Happy Manufacturing Monday from Adafruit!
A well maintained soldering machine is a happy soldering machine. Here you can see a solder nozzle being tinned in preparation for a big run of new Metro M4 boards.
Tinning is done by dousing the nozzle in liquid flux before fully submerging it in molten solder, thus removing any impurities from its surface and coating it in a protective (and very pretty) layer of tin.
Metro M4 in stock now!