What a beautiful piece!We all are dying to know how you got that coloration. Looks as if it's titanium. Heated stainless? A beautiful detail. Janet R.

ferrous, as opposed to nonferrous, does need to be foldformed hot. :)

I posted this at the BLOG post before I saw the BIG IMAGE :)

beautiful colors. Thanks for posting this, Giusseppe.
I'm guessing that you don't put any protective coating over the temper colors. How long do they last in an exterior environment? Do they "tone down" a lil with time?

bill
"lost in the details"
:)

very long lasting - see blog comment

the key to all these colours is perfect cleanliness up to the moment of heating .... I often heat with the surface wet with well water on the surface but I have also used urine or dilute nitric .... the latter can create interesting drip and run lines.

The other key is electropolishing, my daughter did about 20 samples for her science fair and we concluded that the best range and durability came from electropolished and acid washed in a closed oven. If the piece is small then the best even colours come from an electric kiln or glass blowers annealing oven.

on larger pieces we use a technique where gold is achieved initially and other colours dragged in after .... this gives a more vibrant depth .... sometimes on large surfaces I will heat and cool several times to increase depth.

as you know, silver stainless is naturally covered in a protective layer of chromium oxide ... the colours are simply a visible version of that oxide layer which is very tough.

there are more exotic metals in 316 which yeild a greater range of shades.

as for the folding ... most is done cold for more control ....stainless can be annealed by fast cooling but I find that the surface retaines less dirty oxide if we slow cool.

`Hi there! It`s nice for new starters, to learn little things that are rutine for experienced guys. What do you think could happen if a sculpture has copper and stainless in contact,and exposed to weather? I`m worry about stainless staying so,don`t mind green Cu sulphates,and oxides. Thanks for your help. nelson

good question nelson

I guess that calls for an excursion to a piece were I brazed copper to stainless, polished the stainless and then patinaed the copper about 6 years ago.
It has been sitting outside for the last 4.

it was mainly a materials study piece.
hmmmmm where is that camera . . . .

hmmmmm stone base is frozen down to a stone table; it will have to wait til I can get it out of the corner.
So, prey for warm, and I'll catch it.

one nice thing about copper and stainless as a pair is that their coefficients of expansion are almost the same.

(much like concrete and mild steel)

Gene Olson
Sculptor
Elk River, MN

much of my work uses bronzes, copper and stainless joined (often with TIG) no problems from a decorative viewpoint but such mixes would not be good if there were structural stresses.

Gene Olson Sculptor Elk River, MN

Darn it! Gene could you please send a little of that cool weather, over here it`s always 30-35 Celsius during the day... I know what you`d say! Anyhow thanks por pick and comment. I can`t notice rust on stainless, and my concern was not structural as it is electrochemical. Thanks. Nelson.