FORGE
Grindstone wheels come in different levels of
coarseness. In general, bench grinders are for
removing quite a bit of material quickly, so coarser
stones are often the most useful. As you use your
grindstones, the front edge of them becomes worn
and clogged with metal, so it’s important to periodically
dress your grindstone. This means using a dressing
tool to wear away the grit, to expose new areas. Some
people dress the front of their grindstones flat, while
others prefer a slight convex curve.
In addition to grindstones, you can get wire brush
wheels for removing paint and rust. These are
particularly useful for preparing small areas for welding,
or other adhesions. Polishing wheels can help you
achieve a fine finish on your metals.
As well as the actual spinning wheel, your bench
grinder will probably come with some accessories. A
tool rest is the most important of these. If you’re going
to be sharpening tools regularly, you may find that
the rest supplied with your grinder is insufficient and
aftermarket tool rests can provide much more control.
Grinders sometimes have additional attachments
to make them more useful – particularly in workshops
with limited space. Some come with sanders, while
others, such as the one we’ve been testing out, come
with a flexible shaft that can be used as a Dremel-like
rotary tool.
ON TEST
We’ve been testing out the Scheppach HG 34, which
is a small bench grinder for hobbyist use. It lacks the
oomph of larger grinding wheels more suitable for
heavy-duty work, but it is perfectly capable of light
workshop tasks. The grinding wheels are quite a bit
smaller than many workshop grinders (75 mm), and
there’s not much room around them for manoeuvring
large tools, but this means it takes up less bench
space for confined workshops. The rotary tool is a
complementary addition, as the sanding and grinding
bits can get into places that the main grinding wheel
can’t. It’s slower than some tools, so not well-suited
for cutting hard materials, but fine for other sanding
and polishing.
GRINDING SAFELY
The spinning action of a grinding wheel means that
bits are going to fly off, and you have to protect
yourself – especially your eyes – accordingly. Make
sure that you’ve got no loose clothing that could get
caught in the wheel, and you may need ear protection
if things get loud.
Not all materials are suitable for grinding – most
notably, aluminium. The basic problem is that it’s quite
soft, so gets stuck in the grit on the wheel clogging it
up. The wheel then stops grinding properly and can
get hot. If the wheel overheats, it can shatter. Avoid
aluminium, and if you notice the grit getting clogged,
dress the wheel (see main text) to remove this, and
never let the wheel get too hot.
Grinding wheels are rated for a particular
maximum speed, so when getting a new wheel,
check this against your grinder’s speed and never
overspeed your wheel.
As always, follow the manufacturer’s advice. The
UK’s Health and Safety Executive also has a free-to-
download booklet on the safe use of abrasive wheels,
available from hsmag.cc/jeObic.
Below
A tool rest and spark
guard help you work
safely with
your grindstone
One key thing in sharpening
all tools on a bench grinder
is not to overheat
the metal
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