from the dry air this winter. I’ve been using the soundhole humidifiers that sit between the 3rd & 4th strings. When I checked to see about re-wetting the sponges yesterday, 3 were still moist and the humidity right at 50%. Unfortunately the 4th was bone dry....and there were some black spots in the soundhole, particularly around the bracing. The ink on the signed label had run as well.

I wiped it out with a dry cloth and nothing changed. Then tried a mixture of distilled vinegar and water earlier today - looked as though that helped, but 30 minutes later it was actually worse.

Any idea what is going on and how to fix it? I mean - how is it possible that - at most - a few tablespoons of water caused mold in just a few days? Would you recommend taking it to a tech or just giving it a week or two in the dry air and letting it dry out completely?

Very frustrating situation, especially because I’m trying to do the right thing I caused the problem...

[WiseAxe]

Your post underscores the advantage of humidifying the room, instead of the inside of the case. Moisture + favorable temperature + darkness is the perfect combination of conditions for mold growth. Mold spores can lay dormant for years waiting for optimal conditions for growth.

Light is the enemy of mold. So is air movement. Lose the strings, lay a pad in the soundhole, put a jar lid or something small to hold a little bleach. Also try to get some light in there- an LED light would not generate the heat of other bulbs. Put your hygrometer in there to monitor RH and temp as well.

[Athens]

Sorry that you had a problem.

As infrequently as this happens it's precisely why I use the sponge in a soap dish and put it in the area under the head.

I hope it can be taken care of easily.

Keep us posted.

[Swamp Yankee]

The presence of drip marks on the label seem to me to be an indication that the sponges were far too wet. It's important to wring them out until they no longer drip before you put them back

The presence of mold seems to be an indication of humidity levels much higher than suggested. I doubt mold would grow at the 40% - 50% RH which is recommended.

Have you tested your hygrometers? I had one that read 8% lower. Getting a reading of 54% on that one would have meant the guitar was edging into mold territory.

[MikeBmusic]

As post above states- are you wringing out the sponge before putting it in the sponge holder? Sounds like you are not, and it was dripping down into the guitar.

[DenverSteve]

Originally Posted by Swamp Yankee

The presence of drip marks on the label seem to me to be an indication that the sponges were far too wet. It's important to wring them out until they no longer drip before you put them back

The presence of mold seems to be an indication of humidity levels much higher than suggested. I doubt mold would grow at the 40% - 50% RH which is recommended.

+1. FAR too much water in the Dampit. There have been way too many horror stories over the years about minor and catastrophic issues from placing humidification devices inside guitars to cause me to never place anything inside my guitars. I would think spraying the area with a bleach solution and leaving the guitar out to allow drying would do the trick but I would defer to a qualified luthier for confirmation.

[The Bard Rocks]

Originally Posted by WiseAxe

Moisture + favorable temperature + darkness is the perfect combination of conditions for mold growth. Mold spores can lay dormant for years waiting for optimal conditions for growth.

Light is the enemy of mold. So is air movement. Lose the strings, lay a pad in the soundhole, put a jar lid or something small to hold a little bleach. Also try to get some light in there- an LED light would not generate the heat of other bulbs. Put your hygrometer in there to monitor RH and temp as well.

The LED idea is a great one. IF you have an area of the home that is extra humid (bathroom? basement?) you could try that with a small fan added to blow into the soundhole.

There are products that will get rid of mold if the bleach does not do that for you (cut it with water and just wipe). You can get these products at Home Depot and places such as this.