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Making tubing is an important skill that is necessary in
goldsmithing. Whether the tubing is used to make a hollow
article, hinges, or sections for setting stones, the ability
to make different diameters and wall thicknesses of tubing
will stand any metal worker in good stead. It is possible to
work only with commercially made tubing in a jewellery
workshop, however, making specific tubing, with
specific wall thicknesses and diameters gives the workshop
far greater flexibility. The one disadvantage with workshop-
made tubing is that is has a solder seam, whereas factory
made tubing does not. However, if the seam is made
correctly, this is a very small disadvantage. In this
tutorial, I will use silver, but my method applies to all
precious metals commonly used in the trade.
I start with a piece of metal rolled to the correct
thickness I want. In this case I started out with .64mm. The
metal walls will thicken up slightly when the tubing is
finished, but not so that it is a cause for concern. For
instance, after I had drawn it down three holes the wall
thickness
was .67 thick. The sides of the flat piece of metal are completely
parallel, and it is cut to a point to make the first draws
through the drawplate easier.
Once the one side of the metal
is flat, I use a divider to scribe the correct width. This
will then be cut parallel to the flat side. I determine the
width by multiplying the wanted diameter tubing by 3.14, and
then adding 1.5 times the metal thickness. Of course, I
always make the diameter that I want a bit larger than my
final size, because I am going to draw the tubing to the
required diameter. Also, I always make a long piece of
tubing, much longer than I need. That way I draw stock down
to what I need, as I need it. The metal shown in the
pictures is just for demonstration of this tutorial.
Then I put it in a swage block and bend it roughly round
using an appropriate mandrel.
I continue to do this, using a thinner and thinner mandrel
until the two sides meet.
Then I pre-draw it through my drawplate to get the sides
nicely closed. Then I anneal it and draw it through
the same hole again. I do this, because when the metal is
drawn and bent it slightly work hardens. Then, when I anneal it, the
seam will pull apart slightly. One pull through the last
hole tightens it nicely again in an annealed state.
Nicely closed and ready for binding wire and soldering.
A good practice is to use your scriber and score it down the
seam gently before you solder. This scratch brightens the
metal at the seam, allowing for a cleaner solder joint.
Now I bind binding wire around the tube to further prevent
it from opening during soldering. Always use two twisted strands
of wire. It allows for more even tightening and less
expansion when heat is applied
I use a flame like this to solder. Just a hint of yellow
makes for a slightly bushy reducing flame. I use a No6 nozzle
Soldered. Now I will use a fine file to file any excess
solder before I draw it down further.
I then solder a piece of wire in the piece of tubing if I want to draw it down to a
thinner diameter. Should the wire need to be thinner, I roll or file it thinner. The total time that it takes me to get
to this stage from melting the original metal in the plate ingot, is half an hour. Tubing can be used in this
Jewelry Tutorial - Making a Fold-Over Catch and
Jewelry Tutorial on Making a Bayonet Catch also advanced used in
How
to Make Composite Metals.
If you have any questions or wish to be notified of any new tutorials that are posted,
email me at hansmeevis.tutorials@gmail.com
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