RCH07

As a former engineer in the metals industry, I've been following this thread with some interest. FWIW, I would not try any of the methods suggested. I also would suggest you not "play with the solder". If you don't know what you're doing you will ruin the coin. This may not matter since you haven't revealed what the coin is (gold, silver, copper) and the piece may be of low value. If it is and you don't mind the likely outcome, go for it. Otherwise either leave it alone or send it to the pros - Stockton or NCS. They have the techniques to do this properly with the edge going to NCS.

Thanks for the excellent feedback. I believe I did identify the coin in an earlier post as a Dime from Hawaii, dated 1883 and is in what I would call AU condition. I also believe that the coin is silver. I am not going to attempt to remove the solder as I too believe that I would most likely ruin it. I don't know what the value of this coin is but I will leave it alone in any case. Should I find that it is of some high value I might send it out to one of the shops you have recommended.

Thanks Bob

With all due respect to everyone here who guessed at how to remove the solder, they are all dead wrong. Do not attempt to heat the area of the solder with an iron. When coins are soldered in jewelry applications, the method is brazing and it is done with a torch or in an oven. The solder attached to a silver coin is almost always silver and is almost always hard solder, or .800fine. Soldering silver requires heating the entire piece to solder flow temperature because silver is the best conductor of heat of any metal, and heat sinking is difficult on anything other than light wire or shank stock. Removing solder from a piece of .900 fine silver whether it's a coin or a piece of jewelry should only be done by a qualified silversmith.

 

Also, be aware that heating the coin to the stage of red heat necessary for causing the solder to flow so that it can be vaccumed up with a bulb will also cause the copper in the alloy to bloom and the coin will then have to be pickled in a heated acid solution to return it to its silver color. Glazing the coin with a boric acid/ethanol solution will reduce the copper bloom, but will also have to be removed by pickling. Removing the solder is going to reduce the eye appeal of the rest of the coin which doesn't have the solder on it.

 

You should send it off to be restored or leave it alone, but trying to melt the hard solder with a soldering iron will not work and will cause discoloration.

More great feedback. As I don't want to ruin the coin and It would appear that I most likely don't have the equipment necessary to properly remove the solder perhaps I should just leave it alone. I don't know the value of the coin but I guess that I could most likely just reduce it by playing with the solder.

Bob, If you're going to do it, get some copper braid solder remover from an electronic supply. You heat it on the solder and it is more recieving of the solder than the host. Mike

thanks for the tip. I'll try it. once I have completed the surgery I will take a photo of the coin and post it on my Omnicoin site.

There is also a process using acid to take the babbitt (sp.) from bearings off the supporting surface. You may be able to learn more about that be doing a Google search.

 

I would like to thank all that have contributed to my request for information. I believe that I will attempt removal using a soldering iron and a very soft brush or cloth. If this doesn't work I will just leave it alone.

 

Thanks again

Bob

Blow torch or arc welder but then the coin will go with it naturall. Question is how do you know it's solder? What type of coin is it. solder sticks to metals depending on what type of metal it is. Very soft metals will adhear to solder well again pending on which metals and which solders. There are just as many types of solder as there is types of metals to make it with. Some don't even have Lead in the mixture and some are pure Lead. The so called lead may just be glued in place if part of the original jewlery. If this is a valuable coin, leave it alone. If it is just an average coin, try removing it with a soldering iron and only at the location of the contaminate. However, if a very soft type of solder and a soft metal coin, the solder will spread when heated so make sure it is not a valuable coin.

Further you may try just putting solder on the rest of the coin to make it all even.

I am not sure what the joke is, but my question was serious and I am looking for some suggestions as to how to remove the solder. I believe that I will attempt to remove it with the soldering iron and a soft brush.

As to the value of the coin, I don't know just how much it might be worth but I tend to like the coin and don't want to ruin it. The coin is a Dime from Hawaii, dated 1883 and is in what I would call AU condition.

Thanks for your suggestions.

Hello All;

I have a coin that was installed in some jewlery at one time and I am wondering if anyone has any idea how to remove a small amount of solder left on the coin. The solder remaining is very small and only in one location on the rim of the coin.

Thanks