The resonance of a drum is partly determined by the integrity of the wooden drum shell. Cracks, holes, dents and nicks in the shell can decrease the resonance of the drum as well as compromise its structural strength and visual appeal. Damage to the drum can occur when the drum is transported to a location or because of sudden changes in temperature or humidity. Hot and dry weather, for example, can cause a drum shell to crack. It is relatively simple to repair drum-shell damage using wood filler and epoxy.
Remove all hardware from the drum shell so that you can thoroughly assess the drum head. Look for cracks, splits, dents and holes in the shell both inside and outside the shell. You can ignore any imperfections which will be entirely covered by hardware once it is replaced, presuming these do not affect the structural integrity of the drum.
Glue any cracks in the shell using a two-part epoxy such as the marine glue manufactured by WESTSystems. This is a relatively runny epoxy, so let it run into the first crack in the drum shell. Place a piece of plastic, such as a shopping bag, over the repaired crack and then place and tighten a clamp over the shopping bag while the epoxy dries and bonds the crack. Repeat for every other crack you find in the drum shell.
Fill any small holes, dents and nicks in the drumshell with a wood filler such as DAP's Plastic Wood. Apply enough wood filler to completely fill the hole in the wood, with a little excess filler protruding beyond the surface of the drum. Wait for the wood filler and epoxy to dry completely.
Sand down the areas repaired with wood filler until each is completely smooth and flush with the surface of the drum. Depending on the finish of your drum, you may want to lacquer, stain or paint the entire drum so that the repaired areas blend in visually. If your drum is covered in a wrap finish, you could re-wrap the whole shell or just the areas that were repaired. In the case of vintage drums--and as of 2010, any drum built in the 1980s or earlier is considered "vintage"--it is preferable to retain as much of the original finish and wrap as possible.
If possible, make repairs using wood filler from the inside of the drum shell so as to preserve the original wrap and finish.
Wear a dust mask when sanding to protect your lungs.
If your drum is very old, rare, or valuable, an amateur repair job could damage the value of the drum. Take rare drums to a professional restorer.