Sunday, May 18, 2014

Awkward Bezel Setting

In the beginning there was a snail operculum (that's door to us laypeople).  And this shell wanted setting, because a client paid me to do so.  However, I have never set an awkward shape or sheer size like this - asymetrical yes, but not where one side is twice as thick as the other side with a bulky bottom sticking out.

At 2.5 cm x 3.25 cm (1 in x 1.3 in), the shell will test my silversmithing skills.  So I charged less to the client, as I typically do when a project will push my boundaries and give me a chance to learn new skills.

Please note:
This is not a how to on creating a bezel setting in silversmithing, more the journalling of my boundary pushing steps.

No settings below have been cleaned up.  This is the deep and dirty of silversmithing.

Try #1 Back

Bezel setting attempt #1 

3 mm tall 0.3 fine silver bezel strip
2 mm round silver wire as backplate
Hard solder 

Lately, I have tried to scrimp on silver by using thick wire flattened as the base plate.  This has worked well on the smaller (under 10 cm/0.4 in) stones I have set.

I also assumed a 3 mm bezel strip would be enough to trap the sides (both thick and thin) provided the back plate is thin enough to just catch the thicker side.

I have not soldered such a large expanse of silver before and use a mini torch on butane gas.  I went through 2 full fills on the torch tank before I realised the silver was too big and the fire proof ceramic tile was sucking the heat away from the solder.  Out came my broken charcoal block after remembering where I'd stashed it after a flash back to early lessons. 

Try #1 at side
I quickly re-discovered the miracle of soldering on top of a charcoal block rather than ceramic.  The block bounces more of the heat back onto the larger bezel setting! (Yes, I can hear the "well duh" coming through).

Finally all of the solder had melted and the bezel was stuck down.  I used a LOT of solder, too.  All looked good until the last minute when the bezel seemed to do a slight readjustment movement.  Didn't think about it though.

Offending base plate wire sticking up
 After turning off the torch and quenching the piece, I spent time cleaning up the outside of the bezel.  Only, the shell wouldn't sit in the bezel like it should.  On closer inspection of the bezel, I noticed that the wire end I had flattened and used as the back plate had twisted and now stuck up the side of the bezel wall - creating a bump.

In the land of the well tooled I am sure there is a dremel attachment that would, with patience, grind it away, but I noticed that unless I completely shave away all of the backplate, the 3 mm strip was too short to catch the larger side.

Oh boy.  Start again....

Try #2: The Ring

Flattened back plate
 5 mm fine silver Bezel strip
2 mm sterling silver round wire as base plate
Hard solder
planishing hammer

I made the bezel strip around the shell and set aside.  Next the 2 mm round wire was made into a circle that fit exactly under the bezel strip.  

In theory I hammer it flat slightly and the bezel strip should sit smoothly on top with a bit of lip inside and outside of the bezel wall to act as the back plate, as works for the small stones I have set in the past.
Too Big

Note to self, there is such a thing as too much aggression therapy session on the hammer whacking away on the wire.  My wire ring grew so much (with my planishing hammer) the inner diameter of the oval was bigger than the outer diameter of my bezel strip.  Woops.

I did not even bother making a new one and went upstairs, calling it a day.

The bezel strip was left for a third try.

Try #3: The Almost Right

5 mm fine silver bezel strip (already prepared)
1 mm thick sterling silver sheet for backplate
hard solder

Third time is the charm, right?  You would think so.  

Going back to basics, going old school, doing it the right way from the start.  Solder bezel to plate, cut plate out, cut middle out and done.

Try #3 Looking Good

The prepared earlier bezel strip was soldered to a large plate of sterling silver sheet. I put the whole thing on top of the charcoal block and the solder melted beautifully to that mirror glint at the seam of strip/sheet.  Normally, it is suggested to make the back plate as small as possible so to not heat up unnecessary.  I did not remember this of course until after I looked at the expanse of silver that required removal.

I was so happy and full of glee!  Everything working to plan.  A few hours later, said tongue in cheek, the bezel setting was released from the rest of the sheet metal with my coping saw. Forgot how tough 1 mm silver sheet is!

