removing solder from a bust half?

[delta]

In a recent discussion this topic was mentioned, but it was a false alarm, and solder was not the issue.

 

Here's a decent 1825 CBH with solder I'd love to remove. It seems there may originally have been two dabs of solder, and maybe the one at left was mostly removed, leaving just a thin coating. The other over the right wing to the IC of America contains a big gob.

 

There is apparently no conspicuous damage to the underlying coin so far.

 

Any way to get rid of this adherence without affecting the coin? I'd prefer a dip that might dissolve away the solder only.

 

[BillJones]

I don't think that there anything you can do about this that will remove the solder without leaving a mark. The coin is unfortunately damaged and can't be repaired.

[physics-fan3.14]

You will see clear evidence of solder removal in that the toning will be quite different.

 

What I would recommend would be to heat the coin very gently (not entirely sure how...) Solder has a very low melting point, at a temperature that will do no damage to the coin. When the solder has liquefied, remove it (a blotting sponge should do the trick - just make sure that it is very clean and free of metallic bits - you don't want to potentially scratch the coin).

 

After the solder is removed, very quickly and very gently dip the coin. Wash thoroughly to remove all traces of dip. The dip is to basically "reset" the toning - you will have very ugly blank splotches and very dark toning otherwise, and the coin will be very unappealing.

 

After the quick bath, place the coin in an album or envelope of some sort, and leave it somewhere safe for 20 years. Check it every couple of years to make sure its going well. When it is done, it should have a decent patina - you'll be able to tell its not completely original, but assuming there is no underlying damage, it should look ok.

 

This is entirely theoretical - I've never done something like this. But, it would seem to make sense to me.

[jpcienkus]

If you do follow Jason's advice and decide to gently heat the coin, please go to an electronics store and find a solder wick. They make solder "suckers" as well, but those are used for small defined areas. The wick will absorb the solder and hopefully do so without scratching the coin in anyway.

 

Good luck. Should be a good test for steady hands.

[delta]

I don't think that there anything you can do about this that will remove the solder without leaving a mark. The coin is unfortunately damaged and can't be repaired.

 

Thanks for replying. I realize that's the usual wisdom, but am hoping for a new development.

[delta]

Many thanks for the ideas, I can imagine heating the coin inside a toaster oven, or in a high boiling point liquid such as heavy mineral oil, what do you say?

 

As for the underlying toning, is it possible in this case it might not have been affected, or only in a microscopic way?

 

 

You will see clear evidence of solder removal in that the toning will be quite different.

 

What I would recommend would be to heat the coin very gently (not entirely sure how...) Solder has a very low melting point, at a temperature that will do no damage to the coin. When the solder has liquefied, remove it (a blotting sponge should do the trick - just make sure that it is very clean and free of metallic bits - you don't want to potentially scratch the coin).

 

After the solder is removed, very quickly and very gently dip the coin. Wash thoroughly to remove all traces of dip. The dip is to basically "reset" the toning - you will have very ugly blank splotches and very dark toning otherwise, and the coin will be very unappealing.

 

After the quick bath, place the coin in an album or envelope of some sort, and leave it somewhere safe for 20 years. Check it every couple of years to make sure its going well. When it is done, it should have a decent patina - you'll be able to tell its not completely original, but assuming there is no underlying damage, it should look ok.

 

This is entirely theoretical - I've never done something like this. But, it would seem to make sense to me.

[delta]

Thanks much! Might the solder wick do its work inside a superhot liquid such as heavy mineral oil? How about just laying a small strip of the solder wick across a coin to then be heated inside a toaster oven, on an oven proof piece of ceramic?

 

I think we're on the way to finding a technique worth trying. If only we had a bunch of these CBHs needing solder extraction it would be more worthwhile to do preliminary experiments. We could employ 90% silver halves being sold for bullion by face value, thus risking nothing numismatic. Then add solder to the coins and practice different removal techniques. Has someone already tried those experiments?

