Back working on my bat house mold. Envision a large rectangular sink made of5/16 thick cast aluminum... I'm 'milling' a shallow slot in the middle with out a milling machine. A router with a carbide bit actually works (slowly!) as long as I take light cuts and keep it lubed up with stick wax. Running into a problem getting the slots all the way into the corners.
Have already booked some run time at my local rotational molder next month and would like to connect the slots before then. Only real machine shop I can possibly afford (semi retired relative) is not open on my normal days off and my day job is oddly wide a** open. Running out of time and ideas so I'm asking here.