Kenneth Michael Guitars est.1978
"Reverse Rounded Kerfing – More than “Eye Candy”  
It is my belief that a rigid guitar rim, when teamed with a thin, lightly braced top has a
good chance of producing a nice sounding guitar. I would sight the banjo and just about
any drum for the acoustic evidence. I first started using reverse rounded kerfing
because I liked the clean look when viewing the interior through the sound hole. To my
surprise I discovered that once PROPERLY INSTALLED the rim is self-molding, in other
words when taken out of the form the rim keeps its final shape without the top or back
assembled. To me that’s rigid ---- one of the biggest advantages is the neck block is
less likely to twist out of position during final assembly.
This photo illustrates the strength of the laminate effect created with the reverse
kerfing. The strip of Sapele about an inch wide and was thinned to .080” the left side
has the kerfing glued in the conventional manner. The strip is 22” long and clamped in
the center. On the LH side I placed approximately ½ lb of screws, note the deflection of
about 2 ½ “. On the RH side I placed 2 lbs of screws and there is zero deflection ---
very rigid!!
To properly install reverse kerfing an extra step is required in the process. It’s my guess
that’s why more builders are not currently using it. To avoid breakage, in tight curves,
the kerfing needs to be pre-bent. The way I do it is simple, but requires an extra day or
so for the kerfing to dry out. I simply spray the kerfing – on the solid side. Wrap it in
aluminum foil for a few minutes so it gets pliable. Pre-bending is accomplished by using
many clothespins to clamp the kerfing on the OUTSIDE OF THE RIM. This provides
backing to help the solid layer take the shape of the rim. Once its dry remove and
install as normal.   
In addition to a superior strength rim --- IT REALLY LOOKS GOOD!
Our KMG Mircoslot © reverse rounded kerfing is made on a propietory machine
using a .014” wide blade, in addition to the clean appearance, the thin slots allow
each 3/16” section to bond to one another. I recommend applying thin applications
of glue to the sides and the kerfing