AW Extra 2/28/13 – Tame Your Belt Sander

Tame Your Belt Sander

Tips to help you gain confidence and get goof-proof results.

By George Vondriska

Does the prospect of using a belt sander make your palms sweat and your
hands shake? I feel your pain. Belt sanders have a bad rap as the
quickest way to ruin a project. Use them incorrectly and your project
starts to look like the rolling hills of Ireland. But used correctly,
they're a great tool for flattening panels, flushing up trim and face
frames and getting to the finish line fast. Start by learning the
belt-sander rules of the road:
• Keep it moving. The slightest pause can form a gouge.
• Let the weight of the sander to the work. Don't lean on the machine.
• Use nothing but 120-grit paper until you're comfortable with the machine.
• Don't overextend yourself. Running a belt sander at your reach's extreme end is a sure way to gouge material.

1. Start with a soft landing. Before you pull the
trigger, lift the sander slightly off the workpiece. Squeeze the
trigger as you ease the sander down and forward, feathering it into the
material. Think of it as an airplane making a smooth landing.

2. Go over the edge, but only a little. As you sand to an edge, allow the
platen to project over the corner, but never by more than half its
length or width. This keeps the sander balanced and flat.

 

3. End with a smooth take-off. OK, you've
successfully landed your sander and finished sanding. Now it's time to
take off. On your last stroke, lift the sander as it moves forward.
Then release the trigger.

Setting Up

A big part of the battle is won just by taking the time to set up properly.

Get the height right. The surface you're sanding should
be slightly lower than your waist. This puts your arms at a comfortable
working height. For some projects, like cabinets, it may mean working
on a surface other than your workbench. Make sure the piece you're
sanding is secure. It's also good practice to keep the cord out of the
way by draping it over your shoulder. It looks weird, but it prevents
frayed cords— and nerves—from belt-sanded wires.

Provide solid stops. You can't sand a piece that you're
chasing around the shop. Belt sanders are powerful and have a tendency
to launch projects off their perches. Be sure your material is trapped
against stops that are firmly clamped to the bench. Clamping the
material itself to the bench is a hassle because the clamps get in the
way. The stops should be thinner than the material you're working on
and wide enough so the sander won't bump into the clamps.

Trueing Up

A belt sander can flatten a glued-up panel in no time.

1. Sand diagonally first. Flatten a solid wood
panel by first sanding at 45 degrees to the grain using an 80-grit
belt. This helps level the high spots that often occur at the joints.
Use a straightedge to check the panel, working the angles in a
crisscross fashion until it's flat. Note: Never sand plywood at an
angle.

2. Then go straight. When the panel is flat, sand
parallel to the grain, using the same 80-grit belt, until the cross
scratches from your diagonal sanding are gone. Each stroke of the
sander should overlap the previous stroke by half a belt width. Pencil
marks help you keep track of where the sander has been and where it
needs to go. When the cross-grain marks from the previous step are
gone, change to a 120-grit belt and work the entire panel again.

Tooling Up

It's a poor craftsperson who blames the tool, but it's hard to get
good results from a prehistoric belt sander. Here's what to look for in
a new belt sander.

Eliminate gouging with a sanding frame. A sanding frame ($50 to $80) is
like training wheels for a belt sander. Unlike training wheels, you'll
never want to remove the sanding frame. A slick surface on the bottom
of the frame rides on your material, and the sander is suspended within
the frame. This is a no-experience-required way to keep the sander
under control and dead flat. Some frames even have micro-adjust knobs
that allow you to control how much material the sander is taking off.
Frames really shine when you're working on large surfaces. Not every
belt sander is made to work with a frame, so if you're buying new, it's
a feature to look for.

 

 

Clean belts = better results. An abrasive cleaning stick, epoxied to a
board and clamped nearby, will keep your belt clean and working hard.
Abrasive cleaning sticks act like an eraser for sandpaper. At less than
$10 per stick, it's a lot less expensive to frequently use the cleaning
stick than to frequently change paper.

 

Variable speed gives you better control. A belt sander set on low speed
and equipped with a fine-grit belt is easy to control. It's especially
useful on veneered materials. If you want to hog off barrels of sawdust
quickly, switch to a higher speed.

 

Get the right belt. Look for no-lap belts for your sander. The seam is
a butt joint with high-strength tape holding the back of the joint
together. Belts with lap joints tend to have high spots that go thump,
thump, thump, as you sand, which makes controlling the sander more
difficult.