1/2 June 2017
This workshop will teach two etching processes that can be used to etch at home or in a classroom situation, these are saline sulphate and electro-etching.
Both processes have been described as being ‘safe etching’ however in this workshop we will focus on their potential for alternative mark making rather than on their non-toxic credentials. Don Braisby who is teaching the workshop is completing his doctoral thesis on electro-etching.
Non-members £120.00/Members £75.00
Booking essential (via email or telephone)
telephone: 01978 267629
This zinc plate has been allowed to corrode all the way through in places. The original batteries made to produce electricity in the 1830s were made by hanging a plate of copper and one of zinc in a solution of copper sulphate. Thomas Spencer observed that copper was deposited on the copper plate (the cathode, negative pole) and that the zinc (anode, positive pole) was etched.He and John Wilson patented this process in 1840.
This plate was made by shorting out such a battery.
My research into electro-etching is based on the following testable assumptions that:
The objectives are to:
The aim is to:
In earlier scoping research for this project research saline sulphate was identified as a possible alternative mordant to nitric acid for etching. It is widely used and recommended as a safe mordant for etching zinc and aluminium (Wray). Ferric chloride was also considered, but rejected in the early part of the programme, owing to the difficulty of using it in a domestic environment. The benchmark that had been set for assessing an alternative mordent was that it should be inexpensive, safe and convenient for use in a home-based studio.
The conclusion of the research project was that saline sulphate could be considered as an alternative to, but not necessarily a replacement for acid etching or ferric chloride etching.
The major advantage saline sulphate has over nitric acid is that it does not require as many safety precautions. It does however share some of the disadvantages of both nitric acid and ferric chloride:
In 1991, Nik Semenoff at a conference, at the University of Saskatchewan in Canada, both described and encouraged artists to use electro-etching as a safe process to etch intaglio plates. It is a matter of surprise, that despite the fact that Nik made this claim twenty-five years ago, and the work of Marion and Omri Behr, Cedric Green, Alfonso Crujera, Bob Perkin and others have shown that his claims are valid, electro-etching is not in mainstream practice.
Current writing on electro-etching
Marion and Omri Behr (1993) published their research into the etching and tone creation in copper and zinc by means of a low voltage electrolytic process using the salts of the same metal as the electrolyte.
Cedric Green, working in France on an electrolytic process for etching copper and zinc he published his paper on galvanic etching in 1998, he has an active web site on which he publishes his and others artwork and researches into electro-etching and electrotyping. Cedric has recently added papers to his web site describing his concerns about the use of sodium chloride as an electrolyte because of its potential to release chlorine gas.
Alfonso Crujera an internationally respected Spanish painter, sculptor and printmaker began electro-etching in 2001 and opened the first electro-etching workshop in Spain in 2002. He published his ‘Electro-Etching Handbook’ in Spanish that has now been translated and published in English. Alfonso has an active website and runs residential workshops. He also has an easy to read, accessible paper on electro-etching on the non-toxic print website. Most recently Alfonso, in collaboration with Bob Perkin a U.K. based scientist, has been writing of their research into the science of electro-etching.
In 2010 Francisco Hernandez-Chevarria and Alberto Murillo published their paper “Metal Sacrifice: The use of saline (sodium chloride or table salt) to etch aluminium, steel and iron/mild steel.
Where am I at with this Project?
I guess the flip answer to that question is I wish I knew. I’ve probably learned more about myself than I have about the subject matter so far.
I am surrounded by a load of data; notes on experiments and ideas to explore further, but at a time in the PhD. Programme where I need to start pulling it all together into a coherent form and making some work. The making of work has been somewhat on hold over the past two years, so that is beginning to look like a priority. Using the making of art as a research tool.
 Howard, K. (1993). ‘Safe Etching and Photo Etching: The next generation’. Print Making Today, Vol. 2 No 3. pp. 19-21
 Same metal same metal salt describes the use of the same metal for both the anode electrode and cathode and the electrolyte being an aqueous solution of the metal salt i.e. an electrolyte of copper sulphate for copper electrodes and zinc sulphate for zinc electrodes.
 Wray, P. (2007) ‘Etching Made Easy’, Printmaking Today Vol 16, No 1 Spring, pp 25-25
 Semenoff, N and Christos, C. (1991) Using Dry Copier Toners and Electro-Etching on Intaglio Plates Leonardo, Vol. 24, No. 4 (1991), pp. 389-394.
 Electro-etching handbook: Alfonso Crujera: 9788493510091
 Printmaking Revolution – Amazon.com
This is an electrotype cast made from a ceramic model of the face of Buddha. The model is a Raku fired ceramic piece made by my father. I made the mould from general purpose RTV silicone rubber. The inside of the mold was given several coat of copper conductive paint and then placed in an electrolytic tank containing a copper sulphate electrolyte and a copper anode. The electrolytic process ran for 48hrs. at 0.5v and 1.30 amps. The casting is between 1.5 and 2mm thick. The head dress presented a casting problem in that the shape produced an air pocket that prevented the copper plating out. I have reversed the hanging fixture to get around this problem in the next casting.
This is not a how to do it!
Just a bit of fun.
This etching process was first described by Cedric green on his website and by Alphonso Crugera in his recently published Handbook. In this process the cell becomes a self etching battery.
When two metals with different potentials are placed together in electrical contact in an electrolyte, one metal will act as anode and the other as cathode. The electro potential between the metals is the driving force for the corrosion of the anode. Zinc has a potential of -0.762v on the index and copper +0.340v giving a difference of 0.422v. The anode becomes vulnerable when the difference is over 0.15v. Making the copper zinc coupling ideal for etching. This form of corrosion is also known as dissimilar metal or sacrificial anode corrosion. In a corrosive environment the metal with the lowest electrical potential (the zinc) becomes the anode in the cell and sacrifices itself for the more “noble” metal (the copper).
The etch on the plates is very deep and is great for viscosity inking.