I have been working on refining the process of shaping the nickel bands that I use in repairing cracked shanks. The pressure fitting of round or oval bands is relatively easy. The round bands merely need to be heated and then pressed into place. The oval bands need to be “squashed” to size. This is a bit trickier in that you need to figure out the diameter of the “unsquashed” circle of the shank and match that with the band size that will be used. Doing this has been a bit of an experimental process for me. I am getting to where I can estimate the size and when it is shaped accordingly it fits well. But that took time. I have no special tools to help with the measurements other than a tape measure that enables me to get close to the size I want to begin with.
But when it comes to shaping a diamond shanked band or a square shanked band that is a different matter altogether. I begin with a band that has the same diameter as the shank of the pipe I am going to work on. I squeeze it to an oval and try to pinch both ends to get a fold. I then squeeze it into an oval the other direction and pinch the ends. This gives me a band that is in essence a square with a bulge on each side.
Once I have the basic shape squared as it appears above, I use a flat blade screwdriver to square up the corners. I place the blade of the screwdriver flat against the inside edge from one side to the other and then push the outside edge with my fingertips working my way around the square on both sides. With this process I have roughly squared up the band and it is ready to be placed on the shank of the pipe.
I slide it on the shank of the pipe as far as it will go without binding and then use a small furniture hammer (picture above) to square the edges of the band. I then reverse the band and do the same thing a second time. I am very careful with the hammer as I do not want to crack the shank. I merely want to get the band as square as possible before I heat it and pressure fit it on the shank. The next two photos show the squared band after it had been put on the shank and tapped into shape with the hammer. I finished by reinserting the screwdriver and squaring off the corners.
That is the journey in photos and words from a round to a diamond/square band. As you work with bands and improve upon my method keep us posted. I am always open to learning better and more efficient ways of working. One thought I have had is to get square blocks of various sizes of either hardwood or metal and use these inserted in the band to allow me to flatten the band more thoroughly and sharpen the corners. But until then what you see in this article is what I do and so far it works for me.