Matched drilled assembled aileron. Disassembled, deburred and dimppled. Leading edge holes to SS counter balance were not drilled in assembly due to hardness of the SS. This was to prevent a wondering dril bit from enlarging the pre-punched hole in the alluminum skin. Hole centers were marked with a spring loaded punch and a 3/32 drill used to score the hole. After disassembley a drill press was used to finish drilling the SS counter balance., starting with a 1/16 drill then enlarging to 1/8". Caustion needs to be taken when drilling the harder SS since drill bits dul quickly. On an earily attempt using a 1/8" bit, high drill speed and lack of lubrication caused the tip of the dril bit to over heat. The dril tip melted, welding itself into the SS counter balance. This left a "high speed steel" plug at the exact spot where I needed a 1/8" hole. This was a difficult problem to over come and yeilded less than optimum results.
