It’s DONE! Making My Brother’s Wedding Rings 6: The Finishing

This is where the rubber meets the road in the jewelry-making process. Finishing can make or break a piece.

With casting, if care is taken with the wax (ie. making sure the wax if very smooth, free of nicks and scratches, and nice and even) then your finished piece will be that much easier to clean up.

I’m going to be very meticulous with the finishing here, because I really want these rings to be beautiful and shiny. They are, after all, wedding rings, and need to be extra special anyway!

Check out our starting point:

Gold rings direct from the casting flask and ready to polish.
Gold rings direct from the casting flask and ready to polish.

First step in finishing; filing off the remnants of the sprues. We’re left with hearty balls on the band after the casting; and its no easy task to file that down with hand tools to make the bands smooth and even again. The goal is to make sure one would never know it was there. That takes some time, and some elbow grease.

I save my gold filings for use in future projects. It may seem like overkill to keep gold powder/dust, but it adds up for future use.

Bubble left on the band from the sprue.
Bubble left on the band from the sprue.

Once the band is even again it gets a nice light sanding. I used a Foredom tool with a coarse then a fine sanding drum to make the work easier. It cleaned up it very nicely.

Once the sanding is complete; it’s over to the polishing wheel for a liberal coating of Tripoli compound; a waxy paste that is mildly abrasive. It can quickly and easily remove the fine marks the sanding has left, and is the first of the polishing steps to ensure a mirror finish.

Tripoli compound being loaded into the polishing wheel.
Tripoli compound being loaded into the polishing wheel.

After the tripoli does its work, the rings get a quick scrub in soap and water, and then on to the second phase of polishing compound; Red Rouge. This is where the rings buff up like a dream. A few minutes under the rouge wheel and they shine.

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Another quick scrub up, and….. they’re done.

It’s been months of slow work (I had the privilege of being able to take my time with these) but I’m VERY happy with how they turned out. This work could be done in just a couple of days, but it was also a learning process for me I had no desire to rush. It also helped that my brother asked me to do these last fall.

The wedding is July 27th. I hope you’ll join me in wishing the newlyweds-to-be a lifetime of happiness … and great looking jewelry.

Shiny!
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Love it! So shiny I can see the pattern of my phone case in the ring!
Love it! So shiny I can see the pattern of my phone case in the ring!

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Making My Brother’s Wedding Rings 5: Casting Part 2

So last night we made the moulds (see Part one of the casting blog for that).   Tonight we’re liquefying gold and turning it into rings.

If we’ve done a good job at the spruing, investment, and kiln drying; this is the fun and easy part.

First steps; prep the equipment.

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We’re using a centrifugal casting set up, which consists of a large drum (to protect you if your flask explodes with hot metal inside), a crucible (where the metal gets melted down), a cradle for your casting flask or your mould, and a spinning arm which gets wound up like a top, and has a brake put on until you’re ready to go.

Heating the crucible
Heating the crucible

We heat the crucible first, to help lower the time it will take the melt the metal.  Once it’s piping hot, the flask is removed from the kiln, wired into the cradle, and the crucible and flask are pushed together.

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Removing the casting flask from the kiln
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Wiring the hot flask to the arm.

More heat is applied to make sure everything is warm, and the metal will flow freely.

Then it’s time to add the gold (good bye old unworn gold, hello new, shiny wedding rings!).

The collected gold, about to become shiny and new.
The collected gold, about to become shiny and new.

It’s all piled in and heated until it’s 100% liquid; Teacher Trevor checks the molten goodness for lumps of unmelted metal, which could not only wreck your pour, but could also cause the flask to explode.  (Thank goodness for that drum!).

FIRE!! (in the crucible)
FIRE!! (in the crucible)

Once Trevor is satisfied everything is a go, he releases the brake and centrifugal force takes over; sucking the gold deep into the flask so it fills everything.

Brakes OFF; the arm spins around, using centrifugal force to pull the metal in.
Brakes OFF; the arm spins around, using centrifugal force to pull the metal in.

The arm spins for a couple minutes, then the flask is left to cool off a bit before quenching it in water.

Gold peeking out the top of the "funnel" part of the casting flask.  Cooling before quenching.
Gold peeking out the top of the “funnel” part of the casting flask. Cooling before quenching.
Quenching the flask in water.
Quenching the flask in water.

The water begins dissolving the investment almost immediately and it crumbles out of the flask.  We hear a soft ‘plunk’ as the gold rings fall out and hit the bottom of the quench bucket.  Trevor fishes them out and….  Boy, do they look rough still!

Still a bit chalky from the investment...
Still a bit chalky from the investment…
Cleaned up but still not pretty & shiny...

So what’s a sister to do?  Part 6 (and final part): Finishing.

Ready for the FINAL step: finishing.
Ready for the FINAL step: finishing.

Making My Brother’s Wedding Rings 4: Casting Part 1

Now the action begins.

Casting is a 2-day process and it starts with prepping the wax rings by attaching sprues; essentially little hoses, which will attach to a wee wax funnel where the molten metal will flow in.

Attaching the sprues with a hot wax pen.
Attaching the sprues with a hot wax pen.

The sprues are attached using a drop of hot wax.

Sprued rings, ready for the flask.
Sprued rings, ready for the flask.

Once that’s done, they’re fitted into the base of the casting flask, and its measured to see how much investment is needed.

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Investment is an almost plaster-like substance, which fills up the flask and covers the wax rings.  It’s then baked in a high heat kiln overnight. The wax rings dissolve, leaving perfect little hollows, shaped exactly like your rings, and with any and all detail.

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Making and mixing your investment is a specialty all to itself.  Trevor, my jewelry instructor of a few years is an expert, and he’s doing the bulk of the work here, and humouring me by letting me “help”. It’s a great learning experience for me; but I’d definitely be in over my head if I had to try this myself.

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The investment power can be toxic, so wearing proper protection is a must.

Meaasuring the investment powder and using distilled water are also essentials.  Trevor is also adamant that the mixing technique is precise; using gloved hands to feel for any lumps (just one could cause your new plaster cast to explode in the kiln, or when pouring the gold), and timing the mixing exactly (we have 9 minutes to mix and pour and vibrate the flasks.

Hand-mixing the investment.
Hand-mixing the investment.

Vibrating removes any air bubbles inside which could cause similar unhappy endings to a casting flask, and thus all your hard work.

Vibrating the investment to remove air bubbles.
Vibrating the investment to remove air bubbles.

Once the mixture is just right, it’s carefully poured into the flasks and left to dry for a few hours.  After that it’s straight to the kiln.

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Finished flask from the top.
Finished flask from the top. That little “scoop” is the funnel that we’ll pour the molten gold into.

Once the flasks have been fired for the appropriate time, they’re ready for the next step; melting down the gold and pouring!

That’s tomorrow….

One post-script on this:  this is by no means an exact step-by-step of the casting process.  Casting is a very specialized, very delicate and sometimes dangerous process that should only be done by the experienced, or under proper supervision.  This is my journal of the process of making my brother’s rings, so please, don’t read this and try it at home!