Kerfing is a wood lining that is glued to the inside of the top and bottom of the rim (sides) of guitars, ukuleles, mandolins, etc… to create an interior surface, onto which the top and bottom of the instrument is glued. It comes in several different styles, and I have come to really like what is called “reverse” kerfing, where the narrow strip of wood that holds the strip together is on the outside, as opposed to on the inside, which is more ‘traditional’. I have found that reverse kerfing adds a tremendous amount of stiffness to the sides, that normal kerfing does not. Once the reverse kerfing is installed, you really can not flex the sides any more. I make my own kerfing because I really like to make as much of the instrument as possible, I can make kerfing using light or dark woods to better match the sides, and can make it in a ‘ukulele’ size, as opposed to guitar kerfing which is mostly what is commercially available.
