Category: exhibitions

project sparrow complete

project sparrow (working title) | copper & vitreous enamel | 2016

my main concern is holding the book together. the weight of the combined pages is a lot to hang on tiny copper jump-rings. 2 rings per hole gives flexibility to allow for irregularities in positioning the holes and page size. they all start the same but extensive etching and repeated firings wear away some of the edges.

project sparrow (working title) | copper & vitreous enamel | 2016

overall i’m about 80% happy with the finished result. my intention was to show a gradation in depth of colour across the pages – from dark to light on the text side and light to dark on the reverse – which was only partially successful.

front cover

i’m very happy with the text transfer process, but the wing resist on the reverse is much subtler than i hoped. but it was really important to me that i made use of the actual wings and feet in the finished piece. the feet on the front cover have great contrast and a contouring that reflects the use of a physical resist.

text side

i had to rework the wing section when i realised i’d done it in the wrong order. i’d already spent several hours stoning back the text sections to bring out the bright copper of the etched text, and while the repeated application and removal of enamel layers has a certain zen quality and makes for a pleasingly complex texture, it certainly takes some muscle work.

reverse side

but most of all i enjoy it as an object. the format is an accordion fold, and it’s designed to be displayed opened out, but it can also be read as a normal book. the black covers bely the jewel colours and shimmering text within. as a memorial for a very dear friend it works well for me.

back cover

still awaiting a title…

project sparrow text finishing

having cracked the etch process my next issue was to delineate the text from the background. the etch solution produces a texture which really sparkles under transparent enamel, that i hope will work well with intentional overfiring and incorporation of firescale. but firing clear (flux) enamel over the freshly-stoned raw copper text alters and mutes the colour. to maintain the shine and contrast i intend to use a clear lacquer as the final coat. this will have to be the last step, following completion of enamelling on the reverse side.

lacquered text

project sparrow etch process

with less than 3 weeks to the deadline it feels as though i’ve pretty much cracked the major technical challenge of the project – the text. i need to etch it clearly and deeply enough to accommodate several layers of enamel while leaving the text proud enough to stone back to the bare copper.

the (expensive!) blue transfer paper i started with was temperamental to say the least. once i switched to the (much cheaper and readily available) yellow paper i got much more consistent results. laser printer toner is effectively melted plastic. once that is transferred to the surface of the copper it acts as a resist to the etching solution.

for the depth of relief i need i found the etch began to cut in underneath the toner resist over time and obscure the text. the solution to this is to add another protective/resistant layer. the blue paper does this in a single pass – both toner and a blue plastic layer are transferred. but i had highly inconsistent results.

toner and foil text on bare copper. black electrical tape prevents the edges eroding in the etch.

my refined process was to press the yellow paper at full heat for one minute (pre-warming the  copper to help with registration) then immediately quench in cold water. after about a minute i carefully peeled the paper still under the water to get a virtually flawless transfer. i then re-coat the piece with hot foil – which attaches only to the toner. this double layer gave me a tough enough resist to take an hour of hot etching.

bain-marie with support

suspending the piece in the etch was another challenge. it needs to be face-down in the solution, to allow the ?salts? produced in the reaction to fall away and produce a deep etch. double sided tape and blue foam was a failure – the heat melting even the strongest tape. i finally worked with a stand inside the solution. the roughly cut surface needs to be uppermost otherwise obvious rings appeared where the piece touched the support.

fresh – brown – etch bath

i also found that the etch exhausted much quicker than i expected. the used solution turns from brown to bright green when saturated with copper. i found each batch would last for max 1.5 pieces. i kept the temperature up with a bain-marie made up with virtually boiling water in the large container, which would stay warm enough for one full piece.

finished deep etch – foil has dissolved but black toner remains

project sparrow: workshop notes

testing transfer times from blue film onto pickled copper (not scoured). cheapo iron max temp x 30 sec plus futzing time; straight into cold running water. i’m hitting that point somewhere between cotton and synthetic on my bigger iron in the studio.

now set samples for 30 mins, 45 mins and 60 mins in the heated etch bath, suspended face down. yay blue foam \o/

as for heating, i’m managing pickle and etch in one of these heated, divided lunchboxes.

indicator light doesn’t work but it does heat and what do you expect for a tenner? 😀