Wednesday, June 3, 2009

Etching on Silver

Dan and I spent some time this weekend experimenting with silver etching using the E3 Etch controller. Here is the story with our findings, we are both pretty excited about the results. To start with, we are using a chemical called Silver Nitrate for etching silver. This worked better than other chemicals we tried and produced nice etchings. This is available in powder form and it is not harmful unless large amounts are ingested, so you have to keep this away from pets and children. It is extremely bitter, which helps that situation, but you should educate yourself on safety. The other caution is that it will stain your skin if you touch it. And I’m not kidding, look at my fingers! All I did was touch a few specs of it as we were measuring and pouring the crystals out of the container.

This won’t hurt me, but I am stained now for a good 2 weeks. I am shooting how-tos for a book right now with close ups including my hands, so now I have a lot of photoshop work to do. I suggest you wear gloves when working with it. Other than staining skin, it doesn’t produce fumes or pose an enviromental hazard in the small amounts we are using here. It is sensitive to light and air, so keep it in a bottle in a dark cupboard between uses. And, like the copper sulfate we are using to etch copper and brass, you can use it for a long time. With sterling, the solution will weaken over time as copper from the sterling dissolves into the solution. With fine sterling this shouldn’t be an issue. Simply strain it through a coffee filter and store in a plastic bottle-PET type (Marked with a POISON! label so no one drinks it).

To etch the silver, we mixed 10g. of silver nitrate with 1/2 liter of distilled water. The first piece we tried was sterling silver. The piece was sanding and then I wrote on it with a fine Shapie oil paint pen, it’s the little square that says “Dan & Sherri”. We etched this piece for 30 min on slow and it etched pretty quick. If left longer, the etch would have gone deeper. The silver etches about 3-4 times faster than copper does. The second piece was a PMC standard silver clay heart bead. This piece was originally overheated and melted a bit as it sintered so the outside was rough and bumpy. I wrote on this one with an extra fine Sharpie oil pen. I put a bent aluminum wire through one of the holes to suspend it and provide contact. I taped around the edge and sealed the back. I found it easier to “hang” the piece rather than using foam spacers because it didn’t have any sides to attach the spacers. Since it was a curved shape with a bumpy surface, I filled the the pan with enough etching solution to cover only the part I wanted to etch. The tape was used mainly to keep the piece level in the solution, and not as a barrier for the solution. We found that the wooden chopsticks did a great job to hold the wire. This piece was etched for 2 hours on slow speed. It was much slower than the sterling piece as it is larger and was suspened quite a bit higher from the bottom of the pan. When removed the metal clay has a very “crystaline” structure where the metal etched away. As soon as the piece was rinsed off and burnished the background was pretty smooth. I need to experiment more with PMC3 or + to see how they compare. This photo shows the set up for etching on the fine silver bead. Now that we have this figured out, I need to make some “wearable” pieces with cool designs.

PMC standard on left, Sterling on right

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