Try #3: Sides cleaned up
I used my ... um... wooden joint wedgie thingie (yes this IS a technical term in my workshop).  Just did a search, it's called a Ring Clamp with wedge.  So my term isn't much worse in verbage.  Anyway, I used the ring clamp to pin the bezel setting down tightly enough to file off the back plate lip even to the strip, leaving a seamless cup from viewing on the outside.  

Took a while and kept forcing the wedge a little too tightly so it bent the bezel strip down quite a bit.  But the outside looked beautiful sanded down with 280 grit sand paper when finished. I used pliers and other rounded objects to coax the bezel strip back into a good shape and it still fit the shell! 

Try #3 Back

The centre was punched lightly and the drill press put into use to make a hole in the centre of the back plate for my coping saw.  I have decided I am not very fine tuned with this tool either (out of practice mostly) but I got a relatively even looking oval cut out which required MORE sawing for the back of the shell to stick through. 

Try #3: Setting almost finished

When the outside was filed away and the back plate hollowed out, there sat the perfect bezel setting for the shell.  Just needed to file a little deeper in the back plate on one side.

Try #3: Cracked Bezel
And inspected closer to notice... the bezel strip had been worked so much by the ring clamp squishing down that it has split and crumbled in my hands.  And not just a small split, but 2.5 mm deep split that brings the lip below where the snail shell will lie.  Absolutely no way I can save this setting for this particular shell.

I tried to make the back plate shallower for where the thicker side sits, but it will not make the bezel sides even - even if I can get it to sit lower.  And a bezel slightly taller on one side than the other will be noticeable.

Words cannot say the amount of frustration here!

Try #4: Hopeful Success

Try #4: Bezel Strip Soldered
5 mm x 0.3 m Bezel Strip
0.5 mm sterling silver sheet
5 mm ID x 1 mm sterling silver tube (bail)
Hard solder
Easy Solder

A new bezel strip soldered was crafted - but at last minute the ends overlapped just as the hard solder flowed.  Just kept moving forward.  Carefully forming the strip around the shell again, the overlapping became a bonus because the ring fit perfectly. 

Back on top of the charcoal brick, the bezel strip soldered beautifully onto the thinner (and pre-shaped) back plate within 1 torch tank worth of butane.  Hard solder flowed to the mirror flash all around, ensuring a solid and firm attachment.  At this point, I went upstairs calling it a day.  Didn't want to test the luck too much!

Try #4: A light trim
A few days later, it was time to cut the back plate excess away with the coping saw and file down the resulting lip.  The 0.5 mm thick sheet cut like butter with the coping saw compared to the 1 mm thick so I was able to control the saw much better.  I did not use the ring clamp (with wedge) at all this time around.  That bezel strip is going to be pristine when it comes time to setting.

The filing took quite a while and a lot of elbow grease as I took it easy with a light touch.  Using a small fine metal file, I removed the bulk of the lip and then moved down to a paddle pop stick wrapped with 280 grit sand paper to do the fine filing and remove previous file bite marks.

Try #4: Front Shot
Time was spent with the Hasbras rubber wheels and dremel to really smooth out the file marks from the side of the bezel.  I used the drill press to make a hole into back plate then moved to the coping saw again to cut out the inner oval.  Try #2 pendant was used as a template for the oval hole.

The shell was used in place to test and fine tune the back plate hole until the shell sat with a consistent 1 mm lip all around under bezel edge.  Now time for the bail tube.

I used a right angle level to make sure the bit of tube I cut out was mostly square on both ends (and filed out a few skidding coping saw marks).  Easy solder was sweat soldered to the middle of the tube and then centrered onto the top bezel strip seam for final soldering.

At last minute I decided to add just a smidgen more of easy solder on top of the join, just in case.  The two pieces stuck together nicely with a bit of flux and the solder flowed beautifully.  Glad to see things working right!  Unsure if the bail is a little sideways, and really not fussed at this stage.

Try #4: Side View
Try #4: Back View

Pendant is pickling and still needs setting and final polish. But it is done!


Anonymous said...

Good on you for persisting. It looks wonderful

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