Hello, I wanted to solder the bail on the backplate of a pendant. Alas, as a result of wanting to make the pendant even with the bail I put a small metallic piece on the other side of the pendant. Horrible mistake. The metallic piece (Aluminium?) melt and made two stains on the backplate. Do you have any idea how I can remove them? Probably I can’t, right ? … thank you very much
I have not tried this myself, but Muriatic Acid (HCl) will dissolve Aluminum but will not touch the Silver.
It will form a thin layer of Silver Chloride that will easily be polished or brushed off though.
So maybe make a dilute solution of HCl and water and then drip it on the area affected and see if you can remove it this way?
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Thank You sooo much!!! Hit you mean it makes a Layer of Aluminium chloride, not silver? Bc in this case it may remove the texture and the Aluminium stays?
Good idea, bad implementation. Depending on how much one part needs to be raised from the other, you can use small titanium wire or strip pieces. Titanium won’t absorb solder, conduct a lot of heat away or melt and become one with your piece. You can also cut a small shelf into a piece of hard charcoal or just try to jig with a third hand. Yggdrasil gave you a possible solution to your current problem. It looks like the aluminum melted into the top of the baseplate, is it also melted into the bottom? You may have to remove so much of the baseplate to get rid of the aluminum that your design gets altered. It looks like you may have enough material to do this. Good luck and keep us posted…Rob
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As long as the Aluminum and Silver has not alloyed the HCl will remove all the Aluminum.
If it has alloyed your only option is to make a new or accept it and polish/brush it and let it be a part of the piece.
Maybe add more at other places to give it some interesting effects?
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Yes I had titanium strips but no, I had to take these unknown metal strips…. 
in fact in the meantime I already sanded the top part in the texture, it seems to be ok. Behind there’s a big bunch of lead but it’s ok, I keep this piece for myself…
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Yes. I could sand a part of it and it’s a moist invisible. I thought I could add another stain of this lead to make it “symmetrical “‘ in case nothing works. We always have to have a plan B, C, D……
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Some of my best pieces started out as a mistake. Good luck…Rob
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AMEN to That Rob!
Rosie
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Hello Indira8330
Just wanted to thank you for asking the question …and to all the Folk who replied
I have been ‘Messin’ with ( precious) Metals ‘ for a lot of years now
but never knew Muriatic Acid (HCI) dissolved Aluminium !
Always SOMETHING NEW to learn in our Wonderful shiney world.
I am a little bothered though …might the very thin sliver fine silver bezel wire , ( if used to set from the back )melt if exposed to the temperatures of some hot colour enamels? ( Reds, oranges ) ? Not having done much Enamelling myself , though I have read a lot…I Just wondered.
I wanted to add my voice to Rob’s too. Often some mishap has helped me transform an everyday piece into something really special and unexpected …sounds like this could be one of those times for You …can’t wait to see what you do with it !
If you’ve time for a little story…
Years ago a lovely old Lady Silversmith used to hire a bench in my workshop ….since retirement she had to share her own space with her husband (…who always seemed to want to eat …or have a cup of tea…) so she hired my double bench on my day off and sometimes shared it with a friend…to have a day off herself…she taught me many things but my favourite was a quote from her City & Guilds Teacher “There are no mistakes….Only Opportunities!”
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instead of acid, use a strong alkali… lye or sodium carbonate. Lye is better… it will quickly dissolve aluminum and leave other metals intact… doesn’t react with clean sterling silver…reaction results in the production of sodium aluminate… a water soluble material…must becareful since both lye and sodium aluminate are dangerously alkaline… it’s the same process that removes tarnish from silver using aluminum foil and baking soda… aluminum has a very high redox potential, will reduce tarnished sterling to fine silver… the only drawback to using this technique on silver plate is that it will reduce silver and copper oxides to fine metal that has to be polished, removing some of the plating… not good for repeated use.
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lead and silver make a mess!..you can remove aluminum with either a strong acid or strong base like lye… lead and silver alloy together…you cannot separate the two without destroying the piece.
separation of lead and silver is by cupellation!
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Thank You very much for your precious information! I didn’t know all that.
Hello Brightsmith, thank you! Yes there are only opportunities! I thought I could solder some balls on the other side but the drawback is that any hearing of a piece stained with lead (its lead and not aluminum, I’m sorry I was mistaken), the lead only extends as I could realize… by heating it the lead covered half the piece….
But it’s ok, I leave the stain, it’s an interesting pattern… wanted to make a zebra pattern but well… too complicated… :)) thank you for your very helpful feedback!
mistakes make for opportunity… spontaneous patterns created by mixed metals are often quite beautiful/ interesting… the lead will be dull, silver lustrous… don’t try to melt the lead off the silver… it will alloy. I made a similar mistake and ended up with a pile of grey ash… tried to overheat the silver to melt of the lead… the lead just ate into the silver, leaving a pile of lead/silver ash… moral of the story is lead and silver don’t mix… same goes for tin solders… tin won’t turn silver into ash but will alloy and won’t separate off using anything…the use of acids will work if the underlying metal is gold… gold is far less liable to alloy with lead and tin, and if not heated but just acid treated, the acid will burn off the base metals leaving acid resistant gold behind… HCl works well, but nitric acid does better but is far more dangerous… mixing nitric and muriatic acid (HCl) give aqua regia that dissolves gold… can’t mix those two acids without dissolving both gold and silver.