Delft clay casting, pt1: tools issues, copper issues, and a lot of issues in general. And shibuichi.

If you're following me on google+, you may know that I recently ordered supplies for casting. I have a lot of scrap copper laying around, and I wouldn't be able to make anything out of it, so I've decided to try my hand at casting. This way I could still use that copper, and it wouldn't be wasted.
 So, I've got my waxes, crucible, tongs, and of course the delft clay, and got to casting. And found out that melting copper is a pain. It either wouldn't melt at all, or wouldn't stay liquid long enough for me to pour it into the mould. It was frustrating, to say the least.

Tools!

I've spent 1.5 day trying to melt the copper. Then, at the second day, I manged to do this, and it aaalmost stayed liquid long enough to pour it, but it hardened as it was flowing toward the edge of the crucible. I deemed that partial success, and was eager to try again, and that's when I noticed this:

 

Poor torch :(

I did manage to melt the copper, but the plastic casing of my torch... not exactly melted, but, well, did what you can see in the pictures. I got pretty scared it wouldn't work, or that I wouldn't be able to change burners, but after it cooled I found out that I can remove the burner and attach another, the torch works, and the only damaged part is the upper right hand side of the casing closest to the nozzle.
Thankfully, the damaged part isn't anything vital for the torch operation, and the damage is superficial, and limited only to this side.

Feels ;(

But it's pretty clear that one won't melt copper without taking damage. So I had buy another. At first I wanted to order something via internet, but then anything I liked was expensive, and I would have to wait another several days before I would be able to continue my casting experiments, so in the end I went shopping, remembering that the shop I got this torch stocked also a bigger one, without any plastic parts near the nozzle.

It's huge and quite scary

This one makes the biggest flame I ever handled, and unfortunately doesn't have automatic ignition. By now, I got the hang of firing it up, but the first time was scaaryy. Sorry for the crappy pictures, by the way.
Huge flame or not, I still had problems melting the copper. I'm not sure what I'm doing wrong, but I can get it to a semi-liquid state, and then... it suddenly cools and solidifies. I don't know if I direct the flame wrong way or what, but that's what happens.
So I got rather discouraged and angry. I also remembered I had a little bit of scrap silver, and decided to see if I can melt that. And if I can pour it into the mould. It went much easier, though I had to try 3 or 4 time before I managed to get it into the mould without the metal solidifying half-way through.
However, I had only 2.8g, not enough to cast anything. But at least I got to practice pouring the metal. It's not that easy.
But I still wanted to melt that scrap copper. And today I read about Japanese copper and silver alloy, called shibuichi. It comes in different ratios: one is basically sterling silver, but there are other kinds with bigger amount of copper. It can be 90%copper 10% silver, or 95%copper 5%silver, or 60%silver 40% copper, and so on. There are also mixes with tiny percentage of gold (like 1%). what's more, it melts in lower temperature than copper and pure silver. I decided to make 70% copper 30%silver mix.
I thought I would have to melt copper entirely before adding silver. But, typically for Murphy's Law, when I needed molten copper, it just wouldn't melt. I got angry, and tossed the silver in when the copper wouldn't get to even the half-liquid state. The silver melted right away. And, surprise, surprise... suddenly I had crucible of fully liquid metal. It took seconds for copper to melt as well once the silver was introduced.
I managed to get it into the mould as well, and quite easily at that.

Crucible with a little bit of metal solidified near the edge. The red stuff is borax. Not sure why it's red.

I don't have enough of that alloy to cast any of the models I have, not even enough for one thin ring band, but I'm going to buy a bit of silver casting grain, and make some more.
It has a lovely colour, kind of silverish-brown with a light pink undertones. It reminds me mostly of pink gold, though it's lighter in colour.
I have only one, bad picture, but here it is:

Partial success at casting

The yellow is patina, it can be easily removed with sand paper. It's not anywhere near perfect, but I'm happy I can melt it, and keep it liquid long enough to obtain the cast. I'm not sure why there are those tiny dimples in the casting. I'm going to rummage through the internets and try to find out.
Ufff... so that was the first week of delft casting experiments. I'm definitely more encourage to keep learning this now that I actually have metal that I can melt. The details wouldn't be bad if it wasn't for those bubbles, holes, or whatever these are.
I hope the next week will be more better!
Till the next time,
Kasia.
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