The Gates of Paradise are truly fascinating!
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| Gates of Paradise by HarshLight |
As incredible as these doors are there isn't very much written about how Ghiberti actually made them. Most of the articles I found just focus on describing them and discussing the restoration work that has recently been performed on them. I was thankful to find one article at artic.edu that did a great job of describing the actual process Ghiberti went through.
Here is what it says,
"During the Renaissance, bronze was far more costly than marble, and it
posed significant technical difficulties in an age before industrial casting.
Ghiberti created the Gates of Paradise using a technique known as lost-wax
casting. After making drawings and sketch models in clay or wax, he prepared
full-scale, detailed wax representations of every component of the reliefs.
(Some scientists and scholars believe that he modeled his reliefs directly in
wax; others propose that he made an initial model in another material and then
made an indirect wax cast.) When Ghiberti and his assistants finished a model,
they added wax rods in branching patterns to its back. The entire relief was
then covered in a fire-resistant material like clay and heated until the wax melted
out, leaving a hollow mold. The spaces that had been occupied by the rods
served as sprues (channels) through which bronze reached the surface of the
relief. The sprues were cut away from the reliefs after casting, but their
remains are still visible on the back of each panel.
Ghiberti’s work was only half finished when he took the bronzes out of
their molds. He still needed to complete the time-consuming and tedious work of
chasing—that is, hammering, carving, incising, and polishing the reliefs. Utilizing
his training as a goldsmith, he directed his numerous assistants in cleaning
and enhancing details on the surface of the metal.
Ghiberti used a bronze alloy that was somewhat more difficult to cast
than other bronzes of the period but was also very receptive to gilding. He
mixed gold dust with mercury and painted the mixture across the front surface
of each relief. Some of his brushstrokes are still visible, but, for the most
part, he succeeded in creating a smooth, luminous surface that suggests air and
atmosphere. To make the gold adhere to the bronze, Ghiberti heated each relief
to burn off the mercury, leaving only the gold in place. This was a toxic and
dangerous process that is no longer used."
During Week
14 we will be creating a Florentine Relief in imitation of Ghiberti's Gates
of Paradise. For the examples I created I
elected not to use the thick tooling foil that came with the kit I ordered for our community.
Instead, I used these squares and some regular
aluminum foil.
This is the regular piece of aluminum foil that I tested. It is slightly thicker than the gold foil pictured below. I rubbed the tempera paint off this one with a damp paper towel and found that is was very easy to do. I highly recommend this removal method.
This foil is very thin and was torn easily when I tested the steel wool on it. I don't imagine this would be the case with the heavy gauge tooling foil. After ripping the foil I switched to the damp paper towel and it removed the paint very easily.
For more about this project check out the video below!
