koftgari preservation question

Philip · 17th September 2017, 11:54 PM

Marius you have posted some very sound advice about preservation. The trouble with koftgari is that corrosion that starts in the exposed iron around the gold decorative motifs can eventually eat underneath the precious metal (which after all is a thin foil on top of a roughened surface, a mechanical bond without any chemical adhesion or sealing whatsoever). This corrosion going underneath is what causes exfoliation.

Using waxes and other things is of little use in areas where the corrosion is still working, and not removed. The rust will keep going, over long enough time, under the wax. I make it a point to remove as much of the visible rust BETWEEN the decorative elements, using fine dentistry tools and micro diamond rifflers, without disturbing the overlay or leaving patches of bright over-cleaned metal. It can be a slow process, not very exciting work, but at least you know that your item will survived that much longer with its decoration intact, after you do the final cleanup and apply your wax coat.

17th September 2017, 11:54 PM	#5
Philip Member Join Date: Dec 2004 Location: California Posts: 1,036	Marius you have posted some very sound advice about preservation. The trouble with koftgari is that corrosion that starts in the exposed iron around the gold decorative motifs can eventually eat underneath the precious metal (which after all is a thin foil on top of a roughened surface, a mechanical bond without any chemical adhesion or sealing whatsoever). This corrosion going underneath is what causes exfoliation. Using waxes and other things is of little use in areas where the corrosion is still working, and not removed. The rust will keep going, over long enough time, under the wax. I make it a point to remove as much of the visible rust BETWEEN the decorative elements, using fine dentistry tools and micro diamond rifflers, without disturbing the overlay or leaving patches of bright over-cleaned metal. It can be a slow process, not very exciting work, but at least you know that your item will survived that much longer with its decoration intact, after you do the final cleanup and apply your wax coat.