I have been having problems also with soldering a 14k yellow gold
jump ring to an 18k bezel using 18k yellow paste solder. When I bend
it a little the ring stays on but then comes off later. The surfaces
have been filed clean and then fluxed on repeated tries. A friend
has suggested that I use more solder but now I have been wondering if
the red gold isn’t the problem?
Peter, I have read your post a few times to hopefully understand your
problem. What I am reading is that you are using a flux and adding
it to the place where you will spot solder. When using paste solder
in general, there is no need for flux. The paste that I manufacture
at Unique Solutions, Inc., has flux included in the non-drying
formula. There is no need to add flux and in many cases it will
fight the flux provided in the paste. You are correct in making the
places to be joined filed and cleaned. With paste solder, you do
not need to be that fussy about getting it super filed. Paste is a
lot more forgiving than
sheet and flux. The other thing is that you must get each piece you
want to join together to the proper temperature to make the paste
solder flows properly. If you do not get both surfaces to the proper
temperature, then you will have a “cold” connection or a place where
the solder is just holding on, but has not really flowed and making a
good and soldered join. This also seems from your description, to be
what is happening. If both parts have not reached temperature, they
will separate. You do not have to heat the whole piece as with silver,
but you need to get both surfaces to be joined at the proper tempera
ture so the solder will flow into the place you want to have joined.
One hint. If you do not want to have the solder flow anyplace other
than where you want it, put an anti flux around the join making sure
not to put the anti flux in the place you want the solder to flow and
join the pieces together. To many, paste solder is a new experience.
Many have been taught with the flux and sheet and just assume it
goes the same way using the paste. No one has bothered to tell them
that you do not add flux! A very big plus with paste solder is that
you do not have to spent all that time to dry the flux, making sure
the chips or pallions do not jump of the place to joined. You just
in effect, point and shoot, placing the solder exactly where you want
it. On surfaces that are not flat, it is much, much easier to get
the paste to hold to two curved surfaces to be joined, rather than
balancing the chips and hoping for the best. The paste is just that,
a paste and forms to uneven surfaces very easily. Of course, if you
are soldering a ring in the air then there is a challenge. All that
comes with experience just like anything else, but paste makes it so
much easier. Beth Katz
Peter, You should try using a 14K easy solder or at least a 14K plumb
solder. I would watch the melting and flow temp of 18K solder it is
likely higher than your 14K piece. Good Luck, Rich.