Results 1 to 8 of 8

Thread: Silver Soldering

  1. #1
    Join Date
    Feb 2018
    Posts
    5

    Default Silver Soldering

    I've had a good trawl through the threads on here relating to soldering problems, in the hope of finding a specific answer to my problem. However, no luck so far so here goes.

    I frequently have to solder a relatively small piece of silver to a much larger disc of solid silver and I am having problems getting any of the grades of solder to melt consistently. I follow all the necessary steps and have tried both borax and fluxed silverpaste with varying degrees of success. Frequently I can't get the solder to run at all and have to dismantle the job and clean everything before trying again.

    My gut feeling is the problem lies with a lack of heat. I am using a hand-held butane torch which seems capable of generating the required amount of heat but perhaps it is taking too long to get the work up to temperature and baking the solder in the process? I concentrate on heating the disc and I use pins inserted into a vermiculite board to support the work and prevent heat sink, but it is quite scary having to get it up to the point where it glows orange, as these discs are actually somebody's precious medal and I have nightmares about them dissolving into a molten blob!

    Here is a picture of a typical job which hopefully gives an idea of the what I am struggling with. Any help would be most gratefully received!
    Click image for larger version. 

Name:	DSC06708 - Copy.jpg 
Views:	27 
Size:	80.1 KB 
ID:	10914

    Spartan

  2. #2
    Join Date
    Sep 2014
    Posts
    2,067

    Default

    Are you getting the disc to turn red?
    Its possible that your torch isn't sufficient but the tricky aspect with this kind of soldering is the disparity in metal size which means you need to focus all the heat on the disc until it is hot enough then only a small amount of heat on the pins.
    If the disc is going a bright red you should have enough heat for the job.

  3. #3
    Join Date
    Feb 2018
    Posts
    5

    Default

    Hi Enigma

    Yes, generally I get the disc to glow nicely but sometimes I think I take too long to get there, by which time the pallion just turns into a black blob. I actually need surprisingly little solder on most jobs as the suspender ( the smaller piece) is an interference fit on the rim of the disc and only needs tacking in place. It's very frustrating when it doesn't run though!

    Clearly the amount of heat is crucial...too little and nothing happens, too much and I risk disaster!! But I'll keep trying. This how it looks when I get it right however:
    Click image for larger version. 

Name:	DSC06731.jpg 
Views:	19 
Size:	94.6 KB 
ID:	10916

    Spartan

  4. #4
    Join Date
    Feb 2011
    Location
    Scotland
    Posts
    3,392

    Default

    If you are using strip solder are you cleaning it first, solder doesn't tend to turn into a black blob?

  5. #5
    Join Date
    Feb 2016
    Posts
    99

    Default

    I had a similar problem when trying to solder an infinity bracelet.
    I solved my issue by hammering the solder into a flatter piece before heating; the larger flat surface area of the solder then absorbed the heat more quickly and ran.
    It also meant using even less solder for the job and quicker clean-up.

    Ceri.

  6. #6
    Join Date
    Dec 2009
    Location
    Central London
    Posts
    8,845

    Default

    I presume that the purpose of soldering is to join the three leafy claws to the edge of the disk and that the rest is assembled without solder.

    Everything must be cleaned and fluxed

    So leave the rest to one side, and fuse a little easy solder to the base of the three claws or leaves.
    Then use enough pins to keep them from moving and while lightly pressing the disk against them with tweezers or a probe, heat only the disk until the solder melts by conduction.

    This is sweat soldering and is the way to join something small to something much bigger. Dennis.

  7. #7
    Join Date
    Dec 2014
    Location
    South Australia
    Posts
    1,844

    Default

    Solder turning black is usually a sign something is not clean,
    If it just the pin you are soldering, why not just peen it over a polish without soldering

  8. #8
    Join Date
    Feb 2018
    Posts
    5

    Default

    Thank you everyone for the hints and tips.

    I assumed the reason for the solder blackening was the flux discolouring it, but it may well be that it isn't always clean enough. I do hammer strip solder flatter to try and make it easier to work with, but I obviously need to remember to give it a clean before I use it.

    Because the suspender takes the weight of the disc when it is hung from a ribbon, it's essential that it is securely fastened to the rim. On modern medals an additional small rivet passes through the base of the claw and the disc which helps secure it, but on earlier medals this is absent. So getting a good solder joint is essential.

    You have all been most helpful. I will follow your collective advice and hopefully crack the problem!

    Spartann

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •