The BEST way? scrap it. Chains like this often are not worth
repairing. If it actually is made without soldered links, rather
than being a faulty chain where some joints didn’t solder, then
it was originally designed so that the spring tension on the work
hardened links would hold it together. Not a great chain in the
first place. Once these wear, the “springs” become thin at the
contact points between links, and the chain links bend,
seperating the links. Before attempting any repair, you should
carefully examine this chain for several things. One, is it
simply one link, that broke as a fluke, and the rest of the chain
is OK? Two, is the thing actually gold? test it. Chains made
without soldered links are very often gold filled or gold plated.
These are often not worth your time to repair.
One exception is those chains that are not actually box chains,
since the “arms” of each link have little bulges/tabs on the end,
so that when the links are assembled together, they truly
interlock, providing strength unless the chain is really
deformed. This type is repaired by removing damaged links that
have cracked, and either coaxing the next two good links back
together, or simply soldering them. But I don’t think this is
what you have, is it?
IF the chain appears to be otherwise in fine condition, rather
than being worn, one possible plan is to remove the damaged
links, and join the broken ends with a very tiny jump ring,
rather than trying to reconnect the links themselves. The jump
ring may allow you to solder it shut without heating the chain
links themselves, or you can leave it unsoldered if the wire is
not annealed and is heavy enough. Use your best judgement here.
It’s an ugly looking repair, but may be the best bet for some of
these chains.
For soldering it, which might look the best, you can use the
easiest solder you can find, even a low melting solder like
"TIX", to anchor the broken link shut. A gold solder looks better
and is stronger, but gets hot enough that the link becomes
annealed. If the links are large enough or loose enough that
you can do this so that only the soldered link is heated, this
may work. but if the adjacent links also become annealed, as
they usually do (they don’t have to get anywhere near the actual
soldering temp to loose their temper), then while the solder
joint is strong, the link next to the soldered one is now soft
and weak enough that it may not even make it out the door with
the customer before itself letting go. With “TIX”, or
"Stay-brite" or similar tin/silver or lead solder, at least
you’re not annealing the adjacent links, but then the repair
looks like some butcher with no self respect did it.
And even so, when one link in any chain breaks, its often
indicative that others are nearly ready to do the same, but just
didn’t quite fail before the one that did break. So with these
chains that are not well made, even when they look good,
soldering one link can be an exercise in frustration for both
you and the customer. You fix one link, and then the customer
feels that now, since you worked on it, when it breaks a week
later, it must be due to something YOU did, rather than the fact
that the chain was faulty or worn out and beyond repair anyway,
and that you only tried it in an attempt to help despite long
odds… Even when the customer DOES understand this, you still
then start seeing the damn thing over and over, with an
increasingly unsatisfied customer who sometimes loses confidence
in your ability… It’s your choice, but like I said, my
recommendation with chains like this is often to scrap it.
Peter Rowe