Peter , and all . This may be a chance for me to learn more . Many
years ago I read that the “old” way to make solder was to use the
same alloy that you are fabricating in and alloy down , two to four
karats to make solder . I worked briefly with a jeweler who did just
this , learned from his father , from South America.
“My” rose gold recipie is as follows for 18k ; 76gr.fine gold [I
always over karat] 22.5 gr. pure copper and 1.5 gr fine silver . I
used to alloy just gold and copper but the small addition of silver
seems to reduce oxidation and improve working characterstics with
negligible color change.
When alloying 14k [ 59 gr. fine gold ] I bump silver into the 3-4%
range , Alloying only a dwt at a time makes for a rather more
variable mixture than the 100gr I usually make, so I try to be
extra careful with my measurements , and use our "legal for trade"
diamond balance to weigh the metals and use a nice clean crucible
too … The first time I tried this the “lower” k solders seemed to
have a HIGHER melting point so I bumped up the silver even more
,and added some commercial alloy containing zinc , but then you
start to lose the color . As I write this I think I understand why
there is no good Red gold solder , copper melts at a higher temp
than gold as you search for an alloy that will both melt and have
color you can have one ,or the other . ?? I’m sorry this is not so
formulaic but was done , some 10-15 yr’s ago and I’m still using the
same pices of solder today .
Like I said in the first post it is NOT a “good” solder , as
solders go , the 12k is VERY hard and will leave some “artifacts” as
the paillion melts but it will allow “seamless” soldering …
now the surface of the seam may need to be worked slightly to get
that seamless look as you may get a little “orange peel” from being
so close to the melting temp, I am a great fan of the “rotary
hammer” or “porosity killer” - margin rollers don;'t last as long as
the solid metal ones do.
If/when I would try to make more solder today I might try a Higher
karat alloy …as a solder … I know there are participants here
who are really knowlegable in metalurgy/alloys . Is there truley no
such thing as a good red gold solder ?
Also , I’ve seen a “redder” gold in some jewelry from Italy than
any I’ve been able to make myself , any comments?