Rio's medium sterling solder did not melt

Jewelry Discussion
1

I had an interesting problem last night trying to use Rio’s med
sterling solder. I made a loop in loop chain and fabricated some end
caps out of 18ga sterling so I could try to flush set some 2mm stones
around the barrel of the end cap.

I used Rio’s hard sterling solder for everything except soldering
the pin through the chain and end caps. I don’t use med solder much
so I used a piece that had been sitting around a while. I sanded the
solder’s surface shiny and placed 1 ball of solder on each joint
after using cupronil and borax flux. I heated the cap and pin to med
orange but the solder wouldn’t melt so I put the flame directly on
the solder, still nothing so I turned up the heat and got the end
cap shimmering and actually melted the end of the pin off right up
against the barrel and the med solder that wouldn’t melt.

I finally ended up fusing the pin or pulled hard solder that got
sucked out of the other joints. I had to file off the 2 balls of med
solder they never melted. I’m gonna dump the rest of the solder but
ANY idea what happened?? I only use hard and med solder both
unmistakably marked, I know I had med solder. I would appreciate any
conjecture.

Jim C Doherty

2

The fact that it balled up but didn’t flow suggests this. If you’re
certain that all the preliminaries were in place…cleaned etc, my
guess would be that despite being marked, your solder may not have
been solder afterall, coulda been a piece of sterling that got marked
by mistake.

Typically silver solder is yellowish compared to sterling,
particularly if its been sitting around for awhile. Might be worth
taking a second look.

3

Had you used that solder before? I once got a roll of hard or medium
solder from Rio that melted almost instantly wether there was
something wrong with that batch or it was mislabeled I’m not sure
but they exchanged it and even paid for the return shipping.

Dave Owen

4 
The fact that it balled up but didn't flow suggests this. If
you're certain that all the preliminaries were in place...cleaned
etc

I would suggest that the important question be asked. What kind of
torch was the person using? I’m thinking that the solder and metal
never got hot enough for the solder to flow. I find that this is the
problem with most of those who are just beginning to learn to solder.

5

Reading the replies to this post, all are feasible, I have had the
same problem ( lots of meltdowns). Upon investigation, I believe
that I was overheating the solder when balling it onto my solder
pick. I may be wrong but have been told that when medium or easy
solder are overheated, the zinc flashes off and the remaining metal
is then very difficult to flow. Since then I have been careful to
only get the solder to flow temperature when it is in place and even
then through indirect heating. I have not had any more problems with
my medium or easy solder

John Bowling

6

Hey All, more on the solder saga, Neil I am 100% sure I cut the
solder from the med wire roll. I can’t positively recall if I didn’t
put the solder down while I got my pliers to bend the shape I use to
identify the solder. If I did then I might have picked up sterling
wire but seems even sterling would have melted when I had the 18ga
end caps shimmering from the heat, but you might be right. David
thank you, it didn’t occur to me that the solder could be mislabled
or defective. I called Rio’s tech support was told the solder could
have been mislabled or a bad batch. He told me if the solder was not
right they would replace it and to let them know. I tried melting a
piece of medium and hard at the same time to see which melted first
but with a torch I am not sure if I am truly heating them evenly
enough to tell accurately. Any suggestions on testing the melting
temps of solders for someone without a pyrometer on their homemade
furnace? Fish, “the person” was using oxy propane with a Smith’s
little torch, #4 tip. I have been brazing jewelry for the last two
years. Thanks for the comments and suggestions

Jim C Doherty

7

Each supplier selling solder offers a wide and varied choices in
temperatures. I have found that Rio’s hard solder takes a tremendous
amount of heat to flow and even when you apply heat, it does not flow
consistently as well as other suppliers’ hard solder.

Although Rio Grande’s and Hauser and Miller’s hard solder has the
same flow temperature, Rio Grande’s seems to just ball up and be
almost mushy. It is not my first pick for hard solder, although their
easy and medium are fine and have consistent color match.

Hauser and Miller’s hard solder takes a tremendous amount of heat to
flow. Their alloy has a yellow tinge which does not match sterling as
exactly as I would like. However, in teaching students, it is a good
all around solder to use.

I have found that Hoover and Strong’s hard solder which has a higher
flow temperature, when heated flows beautifully and has an excellent
color match with sterling.

I don’t have the flow points for Otto Frei since I haven’t used
their silver solder, but I think their gold solder is quite good. I
don’t like Hoover and Strong’s gold solder, as it sort of blobs and
goes nowhere.

DH Fell’s solder is quite good, flows very nicely, color match is
very good, and takes less heat. However, look at the temperature
difference in “hard” solder between DH Fell and Hoover and Strong
which equates to a 125 degree difference. This is huge!

I did not realize there was such a huge difference in temperatures,
until I actually took the time to research all up the flow points for
silver solder from various suppliers. It answered a lot of questions
when I was fabricating, or when students were working. They thought
there was something wrong with the solder they purchased. I wrote
down all the info and post it on my bench when I order.

By listing some of the suppliers, you can see that the varying
temperatures will actually give you a larger range of Easy to Medium
to Hard.

I keep a large case of small containers which have every kind of
solder from every manufacturer and their flow rate listed on each
one. I realize that it is kind of OCD to do this, but it’s very handy
everything right in front of me.

I can’t stress enough the importance of documenting materials when
fabricating work.

Here are some useful tips in approaching soldering in fabrication:

  1. play around with your design and nail down your final sketch

  2. now de-construct your design into steps understanding what solder
    you will be using with which section. This is like an imploded
    drawing like you get at Ikea.

  3. document your progress as you build with what stones you chose
    and who you purchased them from, measurements and sizes of metal
    stock and vendor, pressure on a rolling mill if you used one, etc.

By going through these steps, when you need to build something
again, all your documentation will be done and you won’t spend YOUR
precious time re-inventing the wheel.

Silver Solder Wire Flow Points

Hoover and Strong Best color match to sterling silver

Easy 1250 F
Medium 1295 F
Hard 1490 F

Rio Grande Good color match in Easy and Medium

Easy 1325 F
Medium 1360 F
Hard 1450 F

Hauser and Miller Slight yellowing in their solder, but good for
beginners

Easy 1325 F
Medium 1360 F
Hard 1450 F

DH Fell Good color match and good flow for all solders. Just be
mindful of their temperatures if you are mixing one vendors with
another.

Easy 1240F
Medium 1275 F
Hard 1365 F

Hope this helps!
Karen Christians
Cleverwerx

8

Jim,

I ordered some easy solder from Rio last month and received fine
silver wire instead. So, if your solder didn’t melt, it probably
isn’t
solder. Rio was great about the problem. They sent a prepaid label
for
return shipping.

Marilyn O’Hara Studios
www.marilynohara.com

9 
Any suggestions on testing the melting temps of solders for someone
without a pyrometer on their homemade furnace?

Most moderately skilled people should be able to do pretty well by
putting metal/solder bits in a row and heating them - just to see
which melts first or last. Another way is to put it on a scrap of
metal - silver or clean fluxed copper would even do - and heat from
the bottom. Then you know it’s the metal heat that’s melting the
solder, and the diffusion of heat should be pretty even. Those won’t
give you a number, but you can see which goes first, last, or not at
all.