Sunday, January 16, 2011

Clio & Fuming

Remember I did Double Helix Clio over Cirrus a few days ago - and it fumed the Cirrus and made it look yellowish.

I tried Clio over the Lauscha Milky Way, and also got a yellowish tint, for the same reason.

And here's the two together, just for comparison. The Cirrus/Clio combo is the top mandrel, and the Milky Way/Clio combo is the bottom mandrel.

I think perhaps I should make sure we're all clear what "fumed" means.

Usually, fuming is achieved by taking either pure silver or pure gold metal, and holding it (usually by sticking it to a glass rod, like boro or quartz rod) - holding it in a reduction flame, below the bead or item that you wish to fume. So the metal is held in the flame closer to the torch, and the item to be fumed is held out at the end of the flame.

The metal heats and boils and evaporates, and is carried away by the rising flame - but some of it is deposited on the bead/item that is at the tip of the flame, as it rises and goes past it. This deposits a very thin layer of the metal on the bead/item. This creates either a shiny layer of the metal, very thin, or a reaction, i.e. when silver reacts with a glass to create a new colour.

Generally - that is what is meant by "fuming."

However, with the new category of silver saturated glasses, such as the Double Helix, TAG, and Precision 104 glasses - the silver content is so high that fundamentally, the same thing happens. The silver in the glass is evaporated off and affects the glass around it, creating the same kind of reactions.

One of the classic silver reactions is silver with clear and white to give a yellowish colour. (This is why it is hard to keep encased silver looking silver - it looks gold in places - because of the silver reacting with the glass.)

So that is why it makes sense that the base beads turn yellowish in the presence of a high silver content glass.

That's what we mean by fuming.

1 comment:

  1. Gail Davis Bryant3:22 PM

    Helpful ino, DJ; I've never heard such a detailed explanation. Thanks.