Saturday, April 01, 2006
Inside of Old Sheffield Plate, is the old pitch, the metal rod, and alot of lead solder.
A steel plate covers the bottom, this is removed by heating carefully and removing lead solder. It usually pops out when the heat is just hot enough for the pitch to almost explode and the lead melts. This is a dirty job, so you want strong venting.
I am assuming when these were made the Smiths did not know that the contact of Steel and Copper are a corrosive combination. All of the old candelabra the I have taken apart are usually based with steel, some are wood. But all Old Sheffield Plate were with steel.
When I repack, I use copper to make the base not steel. These were particularly corroded. The base steel was corroded through and the copper in the thinest parts were corroded through. As you can see I had to make a mold of what remained in the rim around base part and cast new parts. These silver pieces were fabricated to make a new round circle and all the parts put back together.
Pitch that was used for packing sometimes is more explosive than others. A full mask is used for unpacking and clothes you do not care about. This includes knife handles as well.
For those of you who do not know what OSP is, it is a layering of copper and silver that was fused together in ovens and then rolled out very thin to make the sheet metal that was used to make, all of the old antique silver called Old Sheffield Plate. It has a thicker amount of silver on the surface of the copper than a piece that has been plated.
It is a great illusion.
Posted by Smithing at 7:40 AM