I have run into a problem with my steel enamel samples, so of them have had flakes of enamel ‘pinging’ off, and sizeable ones too. After some research I have come to the conclusion that this is probably due to my first coat of enamel being too thick meaning it cannot handle the surface tension and so is cracking off over time. Ways to combat this are to apply several very thin coats building up several layers to create a strong one. another way is to ensure that your steel is really well sandblasted and immaculately clean before enamelling. the other way is to counter enamel the work, however I do not think I want to counter enamel my bowls on the exterior surface, i like the angle grinder sander marks on the surface.
For my large curved test piece I shall sandblast it as well as I can n top of what I have already done and then proceed to enamel and fire as quickly as I can with a very thin coat.
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.
Toady I spent a couple of hours in the afternoon cutting and preparing some more enamel samples for firing on Friday morning. I initially was going to plasma cut my sample pieces off the foot ring that is serving as my sample material but in the end decided to cut them off with an angle grinder. I ended up producing 8 small samples with half the foot ring left for further experiments if needed. One such experiment will be to fire a large curved section in the glass kiln to see how well it works in the kiln firing conditions.
I used an ultra thin cutting disk on the grinder today, I love these disks! They cut so quick and cleanly and you can get very precise with them. They are not chewing through huge amounts of material so there’s less waste and its much quicker. I shall be getting some more of those.
Most of the pieces ended up with lots of different surface markings from different tools, these included wire brush, file marks, grinder sanding pad textures (I love those marks!) and the matte finish of sandblasting.
I had left the lid off my liquid enamel that I made yesterday and it had thickened a bit, the water evaporating in the warm studio over night. The result was a better consistency for smooth application, it needed only a few drops of water to get it just right. I will still play around with this consistency in the future however and see what other results I can get. Whilst preparing my samples in the metal shop I was thinking about how I could produce bowls and forms from sheet steel using the forge and wooden formers….
From clay to community: Theaster Gates on the challenge of blight in Grand Crossings, Chicago at TED2015Posted: March 18, 2015
This is a really intriguing article talking about a persons expansion from their practise as a potter to someone who shapes cities. Starting with super basic materials, at the lowest level of form or materiality and transforming it into something bigger, meaningful and beautiful. It is inspiring the reader to get up and get into changing their community for the better, to go and shape the material that is their local, their community, their urban environment. From clay to cities.
“Beauty is a basic service,” says artist Theaster Gates. He brought the audience to its feet this morning during Creative Ignition at TED, as he told the story of how he went from shaper of clay to shaper of cities.
For fifteen years Gates made pots, “which might seem like a humble vocation,” he says. But in this work, “You very quickly learn how to make great things out of nothing.” When Gates’ father retired from roofing at 80, for example, he gave his son his tar kettle. The younger Gates reimagined this low “nothing material” and elevated it, turning the tar into a series of paintings.
Gates then turned his sights to a different material: the crumbling neighborhood of Grand Crossing on Chicago’s South Side. Gates was disheartened by failing houses there — what he calls…
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I first cut 4 pieces of my gas bottle foot-ring ( 4mm thick)to use for samples. What I was experimenting with and looking for where how well the enamel took to the low-carbon steel, whether there would be any yellow rust stains showing through the enamel (meaning several coats would be needed to get a nice clean background colour to work on) and what my firing would likely be.
I cut these pieces with an angle grinder, but realised afterwards that a plasma cutter would have done the job much quicker, I shall remember this for when I cut my next test pieces tomorrow.
Then I proceeded sand them with the angle grinder sanding wheel and then sand blasted them to ensure they were super clean providing a good texture for the enamel to ‘adhere’ to also.
The enamel I am using on my steel is specifically for steel (perhaps more steel sheet but it seems to work well) once there is a layer down on the metal fired to satisfaction I should then be able to enamel on-top of that coat using regular copper, silver and gold enamels. The enamel I bought for this is a super fine liquid enamel from W.G. Ball – a British enamel supplier I think. It is in powder form so you mix it with water yourself. They (on their website) recommend 8 parts enamel powder to 3 parts boiling water. They also recommend firing at 800C for 3 mins (their tests on 10 x 10cm, 1.6mm gauge steel sheet).
I started with a 3 minute firing and got a poor result so did subsequent, 4, 5 and then 6 minute firings and saw much improvement with the enamel fluxing properly and smoothing out. Roughly 6 mins was needed to get a satisfactory result , tomorrow I aim to get this down to a t and find my best firing temps. It looks pretty good, I need to find a smooth application technique to get nice even coverings, they are all a little patchy unfortunately. I will design a set up that will be efficient and tidy and let me get the results I want before firing.
I have plans for future enamel experiments. I shall do a 10 minute firing to test the extremes of the metal and enamel and a large curved piece in the glass kiln to see what happens in the temp fall period – Im scared the enamel will burn out in the large glass kiln as I cant open it at temperature, it has to shut down and I have to wait until it is cold before cracking open. I will also cut some smaller sample pieces for faster experiments (so they can be pour and dip covered ideally) when it comes to trying out possible enamel design ideas.
There shall be a follow post about the progress all this takes.
This is an exciting idea something I would like to read more on.
This is my first medal prototype and first small CNC project…