If you recieve a silver item from shapeways, you may find it too bright and glossy.
Using electrolysis is an easy way to make the silver darker so it gets more contrast and an "ancient" look.
In my opinion, the technique is pretty harmless, but please be aware that you're doing this at your own risk!
What you need:
- Old Spoon
- Old AC/DC power supply or power transformer
- Baking Soda
- Glass of water
1. Dissolve baking soda.
Dissolve some baking soda in a glass of water. I've used approximately one teaspoon of it for 400 ml of water.
2. Prepare the power supply.
I would recommend a 6-12 volt power supply with 500-1000 mA (=1 Amper). More amper would make it work faster but this is where you enter the "danger zone", so I wouldn't use a stronger power supply for this project.
Make sure the power supply is "DC" and has a cable that's long enough (about 1 m).
If there is still a plug on the supply, cut it off and remove the insulation on the two wires. Now it should look similar to the one in the picture.
To check which contact has "plus" and which one has "minus" just plug in the power supply and put both wires in the glass with the water and baking soda.
Make sure that the two wires are separated from each other. A contact could damage the power supply. After putting it in the water, you'll see that one wire is turning dark. This is the "plus" wire. There should be bubbles coming from the other one. This is the "minus" contact.
The best thing is to mark the "plus" wire with some tape so there won't be a mix-up.
3. Put everything together.
Make sure the power supply is disconnected. Connect the spoon with the "minus" cable by wrapping the blank wire around it. After that, do the same with the silver item and the "plus" wire. Put the connected spoon and the item in the water and keep them separated from each other. Plug in the power supply and enjoy the show.
4. Check the silver item.
You should stop the electrolysis after a minute to check if the silver is already dark enough. Make sure you disconnect the power supply first. You should clean the silver with e.g. an old toothbrush. This also ensures the electric conductivity to the wire.
If it is not yet ready, put it back on the wire and turn on the power supply again.
I usually do this 5 to10 times till the silver is kind of black.
5. Polish the silver item.
A black silver item isn't nice at all. The embossed parts should be polished now so these areas are becoming glossy again. I use fine sandpaper (800-grit) for this.
After this, it should look similiar to the picture at the top.
Helpful links:
https://en.wikipedia.org/wiki/Electrolysis
https://www.ighunters.net/metal/electrolysis/equip.htm
https://www.mycoincollecting.com/collecting/cleaning-coins-el ectrolysis.html
Please let me know if you know how to improve this technique.
Have fun!
Michael