Accurate piercing

[Didi]

I have a little half sphere that I want to pierce out to leave a lattice pattern. What do people use to mark the metal where they want to cut? on flat sheets I use a sticker that I've drawn on but it won't work on the sphere. I've tried drawing direct on the metal but it just smudges as I handle the piece. I guess this question should really be directed to James who, in my view, is the acknowleged master of piercing. Any help would be much appreciated though.
Thanks in advance

[Goldsmith]

Hi Didi,
Here is my method of marking a lattice pattern for piercing on a half sphere. I use a pair of dividers like these; http://www.cooksongold.com/Jewellery-Tools/4-Dividers-prcode-999-571 and some simple geometry methods. I first find the centre point of the dome and punch a mark in the centre. Then I divide the circumference of the into equal sections as to the size of lattice I want. Then I use the dividers to mark arcs from the centre point to the marks around the circumference. You can practice this method with a compass and a circle on paper. As with most methods this is easier for me to show than explain.
I used this method to mark out the lattice work on this egg, the top half or the egg is a sphere.
James

3195

[Goldsmith]

Didi,
If what I have said is not useful, then let me see what design you wish to mark out and on what size of sphere and I will let you know in more detail how I would do it. I have a few other tricks that I use when marking out piercing patterns on dome shapes.
James

[Didi]

Hi James
The sphere is 19.5mm diameter and i would like to have an even number of points at the edge. 6 or eight would be good. I think if I try for more the solid bits will just be too thin and although I am not too bad at piercing I'm really still a beginner
Many thanks
Didi

[Didi]

Sorry James, that was not the most helpful reply. I am wanting to do the same pattern as you have done on the egg.
Didi

[Goldsmith]

Didi,
Your half sphere is smaller than I imagined, I think if I was making such a small thing I would try piercing the lattice pattern requirements on a flat disc and then use a doming punch in a dome block to shape the pierced disc carefully into the required half sphere.
Another method that I use to draw patterns onto shaped surfaces is to first polish the shape, then degrease it and paint the polished surface with white poster paint, let it dry and then draw my design on the painted surface, if you make mistakes with the design just add fresh paint and start again. When I am satisfied with the design I gently draw over the pencil design on paint with a scriber point and when done, wash of the paint and the scribed lines will show up well against the polished surface.
good luck, James

[Didi]

James
I did think of piercing it first but then I worried about the pattern distorting. The paint idea is sheer genius, I happen to have some vinyl emulsion handy from decorating. I think the vinyl emulsion will just peel off when Im done, also I can probably use and eraser on the pencil. Thank you so much. I will let you know how I get on
Didi

[Didi]

Hi there. Thought I ought to let you know how I got on. Here's the finished piece. The case was pierced ( using James' excellent method), I attached a tiny hinge (much swearing), threaded a glass bead so the whole sphere would rotate and made a bail. The chain is viking knit and the clasp is a lentil clasp which I made using the same technique as the sphere. Many, many thanks James, your work is inspiring.
Didi

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[MeadMoon]

I am seriously impressed Didi, that's just gorgeous! I can see why the hinge might have been fiddly, but the result is well worth it.

[mizgeorge]

nicely done :)

[snow_imp]

Didi - that looks so amazing. Congrats.

[medusa]

oh that is lovely! I'm dead impressed!

[ShinyLauren]

Nice piercing - that's a lovely necklace!

[caroleallen]

Lovely work.

[Goldsmith]

Well done, now what's your next project?

James

[Didi]

Why, thank you all for your kind comments. It was a bit of a learning curve. James, I'm now working on a set of about 9 lockets for my sisters and nieces. I want them to look like stained glass windows Here are the first ones in construction. Just thought, I would really like to hide the hinges inside instead of them looking all 'clunky' outside. Any tips would be gratefully appreciated.
Didi
3794

[Goldsmith]

Didi, it's not easy to explain how to make what we call a hidden joint (hinge). To do this job successfully you will need a joint file that is the same diameter as the tube you are using for the hinge. There are two type of joint files available in many diameters and cuts. The most popular one used in the trade are like parallel round needle files, there are also ones that are like flat files, but with only teeth on their half round cutting edges. Then you will need to solder what is called a bearer wire on the inside of the bezel where the hinge will be and use the joint file to file a groove in the bearer wire to take the tube.

Take a look at this apple that I made, it has a hidden joint / hinge, it might be easier to see what I trying to explain.

James

3795

[Didi]

James, I think i understand. You have to make a platform to take the tube, file it to fit the tube and then set the tube on that. Ive been making the hinges in one go by using oiled wire to keep them aligned , very little solder and tippex as a resist. Am i right in thinking i would have to make the hidden ones in 2 goes - i.e. box first then lid? Where can i find joint files - my tubes are 1mm internal diameter. Love the apple.

Didi

[Goldsmith]

Didi, I have had a look online and am surprised that the UK jewellery tool supply shops do not stock many joint files.
Cookson only list this one; http://www.hswalsh.com/Needle-File-.aspx?i=TF8132&c=248
H S Walsh offer this type but they do not specify what size they are; http://www.hswalsh.com/Needle-File-.aspx?i=TF8132&c=248
Otto Frei in the USA stocks the type of joint files that I have; http://www.ottofrei.com/store/Round-Parallel-Hand-Files/

When I make boxes I make the box and lid at the same time so that they fit together perfectly, then I add the joint. I also use what we call a joint tool for filing the tubes, this ensures that you have a tight fitting joint; Cookson sell these; http://www.cooksongold.com/Jewellery-Tools/Joint-Filing-Tool-prcode-999-596

But I made my own joint filing tools way back when I was an apprentice.

James

3796

[Di Sandland]

Interesting James - I have enamelled boxes running round inside my head at all hours of day and night!

[Goldsmith]

Interesting James - I have enamelled boxes running round inside my head at all hours of day and night!

Hello Di, if you like enamelled boxes then you will love this one. It was one of my antique restoration jobs, a pendant vinaigrette in the shape of a book.

James
3797

[Di Sandland]

Oh, wow! James that is absolutely stunning - right up my street that is. I've just been in the second hand bookshop and bought a couple of tomes on the history of enamelled boxes. It's official - I am in the grips of an obsession