Ring Resizing

Our first resizing task was to take one of our brass rings and stretch it from a size N to O½.
However all of mine were already at that size.  So I took my thin copper court ring (that I felt was too flimsy at the large size I'd made it) and cut it down so I could start at size N.  I then used the ring stretcher/reducer machine to stretch it up to size O½ (which was very easy due to the narrow width).  This method is only suitable for increases of a couple of sizes.

So now for the really tricky method.  Increasing a ring by a number of sizes with a material insert.
This is really exciting as it's not only the first thing on the course that I haven’t done before, but it’s also an industry standard method that hasn’t been taught on the HND before.

We then took another of our brass rings and reduced it by one size.
Luckily Dauvit warned us that to do this only required removing about 2 saw blade widths (so less than a mm).  I suppose that the exact amount to remove per size decrease, depends on the starting size, but it’s good to be cautious because you can’t put the material back once it’s been cut off.

I chose the flat rectangular ring to start with and cut down the solder line.  I then gently tapped it on a mandrel to expand it to the desired size.

I then cut two narrow notches, horizontally in the new ends of the ring.  These were then expanded into Vs with a triangular needle file.

New wire of similar (or larger) size to that in the ring was then bent to match the rings curvature.  I filed the end of this new wire into a point that fit in one of the rings V shaped notches.  I then cut the wire to the correct length and filed this new end into a point.
This was extremely fiddly!

The length of new wire required to increase the ring by 3 sizes was only a few mm.  This made holding it very difficult.  A number of us resorted to using parallel pliers to grip one end while the other was filed.  Even then it was hard to get the file at the right angle.
Although we were told to use a triangular file to make the Vs, I think that a square file is much better.  I find a right angle is easier to gauge by eye, and the shallower angle makes filing the new material into points much easier when there’s so little material to grip.
I wonder if you did this kind of resizing often, whether it would be worth keeping a stock of ready made inserts in various metals and various lengths...

Anyway, after a lot of careful filing on both the Vs and the points, I was satisfied with the fit and soldered the insert into place and cleaned up the newly resized ring.

I then used the same technique on a D-shaped court ring but found it harder to get a nice thin solder join on this shape.