Electro Etching of Silver

By John Flynn

Here are some recent experiments with electro etching of silver using Ospho brand phosphoric acid diluted 50/50 with distilled water and using a very old plating rectifier. These pieces are all sold.

The resist is sign vinyl. The pieces are mostly etched at 1 volt for 1 hour. Some of the pieces pictured here are etched at 1 volt for 2 hours. Frankly, I don't remember which is which. The one piece etched at 5 volts for 1 hour is noted.

Ospho is available at True Value Hardware and probably many other sources. It is used as a rust stopper and as far as I know it is relatively non-toxic. The active ingredient is phosphoric acid which is what gives Coca Cola most of its "bite". I haven't tried it yet, but you might be able to use Coca Cola for this same process.

My High Tech modern rig.. This is an old Vigor plating rectifier and an old stainless steel fish steamer. The steamer is my cathode (-). The piece of jewelry is the anode (+).

This is the configuration that worked the best for me for these pieces. Sparkie two sterling ear posts on the back of the piece, punch out two holes in the vinyl to match. Block out the diference with clear nail polish. Cover the posts with rubber plating sleeves and insert 21 gauge niobium wire for the connection to the rectifier. I once made the mistake of using 21 gauge sterling wire for the connection and watched it etch right through.

This is how it looks when I etch. That is an old fiberglass tent pole section, a wooden dowel would work fine.

Fine tuning the voltage.

Here is one of the pieces at 1 volt, 1 hour with the vinyl still on, cleaned up a little with a nylon brush. At this point I decide whether to leave it as is, tumble and polish, bead blast, etc....

This design is a family symbol that I etched for an actual Polynesian Princess from New Zealand. If you rip it off you will be killed in the most horrible fashion, cooked and eaten. By me. The Polynesians are way beyond this kind of thing.

I did four versions of it for her family. Here are two of them, positive and negative.These two were done facing down in the bath at about a 45% angle to allow the bubbles to rise away off of the etched area. The recessed areas were bead blasted, after etching, with 80-120 grit glass beads at 60 lb. from a pressure pot blaster while the vinyl was still on.

Here is one done facing straight down with no vibration. The little points are caused by bubbles from the etching process. Very interesting but uncontrolable.

Here is a nice effect. This was done sitting in the bath at a 45% angle with an aquarium pump taped to the outside of the tank. This is one of Karen Christian's discoveries. The pump provides vibration, no air. In this case it caused a standing wave patten and parallel lines that looks like the piece was milled instead of etched. The recessed areas were bead blasted after etching with the vinyl still on.

Here is a close up of a money clip etched with a Hawaiian petroglyph of a turtle done for 1 hour at 1 volt.

This is a strange and certainly worth exploring effect. 5 volts for 1 hour in 100% Ospho.

Here are some pieces with a Celtic design needing a final clean up.

Here is a little experiment with 14K, 100% Ospho and 5 volts. This generates enough heat to burn off the resist but it does work to some extent.

If you are reading this you are probably a member of the Orchid Group. There is nothing else like this on the planet. Hanuman and Charles have created a new paradigm. This is what the web promised to be and rarely achieves. Where else do you get this kind of information?.

Thank You,

John Flynn