The " solders " used for red gold contain 1 part of copper and 5 of gold; for light gold, 1 part of copper, I of silver and 4 of gold.
It also explains why aluminium is so difficult to join with lowtemperature solders, for these mostly contain a large proportion of lead.
Certainly if conventional lead-containing solders have been used, it may be prudent to repair using the same materials.
This is increasingly the case, as lead-free soldering is beginning to be introduced to the industry with its accompanying higher melting point solders.
The solders of the Roman Empire served for twenty years.
