Channels in wax

Someone asked about cutting channels in wax for princess cut
diamonds and the process for cutting the ladder formation at the
bottom of the channel. I didn’t have time to answer then and since no
one else has her are a few of my suggestions.

  1. cut the entire wax and do all the finish work before you start to
    cut the little square “windows” at the bottom of the channel that
    create what you called the ladder. I will refer to it as windows as
    this is what they remind me of. Make sure you are finished with all
    other work on the piece as cutting the windows will leave the wax
    even more delicate and prone to breaking.

  2. make sure the bottom of the channel is about 1 to 1.5 mm thick
    after the depth and width of the channel has been cut.

  3. Lay out the stones to go in the channel in the order you will be
    setting them and mark the centers on the edge of the channel with
    the knife edge of an exacto knife. Make sure the marks are light
    enough to polish out and well centered on each stone as this will be
    used to locate the drill point at the bottom of the channel.

4.I usually place all the stones on the sticky side of a piece of
tape at this point to keep them in order and not confuse which stone
goes where. If you are cutting a master model you can work from a
master stone that is the correct size to fit the channel and that
would be the ideal stone to fit the entire channel. ( as if you are
ever going to get all the stones cut the same to fit a channel, yea
right)

  1. Now after removing all the stones go in and using the marks on
    the channel locate the center point of each stone on the bottom of
    the channel with a needle point scribe.

  2. Next drill a pilot hole at each center point. As for drill bit
    size I usually use one that is just under the dimensions of the widow
    I wish to cut. If the window is to be a 2mm square I will use a 1.8
    mm drill. Remember at this point that you have to leave a narrow
    bridge between the walls of the channel that forms the sill of the
    window or the steps of the ladder formation and you must allow for
    this when choosing a drill bit size.

  3. I now take an altered exacto knife blade. I use a Swann-Morton
    BS2982 blade. This is a commercial blade that is sold in most jewelry
    supply houses and used for cutting molds etc. It is a straight
    tapered blade. Not the hooked or curved one. I alter the blade in the
    following manner. Using a seperating or cut off disk I cut down the
    length of the blade approximately .5mm above the knife edge taper and
    parallel to the knife edge leaving a long thin blade that is 1.2 to
    1.5mm wide with a tapered point of the original blade. Now cut the
    excess material on the back edge of the blade again using the
    separating disk. I cut at about a 45 degree angle to the sharpened
    edge and just forward of the slot that attaches the blade to the
    surgical scalpel handle. I use these blades in an exacto knife handle
    as opposed to a surgical handle. I use the round exacto handle that
    is shaped like a straight cylinder or pencil. I find the shape easier
    on my hands for long periods of cutting. I also make a second blade
    in the same manner but then cut the point off square to make a chisel
    point that is 90 degrees to the cutting edge of the knife edge.

  4. With these two prepared and altered knife blade I now begin to
    cut the windows. I start at one end of the channel and work toward
    the other. First I take a a sharpie ultra sharp fine point permanent
    marker that has a tip about .5mm wide and I mark between the drilled
    holes a straight line to represent the sill or step of the ladder
    formation. Placing the tip of the tapered point knife in the hole I
    proceed to cut away the material inside the window or square formed
    by the lines I drew and the walls of the channel. Cut from the center
    of the hole to the corner of the square going from corner to corner
    slowly enlarging the hole and making it square instead of round. The
    first hole is the easiest as there is no sill or ladder step to be
    careful of. The next hole is NOT as easy as the sill or step is very
    delicate and must be cut very carefully along that edge. I usually
    cut the sill or ladder edge last on each window as I go. This opens
    the hole up by cutting the other three sides first and as you are
    working on supported structure they are much thicker and less
    fragile. Also let me point out at this time and I will stress this A
    SLIDING BLADE CUTS and a PUSHED BLADE BREAKS. so slide the blade in a
    vertical motion as you cut and DO NOT try to cut by pushing the edge
    of the blade forward, rather slide the blade forward and let the
    knife edge do the cutting and not a chisel effect.

  5. after having enlarged the hole and brought it close to square you
    can now use the blade with the chisel point to square the corners.
    Place the tip of the chisel at one edge of the corner and carefully
    push down and chisel out a straight square corner. Be careful the the
    pressure is down and not sideways or the sill or ladder step will
    break. If cracking occurs or you break the sill or ladder step repair
    it with a small drop of wax on a hot tool and then re-trim. I often
    support the bottom of the channel at this point by placing a finger
    under it. If you are not careful you can cut your finger, but it will
    certainly make you more careful of the pressure applied and the depth
    you cut.

  6. Proceed to each hole in succession as you move down the channel
    and when you finish the last one work from the opposite or back side
    of the channel and again clean and square the windows. The same
    procedure works for cutting the channels for baguettes except the
    window shapes are more rectangular.

I am sure the next question is which wax to use and I always
suggest the wax that you prefer. I personally use matt wax purple
from the ring tubes. I have found that the older wax tubes in the
paper boxes are a better formula than the more recent ones in the
plastic boxes. I don’t know if they changed the formula or if the
aging of the wax makes a difference, but I noticed the difference and
try to buy the boxed waxes when and where I find them. I also have
found the slab wax to be different from the ring tubes. Go Figure.
Anyway that is my very large 2cents worth and I hope it helps. If
you need more info or clarification of some point you are welcome to
contact me off list at @frank_goss1. Frank Goss