Hydrate before worrying.

Like everybody else, I'd fret over the belly bump on my guitars. I'm selling a D55 now on ebay that has the flat belly of a new guitar. All I did was hydrate. I use a plastic soap bar holder with a sponge inside- lid open. I use a rubber band to make sure the sponge doesn't come in contact with wood. After putting it inside, cover the sound hole with a cottage cheese container lid. Give it 2 or 3 weeks, check the sponge every two days- and that's it. I've also brought back a D25 True American with the same trick. Hydration is a big problem in New Mexico.

But does poor hydration have anything to do with the process of a top bellying up?

My understanding is that bellying up is caused by a combination of factors: high string tension over a very long period of time, light (or loose) bracing, thin top wood, perhaps a weak bridge plate.

Neal said:

But does poor hydration have anything to do with the process of a top bellying up?

Click to expand...

Hydrating would help restore the original top radius by swelling and lengthening the top along the grain lines, and probably bracing and bridge plate too, thus helping reduce "belly".

Here'a nice little video to show the procedure. https://www.youtube.com/watch?v=tTU4KLgXH64