Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 25

Thread: Problems with rolling 9ct gold

  1. #11
    Join Date
    Jun 2017
    Posts
    34

    Default

    So I'm still having the same problem.
    I've been slowly heating it till just gone slightly red then hold it for around another 10/15 seconds...leave it for 19 seconds or so then quench.
    It seems that by the time I get to the 3rd size of the round rollers the gold is quite curved/bent and just starting to show signs of cracking, annealing frequently inbetween.
    I might contact the local jeweller and and ask if he could kindly show me or even take my gold there to see if there's any problem with it.

  2. #12
    Join Date
    Sep 2014
    Posts
    2,050

  3. #13
    Join Date
    Jun 2017
    Posts
    34

    Default

    I can only assume so as I haven't done annealling before. I have read a lot of ways to do it and watched countless videos on it.
    The only thing I'm not doing is pickling it.
    I do all my work at my home so I wasent going to pickle until the end product (I haven't used pickle before by the way, when sandcasting rings I've just had to file sand and polish)

  4. #14
    Join Date
    Jul 2010
    Location
    The Netherlands
    Posts
    388

    Default

    Quote Originally Posted by Simmo View Post
    I can only assume so as I haven't done annealling before. I have read a lot of ways to do it and watched countless videos on it.
    The only thing I'm not doing is pickling it.
    I do all my work at my home so I wasent going to pickle until the end product (I haven't used pickle before by the way, when sandcasting rings I've just had to file sand and polish)
    What is the original source of your scrap 9 ct gold?

    Sent from my SM-T520 using Tapatalk
    Poor old Les

  5. #15
    Join Date
    Sep 2014
    Posts
    2,050

    Default

    If its annealed correctly it should be fairly malleable straight afterwards.

  6. #16
    Join Date
    Jul 2010
    Location
    The Netherlands
    Posts
    388

    Default

    Not an expert here but from my limited metallurgy knowledge here are my thoughts:
    Melting metal too hot will make an unstable brittle ingot that no amount of annealing will solve. Oxygen contamination will produce a brittle ingot. Hammering before rolling is important. Annealing temperture, length of time and type of flame.

    Sent from my SM-T520 using Tapatalk
    Poor old Les

  7. #17
    Join Date
    Jun 2017
    Posts
    34

    Default

    I get most of my gold from eBay. I've seen quite a few people disagree with getting it from there but I test everything before I use it and I've made items before and had them hallmarked in the uk just fine.
    I haven't tried hammering the ingot so I may try this.
    Over melting may be a cause too as I only check the kiln every 20 minutes to see if it's melted enough.
    Oxygen contamination...I know nothing about.

  8. #18
    Join Date
    Aug 2017
    Posts
    232

    Default

    I am a betting man and my money is on the impurities causing the problems. You buy scrap gold which probably contains a lot of solder joints. Zinc is a component of solder and it is the only metal generally used in 9ct gold described as being "hard and brittle at most temperatures."

    I don't profess to be an expert, but from everything you say it makes the most sense to me and also explains why the suggestion is to add pure gold to your scrap. The purpose, I expect, is to dilute any zinc in the scrap in order to make it less susceptible to the very problems you are experiencing.

    Zinc...my money is on the zinc!

  9. #19
    Join Date
    Jun 2017
    Posts
    34

    Default

    Thanks for the advice everyone. I think I'll just cast another ring from this batch and have a go at milling with the next lot of gold I get.
    ...or look up how to extract the zinc from it.

  10. #20
    Join Date
    Jun 2017
    Posts
    34

    Default

    So I've tried it again and...it's working for me better now.
    I've been using a typical wire ingot but it's so hard to try and pour into the smallest wire hole, some of the gold goes in but most seems to fall over the side.
    I only manage to get the wire ingot full half way around 1/10 attempts.
    But it's rolling much better and annealling it has got to plan each time. It just seems to work better for me with thinner metal.
    Only problem I've come across now is just when I'm getting to the thickness I would like (for a basic ring band) the metal seems to curve off to the side.
    This may be fixable through hammering on the mandrel once I've shaped and soldered it together

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
  •