Experimenting with "White Bronze" clay

The last couple of years have seen an influx in new metal clays, including bronze, copper and steel made by different companies.  The latest in these is a new "white bronze" that Hadar Jacobson is making.  She supplies her metal clays in powder form and so you mix them yourself by adding just water.

I liked the look of her new white bronze clay so thought I'd give it a try.

As I often find with Hadar's clays, when I mix them according to her directions, they seem to slump when making thicker sculptural pieces and this is what happened with my first try with white bronze.  As it dries, it just doesn't hold it's form and flattens out.  So I decided to cut that piece into three and use them for some test firings to check what temperature is correct for my kiln.

Here's what one of the cut up pieces came out like after firing - finished only roughly - dark silvery grey color:

I then made up a new batch and added less water than Hadar suggests so that it wasn't quite collecting in the bowl.  Then I rolled this, adding the tiniest more bit of water,  and it came together and didn't slump as it dried.  It is on the verge of cracking but doesn't quite - so it is not the satiny feel that Hadar uses for her pieces and shows in her videos.  Anyhow - this drier form seems to keep sculptural pieces in their shape.

I made two of the drier batches and have just fired those.  The kiln settings seem fine - but both these pieces came out quite yellowy.  Here's one of my little birds -  not as yellow as traditional bronze but still a lot yellower than the test piece.  (I tried firing niobium wire embedded in him but it seemed wobbly which is what the little blob on his head is!):

So the final color of these last two pieces - each made with a different batch of drier clay - is quite different from the test piece and also from Hadar's work on her blog.  I can't imagine that just adding less water would take away the "white" coloring so I wonder what it was?  I'll see what Hadar has to say.

Here are three pieces for comparison.  The bird on the left is silver, the test piece in white bronze is in the middle and the yellowy white bronze bird is on the right.

Maybe it's just me and bronze! The prometheus bronze came out pink and now the white bronze comes out yellow????  Anyone else been trying this out?  what did you find?