Showing posts with label melting. Show all posts
Showing posts with label melting. Show all posts

Friday, 15 February 2013

Ceramics: slabwork.

First, I made 6 squares of clay the same size, and used my collected objects to imprint patterns onto the surface. I tried to make each square different, as I wanted all the sides of my cube to be a surprise, which you had to ppick up and turn around to find all the patterns. I mitred all the sides at a 45 degree angle, so the joins were not visible on the outside.



I used slip to join the edges and make them look neat, and also put reinforcements on the inside of the cube to strengthen it.
I next rolled out some more clay and made cylinders, to put together to make a repeating pattern similar to how I made the triangle.
I put marbles into the bottom of the cylinders, to hopefully melt and create a decorative abstract piece in the bottom of each cylinder. I have used marbles because I have lots of marbles and would like to make something new out of them.


Thursday, 27 December 2012

Metalwork: Vessels.

In our skills building phase, we learnt two different ways of making metal vessels, both hand raising and spinning. The first bowl I made was hand raised using a hammer and a stake. I found this quite difficult at first, because the disc of metal was still quite flat and it was hard to get the sides to come inwards without creating pleats or changing the shape of the bowl. I had to anneal the bowl several times while I was hammering it, because working with the metal makes it harder and more difficult to shape. 
 After looking at pottery shards, I started to think about how each of the shards had come from something, a pot or a plate, and I wanted to bring this theme into my metalwork as well as my ceramics. Using a piercing saw, I cut out an angular 'shard' shape from my copper bowl, and flattened it. I could then accurately copy the shape on to a piece of brass, which I reticulated to give it an interesting pattern and texture.
 I sewed this into the gap using wire, drilling small holes in both pieces to thread it though. I think this looks as if the bowl has been reconstructed from the shard, like an archaeologist would do.
I like the interesting idea of having a shard of metal. metal doesnt naturally shatter or crack, because it is malleable it would dent rather than break.

The next bowl I made was on the lathe, which gave it a very smooth surface, and a very regular shape because it was formed onto a block. I was pleased with how the bowl turned out, but I thought it was quite plain, and although I enjoyed the process, the outcome didn't really fit with my theme.
 For this reason, I decided to follow the same idea as my first bowl, but with a process more suited to the material. I first thought of hammering or dropping the bowl, and then trying to mend the bowl in an interesting way, but after some thought (and some encouragement from my metalwork tutor) I let one of my classmates take the bowl, with the instruction 'damage it, but don't destroy it' This was so I couldn't decide how to fix the bowl before I damaged it, as I would not know what the damage would be.
 A few minutes later, my bowl was returned, looking far less shiny and new than it had previously. He had used a micro welder to melt through the sides of the bowl, so there were now gaps in them, and also blobs of metal on the inside.
I did some quick sketches of ideas to decide how to mend the bowl, concentrating on decoration, not function.
 I then decided to hammer the middle part, in between the melted slits, to broaden it so the gaps were not as big. This also flattened the blobs of metal on the inside, some of them even fell off completely.
 I then did some more sketches of repairs I could do to make sure the pieces do not come apart.
I liked the idea of having round or oval bridges across the gaps, riveted in place on both sides, because this would be both decorative and unusual. I cut the ovals out of brass with a piercing saw, reticulated them, and drilled holes in both sides. I then used copper rivets to attach them to the bowl, doing one side of each oval before drilling the second hole in the bowl, so that they definitely lined up when I put the second rivets in.
 The rivets are quite noticeable on top of the brass, and I like the detail they create, which wouldn't be there had I soldered the pieces on. On the inside of the bowl, only a tiny amount of brass is visible through the gaps, and instead of the rivets contrasting the colour of the bowl, they add to the texture of where the copper was melted.
 I used powdered pumice stone and some liquid soap to give the surface a satin finish. I used a toothbrush to apply it, and followed the shape of the bowl where I could, so the brush marks went around the bowl and there were no harsh angular lines.

Saturday, 15 December 2012

Metalwork: Casting.

 One part mold:
First, I filled a cardboard ring with casting sand, and pressed it down with a mallet. I pressed in my small objects, which I chose to relate to archaeology, things people have left behind.

I melted some pewter in a small crucible, and poured it on to my mold. I quite like the outcome of this, but there wasnt enough pewter to cover all of the mold, because so much of it does not go into the imprints of the items, but stays in the gaps on the surface of the sand.


I think this gave good detail, but only half of the object comes out, because if it was pushed more than halfway into the sand, it couldn't be taken out of the sand without damaging the mold.

Two part mold:
Similar to the one part mold, the first step was to fill a ring with sand and press the object in half way. Then, to make the other half, I covered the visible sand with talc, and put another metal ring on top, making sure the notches on the edge lined up. I then filled the second ring with sand, then separated the two (the talc stopped the two halves sticking together). I took the pick axe out, and drilled a hole through the sand so there was a channel for the metal to go through to get into the mold when the two halves were put back together.


 I poured the pewter into the mold, then separated the two parts. I dug the sand out and cooled the metal in water. I then cut of the sprue where the metal went in (and put it back into the crucible to be melted down again, Then used files and wet and dry paper to smooth the surface of the metal axe.

I used the same technique to make a shovel, and found this worked well because the two part mold allowed there to be the hole in the handle.
I really enjoyed the casting process, so decided to try with brass. Brass has a higher melting point than pewter, so it took a long time to heat it to a liquid. Instead of filing it smooth, this time I left the texture from the sand, so instead of being a small shovel, it is easy to tell it is a cast shovel.