Category: workshops

enamelling #2

another morning in the workshop and a whole batch of samples.

it looks as though my problems with the mexican red weren’t firescale related after all. the top set of samples were counter enamelled first and firescale not removed from front sides. everything was fired at 805• with a timer set for 3 minutes (except when i forgot!). all samples were scrubbed with a scourer under running water before enamelling.

counter-enamelled pieces kept their shape.

clockwise from top left:

  • firescale with transparent (flux) enamel.
  • royal blue opaque enamel with turquoise beads. enamel and beads applied together in a single layer, with additional enamel over the beads. the beads have partially melted but remain raised above the surface.
  • royal blue enamel overlaid with sterling silver wires. the wires released from the surface after firing
  • royal blue enamel, single layer.
  • turquoise opaque enamel with turquoise glass beads. overfired – i forgot to set the timer. the beads have completely melted into the enamel, which has a badly pitted surface.

it’s noticeable that the counter-enamelled pieces have kept their shape while those without enamel on the back flattened out due to contraction of the enamel surface.

pieces only enamelled on one side only flattened out during firing.

clockwise from top left:

  • turquoise opaque enamel sifted over copper mesh resist.
  • layer #1 turquoise transparent enamel. layer #2 rollered copper mesh and turquoise enamel. the wire has fused into the enamel. this piece was bent after firing and the enamel has cracked.
  • layer #1 flux. layer #2 turquoise transparent enamel.
  • turquoise enamel single payer. this piece is more green/blue than shows in the picture.
  • layer #1 green opaque enamel. the powder was lumpy and wouldn’t sift so i pushed it through with a spatula. the result was very bumpy and uneven. layer #2 flux. layer #3 turquoise transparent enamel. this piece might be interesting if ground flat to remove the raised areas.

i noticed that fire scaled pieces when handled warm would crack and flake off, leaving the shiny copper below. pieces left until cold were more evenly covered. above pieces left-right: even coating left til cold, covered with layer of flux, handled and flaked off.

counter enamels

we have 2 different pots of counter-enamel. the smaller pot is green and the larger one is more of a bronze colour. concentrating on sifting extra powder over the edges helped to achieve a much more even finish. 2 minutes was adequate firing time for the backing enamel.


glass workshops: enamelling

my first attempt at enamelling has taught me plenty of lessons…

backing enamel, applied first.

lesson #1: enamel pulls away from the edges and towards the centre during hot firings (iirc the kiln was set to 805•c). extra enamel should be sifted onto the outer edges.

lesson #2: if the trivet touches the enamel it will show. a wider trivet that only supports the edges would have been a better choice.

lesson #3: overfiring. the back isn’t smooth, but pitted, possibly the result of 3 x 3 minute firings.

front: mexican red, two layers, each fired for approx. 3 minutes.

lesson #4: cleaning is important! i fired the back first, leaving the uncoated front flaky (firescale). i gave it a rub with a paper towel but not enough to remove the scale or the oils from my fingers (presumably around the edges). a second layer/firing did nothing to improve the finish. a scouring pad under running water or commercial cleaner could have prevented the discolouration. (wire wool is not recommended due to the risk of contamination/pitting)

lesson #5: contamination is obvious! i used a sieve that had previously been used with white enamel. the white spots are the result.

lesson #6: inaccurately placed holes are also obvious.

lesson #7: serendipity is fun. i made a stellar nursery 😀

orion nebula

references: linda darty, the art of enamelling, 2004.