Pinewood Derby Stories and Photos from Maximum Velocity
Here is a tip that I have used many times to repair broken appendages, saw mis-cuts, and any other case where too much material has been removed from the car. The answer: Bondo auto body filler (which works better than wood putty). It can be mixed to harden in 15 minutes or less to a point where it can be shaped with a knife or rasp or file or sanded. It is usually softer than the wood and can be sanded away without taking much from around it.
My daughter designed a hammerhead shark for her Awana grand prix car two years ago and I broke off about 1/2 inch of the tail while doing something (I don't remember what, but I had to fix it). I tried to glue the piece back on but it kept falling off. I 'globbed' some Bondo on and shaped it with a knife and sandpaper and it lasted through all of the races and is still in place (she even took 1st Place for design that year). You can also use Bondo spot putty to fill in end grain or deep sandpaper scratches or nicks or dents or any small problems. It dries in about 5 minutes, and then can be sanded. I always paint the "finished" cars with primer to be able to see any of these small problems and then fill them with spot putty.