Never had a problem with the keyboard with corrosion of any kind, inside was clean as a whistle. A few nights, though, I actually place sheets of Saran wrap over the keyboard to keep the dew from settling on the keyboard. You would be amazed at how effective that was, and I was able to still play the keyboard, though sometimes I hit a bad note because the Saran wrap pulled down an adjacent key. I had a couple nights when I was playing beneath a Tiki Hut and the humidity was so bad that water dripped off the thatch roof as if it were raining.

All the best,

Gary