How to best remove tin/lead from sterling silver knife handles and candle stick holders, etc?

[grainsofgold]

you should have done a HCl leach on the silver to get rid of the tin/lead before melting

Then a GOOD washing to get rid of the vast majority of the HCl leach used to rid the tin/lead

Then incineration to rid the traces of chlorides

Then ether dissolve the sterling with nitric - cement with copper to up grade the 925 silver (sterling) to (plus/minus) 998 silver - then melt/pour anodes to run in the silver cell --- or - pour anodes as 925 (sterling) & run direct in cell --- when running 925 direct in the cell you ether have to make your electrolyte with MUCH more silver dissolved in it to prevent co-depositing of copper - or change out the electrolyte more often to prevent copper co-depositing
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"The items in question are items made with a thin layer/sheet of sterling overlaying a lead/tin "filler" - such as knife handles &/or candle sick holders

The question was how to get rid of the lead/tin residue that is still stuck to the thin sterling silver sheet after melting away the "majority" of the lead/tin "inside" the "overlaying" sterling item
Kurt

Id like to start a new thread on this and move it from the previous- if this is not allowed please remove it - ​

If I understand correctly - lets say you are taking apart sterling silver knife handles and sterling weighted candle holders and other table top goods that have tin/lead metal as a filler-

Keeping this material separate - what's the preferred steps in getting rid of the tin/lead ?

1. Apply low heat so that the molten tin/lead runs off the sterling shells ( heat to only melt the filler material and leaving the sterling shells behind to process )

2. Boil the the sterling shells with the residual tine/lead on them in HCL ? ideal temp and how long on the heat?

3. Boil clean in Distilled water

4. Low heat applied to the washed shells to drive off the chlorides

5. Run through a cell or digest with Nitric/Distilled H20 then cement the silver ?

Thanks

GOG

 

[4metals]

what's the preferred steps in getting rid of the tin/lead ?

1. Apply low heat so that the molten tin/lead runs off the sterling shells ( heat to only melt the filler material and leaving the sterling shells behind to process )

2. Boil the the sterling shells with the residual tine/lead on them in HCL ? ideal temp and how long on the heat?

3. Boil clean in Distilled water

4. Low heat applied to the washed shells to drive off the chlorides

5. Run through a cell or digest with Nitric/Distilled H20 then cement the silver ?

I always consider that a refiner is in business to make money so additional steps are avoided like the plague. I know that knife handles and other similarly weighted sterling items are a pain to process already, they need to be cut open to expose some of the fillers and either let them fall out (if you are lucky) or remove the fillers mechanically.

Once opened I preferred heat. Keeping in mind that tin lead solders melt below 400ºF and sterling Silver melts at a bit over 1600ºF. Big difference! If you can keep a melt furnace below 750ºF you can melt the solder and pour it off. I prefer a bottom pour crucible for this.

To assure you can get most of the molten solder you can drain off the solder and shake the contents to allow any entrapped solder to flow freely and again try to pour off some solder.

I don't think you will ever get 100% of the solder out but if you get most of it any leaching and rinsing should be un-necessary.

The Silver should be then melted and cast into shot for cementing on copper. This will remove any remaining lead or solder and since most of the solder was melted out prior, there should be minimal I'll effects from the tin.

Any boiling in distilled water or heating to drive off chlorides is over-kill.

Another benefit of pouring any molten solder off comes from pouring it into a mold so if, or more frequently, when, a customer complains about weight losses you can at least hand them an ugly bar of solder to show them just how much Silver wasn't actually Silver.

 

[grainsofgold]

Thank you - Wasn't sure if the min amount left would be an issue or not-

I think I will still set these aside and run them as a separate batch - I'm working on a jog of sorts to remove the handles quickly and easier than slicing them in two parts- stay tuned

GOG

 

[FrugalRefiner]

I'm working on a jog of sorts to remove the handles quickly and easier than slicing them in two parts- stay tuned

I've always used Mr. Hammer. I hold the blade and set the handle so the seam is upright, then give it a couple of whacks. It usually does a pretty good job of breaking the solder joint between the two halves of the handle. I'm not sure how well it will work with solder filled handles. Mine have all been resin and cement type fillers.

Dave

 

[BGDOCK]

Side note :
I love that turpentine smell that come from plaster in the weighted silver items .

 

[4metals]

I've always used Mr. Hammer.

Maybe for a service for 8 set but when you get in a full drum of knives a hammer gets old real quick.

 

[galenrog]

Maybe for a service for 8 set but when you get in a full drum of knives a hammer gets old real quick.

Mr Hammer is my friend. And is emotionally satisfying.

 

[BGDOCK]

To quote Mc Hammer

“ It’s Hammer Time “

 

[nwinther]

The Silver should be then melted and cast into shot for cementing on copper. This will remove any remaining lead or solder and since most of the solder was melted out prior, there should be minimal I'll effects from the tin.

I don't understand this (my bolds). What will the shot cement on copper? You dissolve before cementing, right?

 

[Yggdrasil]

I don't understand this (my bolds). What will the shot cement on copper? You dissolve before cementing, right?

After making shots it are dissolved and cemented on Copper.
What ever remaining base metals will not cement on the Copper.
Just make sure to remove whatever Metastannic acid are in there first.

 

[4metals]

I don't understand this (my bolds). What will the shot cement on copper? You dissolve before cementing, right?

I mentioned shot because the material will dissolve more efficiently because shot has more surface area to aid in the dissolving process. Yes dissolving and filtration must precede cementation.