Homebrew PCBs

> fairly well. I have a number of solid carbide PCB drills that have broken,
leaving a
> 1/8" diameter carbide drill rod about 1" long. I chucked these in my lathe
and
> used an angle grinder with abrasive blade to grind a point on the end of
the rod.
> 
> I have been told that carbide dust is quite dangerous.  Are these concerns
> overblown?  Do you take precautions?


The boards are made from fibreglass, the dust from cutting it isn't overly
good for your health.  The particles are sharp and stick in your lungs, it
gives you something like from asbestos, silicosis (breathing in dust from
sand-blasting) etc.  Same goes for drilling holes. 

It'll take a while; the problem is that unlike most things that take a while
to build up (eg lead poisoning) and get flushed from your body in the
meantime, dust like this will happily sit in your lungs forever.  If you're
susceptible you'll find out in 20 years.

That's cutting the board itself, just cutting the copper will put out less
dust.

Some people prefer to 'score & snap', or cut it with shears.  That's not
always possible if you're cutting slots in the boards (HV isolation etc) or
funny shapes.

Tony