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Working With Sheet Metal
So, you would like to work with sheet metal. Outlined in this
section are a number of skills that will help you add sheet metal
to your wire jewelry designs:
Making a template
Preparing Saw Blade & Bench Pin
Sawing
Drilling
Filing
Sanding
Buffing
Finishing
The skills listed here are not difficult, although they will
require practice. If you get stuck or discouraged, ask for help
from an experienced metalsmith who can give you face to face
guidance. Have fun and I hope you enjoy incorporating sheet metal
into your wire jewelry.
Safety Concerns:
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1) |
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Wear a particulate respirator mask whenever you stir up dust
from metal, or polishing compounds. |
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2) |
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Avoid eating, smoking and drinking in an area where there is
metal or compound dust. |
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3) |
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When working with power equipment, always wear safety glasses
and avoid loose clothing. |
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4) |
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Remove jewelry when working with a buffing machine. |
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5) |
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Follow all safety recommendations that come with power tools
such as the flex shaft or buffing machine. |
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6) |
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Ask for help if you need it. |
Create A Template
First ask yourself “What do I want to create?” You
may find it helpful to sketch some ideas prior to making your
template. Consider making your sheet metal piece out of cardstock
and assembling it as if it is sheet metal. For example, if I
am making a sheet metal pendant, I can join all of the necklace
components together (including the sample in card stock) and
try the piece on. I will be better informed about how successful
my design is. Once your are committed to a concept, using card
stock, draw and cut out a template to be used as a pattern.
As seen in the image, I am making the front piece for a Santa
Fe Bangle. Transfer the shape of your template to sheet metal
using a permanent pen.
How do you know what gauge sheet metal to use? It depends
on your project. The function, appearance, and scale of your
design will help determine the gauge you choose. With experience
you will discover what gauges work best, but, in the meantime,
here are a few suggestions:
Charms and dangles – 22 to 26 gauge
Cuff – 18 to 22 gauge
Santa Fe Bangle front piece – 22 gauge
Corrugated sheet metal – 30 to 34 gauge
Pendants – 20 to 22 gauge
Earrings – 22-26 gauge
Preparation: Secure The Saw Blade
Loosen the top screw of your jeweler’s saw frame thereby
opening the clamp where the blade can be secured. Carefully (blades
are VERY sharp) place the top of your saw blade into the clamp
and tighten the screw. Please see the chart below for determining
the appropriate saw blade for the sheet metal you selected.
How do know you which way to place the blade in the clamp?
Think of a fir tree. The branches face away from the trunk, and
they slant down. The teeth of your saw blade should be facing
away from the saw frame and slanting down. You can gently feel
the blade to determine its correct position.
Now, the challenge is to tightly secure the bottom end of
the blade in the lower clamp. Adjust the outside third screw
of your saw frame so that the saw blade just touches the upper
portion of the bottom, left clamp.
Grab a hot pad from the kitchen and place it at the bottom
of your breast bone. Place the top of your saw frame in the “V”
of your bench pin. If you don’t have a “V” in
your bench pin you will need to cut one out with your saw frame
after you secure the blade (see below). Press the bottom of the
saw frame handle into the folded hot pad and push on the handle.
(If this procedure is uncomfortable, add more padding underneath
the handle of your saw frame). This pushing action shortens the
space between the upper and lower nuts.
Loosen the bottom screw and carefully introduce the bottom
of the blade into the clamp. Tighten the screw and release the
pressure on the handle. Gingerly test the blade by strumming
your index fingernail from the back to the front of the blade
(there are no teeth on the back of the blade so you are not in
danger of cutting yourself). The blade is tight when you hear
a high pitch “ping”. The blade should be taut and not
collapse as you saw your sheet metal. If you are breaking blades
one possible problem is the blade is not tight enough.
16 gauge sheet metal - #2 saw blade
18 gauge sheet metal - #1
20 gauge sheet metal - #1/0
24 gauge sheet metal - #4/0
26 gauge sheet metal - #6/0
28 gauge sheet metal - #8/0
30-34 gauge sheet metal - cut with shears
Preparation: Saw A “V” In The
Bench Pin
Place your bench pin on the worktable so that the flat side
is facing up. With a pen mark a “V” on the right hand
side if you are right handed, and on the left if your are left
handed. My “V” is about ¾ inch at the base and
1 inch high. With yours saw blade cut one side of the “V”.
You do not need to put a lot of pressure on the blade –
let it do the cutting. When you reach the top, loosen the upper
nut and pull your saw frame down to release the blade from the
wood. Secure the blade in the lower nut and cut the other side
of the “V”. Please note: Some bench pins are flat on
both sides and generally come with a clamp to secure it to your
worktable. Others are constructed to fit into an anvil which
is then clamped to your table. If you have the latter piece of
equipment, introduce your bench pin into the anvil with the flat
side facing up. The back of the bench pin should be sitting on
top of your table.
Saw The Sheet Metal
Sawing is a skill that develops with practice. Add lubricant
(beeswax, Cut Lube or Bur Life) to the blade by running the stick
up and down the blade. The image shows you how to place your
index and ring fingers to stabilize the sheet metal as you saw.
With smooth movements up and down with the saw frame, saw
between your fingers and in the open “V” section of
the bench pin. Sometimes you will have to re-position your fingers
to stay clear of the saw blade. Saw the outside perimeter of
the sheet metal.
Tips On Sawing
1) Use the correct size saw blade for the sheet metal gauge.
2) Make sure your blade is nice and tight.
3) Lubricate the blade.
4) Practice sawing on copper or brass sheet before diving into
silver.
5) The blade should be perpendicular to the floor as you saw.
6) Saw with a light hand – no pressure on the blade.
7) Use long smooth movements; use most of the length of the blade
to saw.
8) Turn corners by “sawing in place” as you turn the
metal and the frame.
How To Saw A Hole In The Center
Some of your designs may require you to saw out the middle
section. To do this, you will need a flexible shaft motor, Dremel,
or a hand drill. Insert a small (#50 to #57) high speed steel
twist drill into the drill collet. Insert about 1/3 of the drill
bit into the collet – it is less likely to bend or break
if you do this. In the image I am using a flex shaft inserted
into a drill press especially designed for the Foredom Flex Shaft.
Alternatively, you can drill by holding the flex shaft handpiece
in an upright position. Before drilling, use a center punch and
a mallet to create a divot in the central section of the sheet
metal. Note: You may also use a hole punch if your sheet metal
does not exceed the gauge tolerance for the punch.
Don safety glasses, hold the sheet metal with a ring clamp,
place it on a piece of wood, and drill a hole into the divot.
I suggest using a ring clamp to hold the metal instead of having
your fingers in direct contact with the metal. Although it does
not happen often, a drill bit can bend or break in which case
you don’t want your hands in the vicinity of the drill bit.
Another unexpected thing can happen where the drill bit grabs
the sheet metal which then spins up the bit. Again, you don’t
want your hands in contact with the sharp sheet metal.
Remove the blade from the bottom clamp of your saw frame.
String the blade through the hole; reinsert the blade into the
clamp.
Saw the inside section of your piece. Remove the sheet metal
from the saw frame by loosening the bottom nut. |
Working
With Sheet Metal Tutorial