That's exactly how I hurt my hands, pushing down on my big sprue
cutter against my workbench. Bronze sprues are way too hard to cut
by hand, at least with my hands...
Kathy, while the cutters sold to jewelers as sprue cutters are
indeed nice tools, they don’t compare to an actual bolt cutter.
Industrial bolt cutters are (or can be, since they’re made in
different sizes) substantially larger, and are always a compound
action, so that a large movement of the handles translates to a
small movement of the jaws. That results in enormous mechanical
advantage, meaning that unlike the commercially sold jewelers sprue
cutters, a properly sized bolt cutter does not need much effort to
cut. Keep in mind that they’re intended to cut steel bolts, so a
cutter that can slice through a 1/4 inch or larger steel bolt will
handle a bronze sprue like childs play. Beyond the already mentioned
advice to just rest one handle on your stump or bench, you can mount
it permenantly, strapped to a sturdy bench. That makes it truely a
one hand tool.
The main downside to bolt cutters as opposed to specialized sprue
cutters is that bolt cutters are designed with jaws sturdy enough do
to their job, which means kind of thick and blunt. So you cannot cut
quite as close to your casting as you might with an actual sprue
cutter. But you’re casting bronze, not gold, so the slight extra
waste shouldn’t be an issue.
Also, I’d suggest that rather than Harbor Freight, you get a
Craftsman brand from Sears. Unlike their power tools, many of their
hand tools still carry the traditional Craftsman’s lifetime warranty,
so if that applies as well to their bolt cutters (I don’t know for
sure, but believe it would) If you ever break the jaws, they’d simply
replace them. And, the quality of their tools, even the ones made
these days in China, are better than what you’re likely to find at
If you’re unsure, take one of your bronze sprues and go into Sears
and try them out, perhaps with a sales person’s assistance, and
you’ll see what I mean about how little force these things require
for even heavy duty cutting, if you get one sized correctly for your
sprues. The potential cost savings makes that little shopping trip
worthwhile over buying a powered cutter. Note too, that power cutters
are also not immune to chipping and breaking cutter jaws, and some
of them get pricey to replace. If you do large volumes of such
casting, then perhaps the faster power cutters would justify that
cost, but at least check out the bolt cutters first. With the right
one, you will not be hurting your hand at all.