bob_mc
Oct-09-2020, 8:55am
I keep my gear together in a semi controlled environment in my basement. My mando goes sharp in the case whereas my flattop does not.
I am considering wrapping the case in a plastic bag; any risk to that?
In full disclosure its a lowly Rover RM35S; the top is laughably thick, which is a plus in my application playing with many, many, loud and louder instruments as it does not feedback as easily as previous instruments I have tried.
EdHanrahan
Oct-09-2020, 10:33am
... a lowly Rover RM35S ...
HA! That's my "sits next to the TV chair" instrument. When I first got it (cheap!) 10-12 year ago, it had sat with the bridge badly out of position, under full string pressure, for at least several months, maybe years. Thus, the top was fairly collapsed on one side. I figured that, at worst, it could be fun to see what makes it tick.
Inspection w/ a dental mirror didn't show obvious loose braces, so I went for full-on humidification: removed the strings, put it in a plastic bag w/ a lot of holes, put that plus a damp sponge in a bigger plastic bag w/ no holes, hung that in my northern NJ garage (fairly warm & humid in Spring & Summer) and let it simmer for 2 months or so. Checked it every 2 weeks as the top came slowly back to almost-correct, close enough for me to learn some more about bridge-fitting. It's still going strong!
Story #2:
Have several higher-end instruments (Martin guitars, Flatiron mandolin). I also have in-laws in Florida that get visited in mid-winter for a week or three, based on my wife's teaching & researech schedule. (We're retired now). Before adding a whole-house humidifier, I'd put a humidifier into each instrument case and seal that in a plactic garbage bag, while turning the heat down to mid-60s that our cats seemed to tolerate well. (Neighbors checked on them!) All instruments & cats did just fine.
Not sure if this will solve the sharp-vs-flat issue, but any risk of wrapping in plastic seems fairly low, to me. AND you've discovered that flat-tops / arch-tops do react differently to changes in temperature and humidity. I suspect that arch-tops react more quickly than flat-tops, thus giving mandolins the general reputation for needing constant re-tuning.
(BTW, never bothered humidifying solid- or semi-solid-body electrics. Never an issue.)
Dave Hanson
Oct-10-2020, 1:03am
Moisture cannot escape from a sealed plastic bag.
Dave H