Etching today.
I'm using Lascaux acrylic stop-out varnish as a resist to deep-etch a piece of approx. 2mm copper that will eventually be a plaque inset in a box top. The Lascaux is easily cleaned up with water while it's wet, and later on it can be removed with meths.
The mordant is "Edinburgh Etch", which is a combination of ferric chloride and citric acid. It's a lot safer on skin than nitric or hydrochloric, and it also bites fast and clean. Note: "safer" is a relative term; I still wouldn't go bathing in it.
It's a relatively warm day today, so I shouldn't have to go to all the faff of warming the bath. I'll probably have to etch for four to six hours to get the depth I want.
The tape is so that the back of the plate doesn't etch, and the chopstick rests on the lip of the mug to hold the plate vertical in the bath and to allow me to lift it out without touching it.
And now, six hours or so later, it's done.
The size is about 75 x 100 mm.
The etching really reveals the grain of the metal — not a grain in the way that wood has a grain, but gravity acting on the tiny granules of copper separated by the acid makes them slide down the face of the metal so the bite becomes uneven. There's also an element of uneven density within the metal itself, a relict of the way the sheets are produced in rolling presses.
No comments:
Post a Comment