Coppersmithing a Coaster Part 2

Same 3 1/2″ starting disk.

This time I used a 3″ steel round, 3″ high, as the form. I trued it up in a lathe and then used a file to put a radius on the corner. The radius is vital when using a steel form, as it would otherwise cut into the metal. (When using the wood form, the sharp corners are going to mush anyways.)

I pre-bent the disk again. This really helps with centering because the slot bending tool is cut to the depth we want for the bend.

I only had to anneal the copper twice this time. The steel form really sped up the forging process and with more practice I might even get it down to a single heat.

Again I trued up the edge of the coaster using wet sandpaper over a steel plate. Glass or granite would have been better, but I have steel.

I then pickled the metal using vinegar in a crock pot, followed by a good scrubbing with Boraxo and a Scotch-Brite pad. Be really careful to not touch the metal with your bare hands after this point. The oil on your fingers can interfer with the patina.

I used Sculpt Nouveau smart stain. This is not a real patina, more like an ink.

In theory you can put it on cold with the spray bottle it comes in, but the spray bottle is crap and left a thick, uneven spatter instead of a mist.

After re-pickling the metal to remove the failed patina I tried again using the “warm” method. This time I heated the metal to 350 degrees on a hot plate before applying the patina (again, really a stain or ink) with an acid brush.

Looks good I think, but bits of the brush stuck to the metal. In fact, I think they melted on.

Lessons Learned

  • 3″ rounds from my metal supply house are not cut square. They are almost square, but that’s not good enough.
  • A Chinese mini-lathe can support a 3″ cylinder in the four jaw chuck, but it’s a pain in the ass to center it. Since neither the top and bottom are perpendicular to the sides, it has to float in the jaws. This means dealing with up/down, left/right, and the angles when trying to center.
  • I could really use a larger 3-jaw chuck. It would have eliminated half my setup issues.
  • Steel forms kick ass. I may focus my limited blacksmithing time on making more forms for coppersmithing. Especially stakes, which I don’t see making any other way.
  • 350F is NOT warm when it comes to stains and patinas. Rereading the instructions, “warm” is only 120F and “hot” is 180 to 220F.

Copper Coaster 2

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