Finishing the inside

[jjadamson]

I've just finished building martin guitar and I'm very happy with the finish on the outside but on the inside it looks a little untidy with water marks showing from wet rubbing the nitro. It just looks a bit "dry". Is it wise to rub a oil or shellac onto the back and braces.

[B. Howard]

Most people do not finish the inside although I have seen it on occasion. I do however sand and polish the insides before I close the box. I scrape away the scorching and water stains, sand at 220 and then burnish the entire surface with gray scotchbrite.