One of my students said I should have called my last post "File Files" so I tried to think of a lame pun for tubes, but couldn't think of anything. Anyway! Tube making! I like to make my own tube because I like the process but also because it means I can make exactly the size I want. Of course, you could draw down seamless tube bought from a supplier, but I do just like the feeling of achievement that comes from producing some tube from flat sheet. Also, I get to use one of my favourite tools: the drawbench. Luckily, there is a drawbench at Studio E174 (new classes starting in April!). Here it is: (click on the photo for larger view)
If you're drawing down wire, you are either making it the same shape but a smaller width (for example, 1mm round wire down to 0.5 wire) or you're drawing it into a different profile shape (for example, from round wire to square wire). There are a variety of reasons for doing this - maybe you want to harden your wire, maybe to need smaller wire, maybe you need a bespoke size wire that isn't available from bullion suppliers. The last is especially true for gold, since it's sold in a more limited range of sizes than silver. When it comes to tube, it means you can get exactly the size you want and you can experiment with different profiles as well. Anyway, the drawbench holds the drawplate at one end and holds the tongs along the top and you crank the handle to pull the tongs along and pull your wire/tube through the drawplate.
To make tube, you cut a piece of sheet with a sort of ant-eater nose at one end. Then you start with the largest hole in a drawplate of large size holes and slowly work your way down in size. Lots of annealing is required and the point of your sheet will break off and need to be filed back into a decent point so it can fit through the drawplate. Do not make the sheet too wide to start with, as with this copper example (middle piece), or the sheet will cross over instead of meeting in a seam.
Here's the set up with the drawplate at one end, the silver tubing sticking through the drawplate and the tongs gripping the tube.
If you're working with a larger piece or it's all being rather difficult, you can also use a lubricant like wax to help the wire/tube move more smoothly. Drawplates can be bought for a range of budgets. If you're going to be using them lots, then a more expensive one is worth it - the drawing down is smoother, the resulting shape is more consistent and neater. Some cheaper drawplates aren't that well made, so they leave grooves or lines on the finished piece. It depends on what you're doing if that's important or not.
In the first photo, we have the tube as it's coming together, the forming of the seam. In the second photo are the finished bits of tube (which I use for brooch findings). I straightened it just by hand. You can also roll it between two bits of steel to straighten. You can solder your tube seam shut at this point, but as I only use very small pieces at a time, I solder seam down on the piece so it's soldered shut at that point instead.This is obviously not an exhaustive post about tube making - you can read more about tubing by he-of-the-brilliant-name, Charles Lewton-Brain over on Ganoksin here: http://www.ganoksin.com/borisat/nenam/tube-hints.htm