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Dennis
21-02-2012, 01:55 PM
Increasingly craft jewellers are turning to base metals for their work, but this raises the question of the colour of their solder. Rio Grande already have a gold coloured solder for bronze and brass, but there is only grey or silver for copper.
In an earlier thread, ‘The Colour of Solder’, I explored the possibility of disguising this by electrolytic means: simply dropping the piece into pickle with iron binding wire. The results were only partly successful, due to the thinness of the deposit. So prompted by PS Bond I researched the possibility of electroplating using a battery.

Materials And Method:
1. A ‘C’ size 1.5Volt battery was used for the power source. Round batteries are available in various sizes, all delivering 1.5 Volts. The difference is only in how long they will last. As there is nowhere to attach wires, I made a trip to Maplin and bought a one-battery battery box, which has terminals with holes to pass wires through and twist them. The wires I used were from some old flex and I added a spot of soft solder for good measure, but this is optional. I also bought two plastic sleeved crocodile clips which are crimped on.
2. For the plating bath I used a glass tumbler. A piece of copper sheet was hung from one edge by a wire. The test ring from previous experiments, stripped by heating and re-pickling, was hung from a thin piece of copper tube resting on the rim. The piece to be plated was connected by the black coded clip, its wire attached to the minus, or negative terminal of the battery box. The copper sheet to be depleted, was connected by the red coded clip to the plus, or positive terminal.
3. The electrolyte chosen was about 200ml of distilled malt vinegar. Nothing much had happened even after an hour, but after further research this was remedied by the addition of a pinch of salt and sugar: literally only a few grains of each.
4. Great care must be taken throughout not to let the two parts make contact, or there will be a disconcerting flash and the battery will be ruined. A good reason though to wear eye protection.

Results:
The ring was cleaned of loose brown deposit with a soapy wire brush at half hourly intervals and the result was thought to be acceptable after two hours. Unlike the electrolytic process in pickle with iron binding wire, electroplating is not self-limiting and could be continued for an even heavier build up.

Economy:
The copper sheet shows little sign of depletion, the electrolyte does not need replacing and my meter confirms that the battery has retained its full charge, even after eight hours of experiments
Dennis.

ps_bond
23-02-2012, 10:26 AM
I'm particularly interested in why sugar was used there, Dennis - I know molasses has a long history as a brightener in plating baths, but hadn't seen anything suggesting sugar alone could do it?

Electroforming is still on my list of things to do, although I'll probably stick to an acid/copper sulphate bath (with molasses that I'll pinch from the horses feeds!) - I have a couple of bench supplies where I can dial the current down to the low levels required.

As for preventing anode & cathode touching, I have a sheet of plastic mesh (from Hobbycraft, IIRC) that will reduce the risk without impeding the current flow unduly.

mizgeorge
23-02-2012, 10:43 AM
A quick look tells me:

"sugar is an organic intended to function as a brightening agent. Without a brightening agent, you grow large, soft, porous, crystals. The organic is drawn to the highest current density locations and clogs them, causing multiple smaller crystals to grow. Sugar is not a great brightening agent, but it's a safe one. Historically, molasses was used in production plating.....

Dennis
23-02-2012, 11:24 AM
Well, not everybody knows that. I just followed a recipe with no explanation and I presume that the salt improves the conductivity of the electrolyte. I have read that this idea could also be the basis for electroforming, if you spray an object with metallic paint.

Obviously this is a cheap and dirty method using store cupboard ingredients, and the safety of a small battery. Dennis.

ps_bond
23-02-2012, 11:27 AM
I have read that this idea could also be the basis for electroforming, if you spray an object with metallic paint.

I'm intending to mix some lacquer with powdered graphite to see how well that conducts.


Obviously this is a cheap and dirty method using store cupboard ingredients, and the safety of a small battery. Dennis.

It has to be said that my idea of store cupboard doesn't often tally with most people's...

mizgeorge
23-02-2012, 01:59 PM
LOL Peter. Nor mine :)

Petal
23-02-2012, 07:59 PM
Thanks for that Dennis, I've copied it to use later on.

Tabby66
23-02-2012, 08:53 PM
Very interesting!! Thank you all :)

Dennis
29-02-2012, 10:35 AM
It has to be said that my idea of store cupboard doesn't often tally with most people's...

LOL Peter. Nor mine :)

Oh you poor things.
You have surely cooked up a pickle or two
Or added balsamic to sauces and stews?
To endure without sugar is nowt but a …..r
And to live without salt is deprived by default.

armadillo
20-05-2012, 11:14 AM
This is wonderful Dennis - thank you for posting. Definitely one to print and experiment from!

july541
16-10-2017, 07:53 AM
Very interesting!

Dennis
16-10-2017, 10:09 AM
Not so interesting now. Brass and copper coloured solders are more widely available since that was posted almost five years ago. Dennis.

ps_bond
16-10-2017, 10:21 AM
Yet spammers are permanently on the rise.

josef1
16-10-2017, 11:11 AM
you cant have spam without salt and vinegar though !!!

ps_bond
16-10-2017, 02:07 PM
Actually, I quite like spam musubi. Sort of Hawaiian/Japanese fusion; no vinegar there.