Trouble soldering end caps

Hi all!

I designed and cast a brass heavy-ish end cap to fit 5 lengths of
3.2mm brass snake chain. I’ve tried soldering 3 strands (every other
opening) using my medium silver paste solder, but haven’t gotten any
of them totally secured yet (so I haven’t bothered trying the last 2
yet). I can’t see or tell if the solder is flowing, and have charred
the heck out of all the components.

Does anyone have any experience getting multiple, close together end
caps soldered without destroying the separate parts? Any thoughts
would be greatly appreciated!

this may be crazy but are you try to solder each link in a seperate
session using just med solder? I was taught start with hard then med
then easy if doing multiple solderings on a piece.

Teri

It is okay to use medium solder for many times on the same piece. It
becomesa little bit harder to melt after the first time. Use careful
heat control and this will work. Just know that it does get easier
with experience!

Paste solder is harder to work with than hard solder. It sometimes
doesn’t hold well.

this may defeat the purpose of your caps but maybe piercing a slot
or design element so you can make sure the parts are all in contact
or solder the chain lengths together with hard solder then slump some
medium solder into the cap, flux the cleaned chain ends and reflux
the pool of solder and reheat making sure it is all as closely into
contact as possible. Remember solder isn’t gap filler! if there is
any space it’s never going to make a good join. You may have to
rethink your connection: the ends of all the lengths have to be clean
and as thoroughly in contact with each other as possible- so you may
need to flatten the chain lengths and solder them together creating a
solid “bar” on the cut edge, then using a file make sure the edge
that will contact the end cap is clean and will make a flush contact.
You may be able to use round nose pliers to tightly wind the edge
into a circle or appropriate shape that can fit into the cap and
make a good contact. If you are very concerned try hard solder to
bind the edges together than skip to easy solder to attach the
lengths to the cap- since its a base metal (brass) you can use less
expensive solder that has some strength (like “tix” brand easy
flowing solder) or yellow silver solder to try and match the colour.
I don’t work with base metals as a rule, but when I have had to (like
for a school group or scout troop wanting to trim metals costs so all
the kids could participate) cold connections were the easiest- so you
could try an end rivet once you have joined the lengths together- it
seems to me soldering each length to the cap wasn’t in your design
plan! so you may have to modify the cap rather than the overall
design using 5 lengths of chain, etc

Hi all

I solder end caps on 2 mm snake chain using hard solder paste no
problems.

Richard

Hi Richard,

My problem is that the end cap I cast in brass is heavy thick and
has holes for 5 different lengths of chain. Have you had any
experiences working on a piece of metal that big? I’m worried about
charring the whole thing and still haven’t gotten any single piece of
chain to solder (I think because it’s so thick).

Let me know what you think, thanks!
Sara

Sara, it sounds like you need to look at a couple of potential
issues. Is your torch flame hot enough? Are you using a protective
coat like Pripp’s or boric acid/alcohol to keep the piece free of
oxides before the solder flows? Are you using an easy flow solder?
You need to have everything clean and freeof all oxides, a flame big
enough to bring the cap up to temp quickly (keepit off of the
chain). Check that the flux you are using is suited for the work you
are doing, too. Paste flux may be more suited than the yellow
liquidas it holds up a little longer.

Melissa Veres, engraver and goldsmith

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Hi Sarah.

Ive disorder dropped in salt miss some of your earlier posts it
sounds like youre trying to solder several chains into a heavy end
cap.

I spent the first 12 years in the trade doing repairs. I used to
have to repair plaited stranded chains. Used to have to replait the
broken chain and then fit it to the end cap after. My suggestion
would be to solder the individual chains together before you put them
into the end cap. By doing this you decrease the chance of melting
any individual chain as you soldered into the end because the heat is
dispersed over all of the chains. To prevent the solder from running
along the chains you can put something like liquid paper on the chain
to prevent the solder from running along that section. You still flux
the end of the chains possibly using binding wire to hold them to
shape. I would then put a lower melting point solder into the end cap
and flow it in there. Put to the chain and the end cap together but
keep the heat mainly on the end cap. When the solder in the end cap
reaches melting point it will flow onto the chain. Still use liquid
paper on the chain as you solder it to prevent the extra solder from
the end cap, flowing too far back down the chain.

The other suggestion would be to use some sort of oxidisation
retardant. I use boracic acid suspended in methylated spirits. You
shake the jar with the methylated spirits and boracic acid in it and
drop the jewellery in there, this then burns off the methylated
spirits. This leaves a fine coating of boracic acid on the jewellery
so when you heated it, it fuses to the jewellery and prevents
oxidisation. Brass is particularly reactive so I think this would be
important. Once the brass has oxidised this becomes very difficult to
get the solder to flow.

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