Twisted Copper Inlay Experiments #1

So I've been distracted again by a shiny object, this time it is copper wire inlay.
A few projects have been posted lately with this technique so I decided to try it out with some basic crosses



These are #12 AWG copper wire, twisted, with blue mica colored epoxy in walnut.

I wanted to cut deeper into the inlay and see what pattern can be exposed. I really liked the "string of beads" that showed up when cutting almost 1/2 way through (top photo, beads in oak).

This short blog follows on my as yet to be tested process to get some nice bead strips for future projects.

For this test, I'm using some scrap #10 AWG copper wire.
About 72" of straight wire, x 2 pieces, twisted up with my drill on one end and the other ends secured into a vise.
Yield is 36", about 1/2" of the original length.

I wanted a section of counter-clockwise and clockwise twists so I can get symmetry for various uses.

To get the twist density about the same on both sections, I set the clutch on my drill to slip when the twist was tight enough.



These are the wires cut in half so I have four 18" sections, two CCW twisted, two CW twisted, sitting on two squared and flat 4" wide walnut sections.

You can see one twist has a silver tint. I tried to solder it thinking I could get some interesting effects when finished, but this really went nowhere so fugetaboudit 8^)

For the expoy, I have some vintage 10 year old cans of West Systems with the 207 hardener, a low viscosity hardener that makes this stuff really flow out.



These came with the dispensing pumps, but the hardener can pump died so I went with a "by weight" mix.
Hard to believe this kit was about $60 at the time which I though was expensive. I see they are up to about $130 now (ouch!)

I will use two colors, one board with blue mica and the other board with TransTint "Perfect Red".

Slotting the boards

The twist has a diameter of .190" so that is my target slot width.
To get a consistent pattern, the wire needs to be flat across the entire board. For this to happen, I cut a slot that is 0.150" deep, leaving a slight amount of the wire above the slot so I can use a caul to press it in and bottom it in the slot.

The boards are covered with masking tape to keep sloppy epoxy from soaking into the grain.



A FTG rip blade does the initial cut (cut a slot, rotate the board, then cut another slot). Measuring the slot width tells me the slot needs to be 0.060" wider. I use a dial gauge on the fence when I need to adjust like this, quick and accurate, plus I already have a selection of these measuring tools to select from.



Slots are an excellent (snug) fit.


For my tests, I want the wire to be secure from shear forces and not have any ends that could pop out and catch on anything. The answer here is to bend the ends of the wire and insert them into holes drilled into the slots.

First I bend down the ends with one of my cheap-azzz dead soft HF punches, glad I didn't toss these years ago!



Next the holes are positioned and drilled, a small radius is cut in with a tiny carving gouge to allow the wire bend to sit flush.


The back side of the holes are taped to keep the epoxy from leaking. Small strips of hard board are also inserted into the slot ends to act as dams.


Pour the epoxy

I fill the slot to slightly below the top with the mixed epoxy. These two slots required about an ounce of mix (that is one of those 2 oz. condiment cups)


The wires are placed and pressed into place, then covered and back filled with more epoxy.



More masking tape is laid over the top to keep it from the caul as much as possible.



the cauls are 3/4" melamine, waxed. These are hard enough so that the wire will not make a dent when they are used to press it into the slot. A chunk of oak is used to back up the melamine.



You can see the gap between the caul and walnut, this shows that the wire has bottomed out in the slots and should make for a nice, consistent pattern.


The other board went the same way except I used the red dye (three drops).



A bit more translucent than I had hoped, but I didn't want to over-contaminate the epoxy.

Clamped and set aside to dry.


Next installment I go into the real part of this experiment, all has gone well enough so far.

Thanks for following along!

Note" Part #2 is now here