From Edwin Erickson, accordion tuner, who has had to deal with a few messes made this way: : People wonder about the integrity of accordion tuners and technicians. Please don't put too much faith in what you see on KZbin! This is a perfect example of what NOT to do in accordion tuning. 1) You can never expect to make even a mediocre tuning job with the reedblock outside the accordion body. Airflow within the accordion itself is unique and critical to the final outcome. 2) NEVER let anybody with a power tool within 10 feet of an untuned accordion! The person in this video is in the process of ruining some very expensive accordion reeds, for two reasons: a) the probability of removing too much material from the reed tongues is imminent, b) the temperature reached with the use of such a tool can, and probably will, damage the temper of the steel and render the reed useless.