In an effort to insure that nothing was lost or confused in translation, the formulas given here were tested on a wide range of alloys. These pages show some of our results.
It is important to understand that many variables will affect patina results. Our tests were made on smooth, rolled metal. Textures will change the color, and cast metal has a different structure that can also influence color. These samples include no solder, and because solder is a different alloy, it will react to the solutions differently. Changes in temperature, length of exposure, climate, and strength of the chemicals wilt all influence colors.
Experiments like this are the best way to develop an understanding of the solutions that will prepare you to apply the patinas on your finished work. We recommend making tests on small pieces like this before you mix up large quantities of patina solutions or devote a lot of time coloring a large piece.
Testing Japanese Patina Solutions
Niage on Copper
The metal was cleaned with pumice, rinsed in water, and allowed to sit in grated daikon radish. The niage solution was heated to just below boiling, and the work was immersed for about 30 minutes.
Niage on Red Brass
This sample was handled exactly as described above; cleaned, rinsed, and immersed in simmering solution for a half hour.
Niage on Shaku-do
This piece was given the same treatment as the others on this page: clean, rinse, warm in solution for about a half hour.
Niage on Shihu-ichi
The metal was cleaned with pumice, rinsed, and laid into daikon pulp. It was then suspended in simmering niage solution for about 30 minutes.
Niage on Yellow Brass
This piece was handled the same as the one above, also immersed in hot niage for about a half hour.
Ohaguro on Red Brass
The upper portion was given a foundation of su-tanpan, and the lower half has a niage layer. The metal was warmed with a torch and the ohahuro solution was brushed on, drying as it touched.
Ohaguro on Shaku-do
All the samples on this page haw a base of su-tanpan patina; die lower half has niage. In this case, the metal was heated, then ohaguro was brushed on so it dried on contact. Five layers were applied.
Ohaguro on Shihu-ichi
As above, the metal was heated to the point where the ohaguro solution spritzed and dried on contact. Again, five layers were applied.
Ryusando on Shaku-do
In this case no heat was used. The ryusando solution was brushed on at room temperature and allowed to dry naturally. Five layers were applied. The top half has a su-tan-pan foundation and the lower half has a niage foundation.
Su-tanpan on Copper
The samples on these two pages were handled in the same manner. After cleaning with pumice, the tiles were covered with daikon mash, then warmed in the relevant solutions for about a half hour.
Su-tanpan on Red Brass
As above. The subtle color has the appearance of leather.
Su-tanpan on Shaku-do
This was the darkest color of the combinations of recipe and alloy that we tested.
Su-tanpan on Sterling
This subtle color has elements of red and amber.
Su-tanpan on Yellow Brass
This color is a rich brown, similar, perhaps, to the color of an acorn.
Kin-furubi on Sterling
This patina is gray infused with deep reds.
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