 

If you do follow Jason's advice and decide to gently heat the coin, please go to an electronics store and find a solder wick. They make solder "suckers" as well, but those are used for small defined areas. The wick will absorb the solder and hopefully do so without scratching the coin in anyway.

 

Good luck. Should be a good test for steady hands.

[Coindude]

As Joe mentioned above, the solder wick should help and here's a video showing the use of a solder sucker, quite interesting.

 

[jpcienkus]

Delta,

 

I wouldn't use a toaster oven, I'd try a soldering iron. That way you can heat only the area with the solder and use your other hand to remove the solder with the wick.

 

Edited to add: as stated before, solder has a low melting point. You will only need to heat small areas to get it to flow.

 

Back in college, I stuffed PC boards. Made my fair share of mistakes, but got proficient using the tools of the trade.

 

Joe

[Conder101]

First see if you can scratch that lump of solder with something not much harder than your fingernail. If you can then you just might be able to improve it some. If the solder scratches easily it's a lead or lead/tin based solder and it will have a low melting point, around 500 degrees. In that case the soldering iron and solder wick or a "solder sucker will remove much of the solder, but probably not all of it.

 

If it DOESN'T scratch real easily, then it is a silver solder and the melting point is in the 1300 to 1500 degree range. For that you will need a serious torch. A soldering iron AIN'T gonna do it. And since you are now only a couple hundred degrees below the melting point of the coin, you are very likely to do some serious damage to it as well.

 

The lead or lead/tin based solders are used for electronics or plumbing. Applications where electrical conductivity or spece filling were needed but not structural strength. Silver solder is used for jewelry or applications where the solder has to provide part of the structural support in the item. This coin had a pin soldered to it, a jewelry application. So the chances are good this will be a silver solder.

[delta]

Thanks again Joe for more pointers. Okay, nix on the toaster oven, it was just a careless thought.

 

Delta, I wouldn't use a toaster oven, I'd try a soldering iron. That way you can heat only the area with the solder and use your other hand to remove the solder with the wick. Edited to add: as stated before, solder has a low melting point. You will only need to heat small areas to get it to flow. Back in college, I stuffed PC boards. Made my fair share of mistakes, but got proficient using the tools of the trade. Joe

[delta]

Valuable info, much obliged, will follow those guidelines, with my fingernails to begin with. Haven't yet removed the coin from its 2 X 2, am keeping all my options open for another day or two, while still hoping to obtain more replies, perhaps from someone who successfully desoldered their early U.S. large U.S. silver coins.

 

 

First see if you can scratch that lump of solder with something not much harder than your fingernail. If you can then you just might be able to improve it some. If the solder scratches easily it's a lead or lead/tin based solder and it will have a low melting point, around 500 degrees. In that case the soldering iron and solder wick or a "solder sucker will remove much of the solder, but probably not all of it.

 

If it DOESN'T scratch real easily, then it is a silver solder and the melting point is in the 1300 to 1500 degree range. For that you will need a serious torch. A soldering iron AIN'T gonna do it. And since you are now only a couple hundred degrees below the melting point of the coin, you are very likely to do some serious damage to it as well.

 

The lead or lead/tin based solders are used for electronics or plumbing. Applications where electrical conductivity or spece filling were needed but not structural strength. Silver solder is used for jewelry or applications where the solder has to provide part of the structural support in the item. This coin had a pin soldered to it, a jewelry application. So the chances are good this will be a silver solder.

[delta]

Incidentally, I've belatedly just attributed this 1825 half, it's O-115, an R3, and I'd otherwise grade it XF 45. Unsoldered it lists in the NGC price guide as $235.

 

Shouldn't the value of the underlying coin affect how it gets treated?

[RWB]

At present, your coin has little value. With the solder removed, it might be of interest to some collectors.

 

I have seen silver and gold coins from which ordinary solder has been removed and the results range from excellent to awful. The copper pieces I've seen (few) were uniformly awful. As others noted, skill is required. Take it to a manufacturing jeweler.