More Steel Enamel SamplesPosted: March 20, 2015
Today I set the temperature to 825C so that when I open the door the drop in temp will not fall too low below the firing temperature. Here I am hoping for a better firing and enamel surface quality. Some of the pieces have a second enamel coat applied, with the aim of being a few layers thick so that I can determine how many I layers I need for my base layers.
Some of the samples have a few yellow rust stains which rose through the unfired enamel to make a few spotted yellow stains – I will see how these turn out with firing. If these stains are very visible I may need a couple more coats. I think several coats may be needed before I can do my final mixed coat with the jewellery enamel in the bowl.
All sample pieces come from the foot ring of the bowl gas bottles. The low-carbon steel is 4mm thick. All test pieces are approx’ 4×7 cm.
- First Firing – 5 Mins at 826C, 2 small sample pieces.
- Second Firing – 6 mins at 826C, 2 small sample pieces with rust spots. Temperature fell to 750C when I opened the door so I waited until it was back to firing temperature(took 5 mins to return to temperature) then started the timer. – maybe these could have done with an extra 30 seconds to get a bit more smooth but that could easily be down to the application of the enamel. The yellow rust spots disappeared from the pieces but Im not sure this would be the case for large piece of work like my steel bowls.
- Third Firing – 7 mins at 826C, 2 small sample pieces, one with sgraffito river design. Opening door dropped temp to 750C, I let the temp rise to 800 before setting timer. Took about 5 minutes to reach temperature. These burnt out pretty badly, mst of the enamel was gone from the surface, the enamel on the curves survived a little better.
- Fourth Firing – 7 mins at 826C, 2 larger peices, second layer firing, Surface and Curve. This was timed straight from pieces being put in kiln, the door is only open for 3 seconds but temp still fell to 750, it is my hope that the 7 min firing wont burn out like the last one as the rise to temp (826C) is included in the timing, hoping for smooth perfectly fluxed second coats. – These turned out pretty well, a tad long firing I think, the first signs of burning out, one of the pieces is beautiful the other is a little patchy but pretty good, perhaps a third coat at 800C for 6mins would be perfect.
- Fifth Firing – 8 mins at 826C, 1 small sample piece, first layer, testing extremes of prolonged firing.– Didnt burn out too badly, a nice effect obtained here.
- Sixth Firing – 6 mins 30 seconds at 826C, 1 small sample piece, first layer, testing prolonged firing times. Seemed to burn out way to quickly, maybe applied coat was too thin… I think I need to do more firings at 5mins 800C.
I think next time I shall lower the temp back down to 800 again and just wait for the temp to rise before timing.