Welcome to the fifth entry in this series of articles. In this article, I will be demonstrating the process I use to fabricate tubing out of precious and semi-precious metals (specifically fine silver will be used in this “tutorial”). You will need to know how to solder to fabricate tubing, so if you don’t know how to solder yet check out the “Fourth Entry: How to Solder (An Introduction to Silver Brazing)”. Fabricating your own tubing is in some ways very similar to drawing your own wire, so I also recommend reading the “Second Entry: How to Make Wire (Manually Drawing Wire)”; if you are not already familiar with the process of fabricating wire.
Necessary Materials and Tools:
-Small Paint Brushes/ Tweezers/ Soldering Picks -Soldering/ Annealing Area -Measuring tool (caliper or gauge plate)
As is often the case, there are many roads, and they all lead to Rome... Making tubing is no exception. There are many methods and this is just how I have come to do it after making many tubes over the years. The most important aspect in this process is making sure you have a quality sheet of material with nice parallel edges to start with.
TIP: If you have a nice clean factory cut sheet to work with, you can simply trace a parallel line down the sheet with your compass. Cut straight down this line and you should have a nice parallel strip of material. No straight edge to start with?... Make a straight line with a ruler and scribe, cut the line, file the edge straight, then trace a parallel line with a compass off of that line.
A nice trick I have figured out, is to start with a thick piece of wire and roll the material out into the exact dimensions you desire. To learn how to roll your own sheet metal take a look at this entry “Third Entry: How to Roll Sheet Metal (Creating Gold Foil/Leaf)”.
Wire before rolling through the mill.
The tubing I am looking to fabricate is to be used for hinges and stone settings. For this reason, I want to create a sheet of metal at least .3mm thick. This will provide the tube with some “wall” material to work with (I want a tube with fairly thick walls). Since this tube is supposed to satisfy a variety of needs, I am not paying too close attention to the length and width of my sheet. My goal is to create a sheet that will create a tube/cylinder around one of the smallest punches I have.
NOTE: Although the punch is small, it will create a rather large tube just able to pass through the largest opening/s of my drawplates.
To produce the necessary sheet of metal, I roll the thick wire through the rolling mill “width-wise” (I want to make it wider, not longer). Once the desired width is obtained I then roll the sheet length-wise until the desired thickness is obtained. The extra length will only give you more tube to start with, the more important characteristic for the tube will more than likely be the wall thickness (determined by the thickness of the sheet).
Wire after rolling through mill, now ready to be turned into a tube/cylinder.
IMPORTANT: Make sure to anneal your material when necessary!
In this process it is always necessary to create a tube/cylinder larger than what is actually desired. This is done so that the tube may later be drawn through the wire drawing bench to give the piece a true, well defined shape and to achieve the desired diameter in the end. A nice benefit to this is that if a large tube is created, it can be fairly easily resized to any smaller diameter; thus allowing you to create a wide range of tubing.
IMPORTANT: Make sure you create a tube/cylinder that can pass through a draw plate! Don’t make it to big!
Hammers, small punch, fine silver sheet and design block… Ready to make a tube!
If you are un-sure of your sheet you can always file the edges a bit to make sure they are parallel and smooth.
Once satisfied with your sheet you can begin to form it into a cylinder around a punch or other mandrel.
IMPORTANT: Make sure your material is annealed before you begin to form it!
To do this place your sheet into the groove of the design block it best fits into.
Once in position, begin to press down on the sheet to curve it into the groove and around the mandrel. Try to do this as evenly as possible so that the two ends of the sheet make a straight line when they meet.
NOTE: With harder materials it may be necessary to do this with a mallet or hammer!
As the sheet conforms to the shape of one groove it is necessary to move on to smaller grooves.
Once the sheet begins to curve over the top of the mandrel you may be able to push the sheet over and around the mandrel with your fingers.
As the sheet is formed, the material loses its elastic properties and must be annealed so that further forming /manipulation may occur without damaging the material.
After annealing the soft silver can be easily bent over the mandrel with one’s fingers.
IMPORTANT: Take your time when closing your tube! It is far too easy to accidentally push your sheet too far.
As the sheet gets closer to having its ends meet, it is helpful and often necessary to use a mallet and/or hammer to work the sheet completely around the mandrel.
Once the ends are about to meet and the sheet is becoming tight around the mandrel, the sheet (now a tube/ cylinder) can be removed from the mandrel and the fine tuning can be done.
To do the “fine tuning” I place the sheet (without the mandrel) on to a flat steel surface and gently hammer the edges down until they meet to form a tight seam.
Once you are satisfied with your seam the newly formed tube should be annealed before soldering.
During annealing the material might shift/warp a bit and you may need to redefine your seam if the edges drift apart.
IMPORTANT: If you are going to quench your piece after soldering or annealing be sure to use caution as boiling water and steam will shoot up the tube and may burn you!!!
It is important to anneal the piece so that if your material does warp, it does not do so while you are attempting to solder. After annealing it is easy to define your seam by gently hammering directly on top of the joining edges.
Now that I know my seam is not going to move, I can begin to prepare the piece for soldering.
NOTE: Be sure to solder your tubes with a hard solder as you will most likely want to solder your tube/s to other pieces after they are made.
As always begin to heat the piece slowly, working the torch calmly up and down the piece. As the flux secures the solder chips to the piece, the heat can be more intense and focused. I have always found it easiest to heat from the bottom and to pull the heat from one end to the other as the solder begins to flow.
After soldering, the tube should be pickled and cleaned.
Once the tube is nice and clean, the seam can be inspected for gaps or other problems.
If the seam appears to be whole and intact, the excess solder should be filed off the exterior of the tube.
Once the excess solder has been filed off, the tube must be tapered to fit into a draw plate. You could hammer one end into a taper or smash and fold it until it forms a taper.
But the simplest and most effective method to do this is to taper one end using a wire rolling mill (if you have one available).
After tapering the tube we can now move onto the drawplates. You can use any shape drawplate you wish as long as the tube fits. Since I plan to make hinges I will be using a round drawplate.
Just like you would do as if you were drawing wire, find the right size opening in your drawplate to begin drawing out your material.
Once you find the appropriate opening in your drawplate, begin to draw the tube out into a true round or whatever other shape you may be able to produce.
Continue drawing out your tube until you reach the desired diameter for the application you require. Make sure to anneal the tubing when necessary. I will typically only make two or three passes through the drawplate between annealing’s. I do this to avoid over stressing the soldered seam, as the solder is usually not as malleable as the rest of the tube; and this makes the seam prone to cracking.
NOTE: The solder seam on your tube makes an excellent temperature indicator when annealing. Make sure not to over anneal your tubing as you may burn out your solder seam.
If you need a thick tube and a tiny tube or tubes that “telescope” (fit inside of each other) or a series of different sized tubes. Cut the tube in half and continue drawing out the tapered half until it fits inside the other half… It’s that simple.
Keep drawing out your tubing and annealing when necessary. Cut your tube and continue drawing the tapered half to produce a wide range of tube diameters.
NOTE: Depending on the amount of tubing/s you require you may have to form another tube. Alternatively you could always create a really long tube from the very beginning; if you know you are going to need a bunch of tube/s.
This tube is still too large for me to cut and continue drawing out, but it now has a nice clean round shape. I am going to leave it at that for now as I am still unsure as to exactly what I will be using this tube for, but hopefully you get the idea by now.