KEN BROWN ENGRAVING’S FIRST ENCOUNTER WITH COBALT CHROME.

The bride-to-be had seen my wine bottle engraving at a Market Street event several months ago and tucked that idea away for her upcoming wedding.  Last week she brought me the groom’s wedding band and an AR-10 Nato battle rifle to be engraved.  He’s a Dallas cop so that explains that, though the AR-10 is not department issue.

The ring was made of cobalt chrome, an extremely strong, hard alloy of the two metals.  A round carbide bur wouldn’t even put a scratch on the surface so I had to resort to a #3 diamond bur I hadn’t seen or touched in almost 20 years.  It did the trick quickly and effortlessly.

The problems working on the inside of a ring include holding it, lighting it, and seeing it.  Not minor issues.  I held the ring between thumb and index finger with my fluorescent lamp adjusted above and in front of the ring, about eye-level where I was sitting.  After every letter, the ring is turned just enough to do the next letter.  Keeping the baseline evenly spaced from the edge of the ring, leaving room for ascenders and descenders can be a genuine challenge.

The ring was $500. retail and I didn’t charge enough because I didn’t ask the value before I quoted the job.  If I botched it, I would own it and have to buy another to replace it.   But I did it as she requested, no mistakes, and she was thrilled. Nevertheless, I still got a nice fee for 6 minutes work on the ring.

As for the AR-10, the metal was a different animal. It was black and extremely hard on the surface. I began with a used bur and it barely scratched it.  Swapped that for a brand new #3 round and it took less pressure to make it cut but still difficult. When trying to make it cut a deeper path, the metal felt like stale cake icing…hard on top with a mushy layer beneath. Hard on the top but with a little more pressure, the knife (drill) would sink. In the first letter with the new bur, I let the pressure get a bit too much and the bur made a shallow hole and wouldn’t continue the motion on a loop of a descender. I managed to blend the hole into the stroke but the rest of the 3 lines were difficult and not my best work. Extremely hard to control the drill in such material and I have no idea what it is or how to know the next black metal on a gun is the same. This was the second time for the problem in a year or so.  No photos taken, though I should have for future memory-jogging.

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The photo below shows the #3 round diamond bur on the left compared with a #4 round carbide on the right.

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The bride’s two items mentioned above are rare and not the every day typical items I see and engrave.  Still, even under-pricing both, I earned a nice fee for 30 minutes work.  Had that half hour been spent on wine or spirits bottles…or crystal or china or stainless steel knife blades, the nice fee would have been even nicer.  By about three times.

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3 Responses to KEN BROWN ENGRAVING’S FIRST ENCOUNTER WITH COBALT CHROME.

  1. Jose Valencia March 23, 2015 at 2:43 pm #

    Hi Ken,
    I engraved a name and a logo on an AR-15, and I ran into the same problem.
    Those type of rifles have a special coating that is baked into the metal, which it great for protection!
    I ended up doing the name by making it wider and using a stippling technique.
    Same method used on the logo.
    It took longer to engrave, but both came out really nice!
    Keep up the good work!
    Jose Valencia

  2. Mary March 27, 2015 at 1:41 pm #

    Hi Ken,
    How did you know the ring was made of cobalt chrome? Was the bride able to give you that information or was it stamped on the inside of the ring. Just curious how to identify what type of metal you are dealing with before trying to engrave it.

    Thanks for info!
    Mary

  3. KenBrown May 19, 2015 at 12:20 pm #

    Both. She told me and it was stamped.