What do you do when you have a 10-gallon brew kettle (or any other stainless ... steel or aluminium thing) with no volume markings (or Hack a Day logos)? If you’re [Itsgus], you use science to ...

Many hobbyists and hackerspaces have the $500 Chinese 40W lasercutters which most of us know are about as successful at etching metals ... without the mixture. Stainless steel is an alloy of ...