to cut the solder as small as possible, is with my side cutter a
irritating exercise, they have different sizes and have the
tendency to fly all over the place.
With sheet solder, or your flattened wire solder, instead of side
cutters or those odd solder clippers (which I don't like either), use
a pair of good small shears or snips. Sometimes actually called
solder snips, they have jaws that look like small scissor blades,
rather than nippers.
Use the shears to cut paralell cuts into the sheet a little ways,
not all the way across, much like the teeth on a comb. Try to make
the cuts the same width if you want the same size pieces. the little
lengths will curl as you cut, so when you've cut enough lines, use a
flat plier to flatten the sheet again. You don't need to get all the
curl out, just evenly flat enough so you can now cut across the first
line of cuts. Your index finger of the hand (in my case, my left
hand, as my right is holding the shears),extends under the shear jaw
(they're small), and traps the little pieces on the other side of the
blade, so most of them stay where you're in control. A few might get
away, but most will still be on your fingertip.
While it's hard to get everything the exact same size, you can
usually get pretty close, and you can cut the bits quite small.
The other trick would be to draw your wire solder down to a smaller
wire. As small as you like. Then even longer pieces snipped off, will
be a small amount of solder. Another trick, is to wind the solder
wire up on a tiny mandrell (like a drill bit shank, if you like. Then
cut that coil to give a whole bunch of tiny rings. They will all be
the exact same size, and the exact same amount of solder. This is a
method often taught for how to make granules all the same size for
granulation, and it can work just as well when you need exact
amounts of wire solder. Drawing the wire down to a smaller size, and
using a smaller drill bit shank to wind the coil on (there may be
other things you can use as a mandrel, but I've not found anything
better) can give you quite small amounts of solder or metal. I like
to use the very thin seperating disks (.006 inch thick) to cut the
coils. Easier and quicker than a saw.
And finally, be aware that if you always use your solder the same
sizes, many metals suppliers, at least the bigger ones, can sell you
solder already in the form of clippings. Whether they are available
in the size you need, you'd have to ask. But maybe...