Two tricks: First, take one of those little brass bristle brushes
for the flex-shaft, the ones where the wire is in a steel cup, all
pointing forward. Get a short one, and put it in a pin-vise, and
you’ve got a pretty good little file comb for small files. (A new
one. Used, and they bristle out too much.) This one’s also great for
cleaning carving wax out of burrs.
Second trick: Take a piece of scrap brass/copper/whatever sheet. Clip
one edge so that you’ve got a straight section 6-8mm wide. Place the
straight section down against the file, and slide it across the file,
such that it slides parallel to the main cut of the teeth. The idea
is to let it slide along the teeth, and let the teeth create grooves
in the metal. After a couple of strokes, the grooves will be deep
enough that the metal reaches down into the bottoms of the file
teeth, and rakes out any metal stuck in the grooves between the
teeth. You then just rake out a section, move the rake up the file a
bit, and keep going.
The advantage to this method is that you’re creating a custom rake
that exactly fits the file in your hand, and it absolutely will
clean out the teeth accurately.
The drawback is that it takes a minute or two to completely rake out
a file, and it doesn’t work all that well on the convex side of half-
I can completely rake an 8" silversmith’s file in 30-40 seconds, so
the time isn’t that big of a deal, but it’s not instant either. These
things are pretty much one-shot deals. Make them as you need them,
and then chuck them back into the scrap bin. The effort of saving
(and then remembering) which rake goes to what file is far greater
than the 5 seconds needed to make a new one.
Two tips that make the rake trick easier: (A) use a wider strip of
scrap to make the rake. (drawback: the wider it is, the harder it is
to get even pressure.)
(B) if you have time, curve the rake surface ever so slightly before
you groove the teeth in. This lets you rock it a bit, and get a
wider path covered without the pressure issues of a totally straight
wide rake. Makes it easier to step it up the file too.
The rake trick is pretty much the only way to get things out of #6
files, or escapement files. They’re just so fine that nothing else
really gets into the teeth.