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 Replies: 30 / Views: 6,472 |
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Bedrock of the Community
United States
20753 Posts |
Quote:
Direct the heat to where you want the solder to flow. Muriatic acid is supposed to take it off IF it is soft solder. Careful not to melt your coin entirely! Try sawing out as much as you can and use needle files for the rest.
Muriatic Acid and a file? May as well use a wire wheel at about 1845 RPM. For sure that will really do some damage. |
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Pillar of the Community
United Kingdom
2624 Posts |
There are different grades of solder which melt at different temperatures... the hard solder is very close to the melt temp of the actual metal so it would require some skill to judge how much heat you put in so as not to "sweat" the metal around the solder.
As mentioned the solder will flow towards the heat so it is possible to draw it off using another silver object... for instance a thick piece of metal maybe 1mm thick and 2 mm wide and quite long with a tiny hole in it if placed on top with the heat source behind it would draw some of the solder through...(this piece it is essential to get it hotter than the coin without melting it)
Performing a task like that repeatedly would remove solder but blacken the coin with soot...then you would have to pickle the coin in something like ammonia etc...from a numismatic point of view it all seems a bad idea.
Solder is slightly softer than the metal, it could be possible to file it down so that minimal remains, then heat behind the coin (from the other side) it would just run flat and any file marks would dissapear as the surface tension would flatten the solder. Its possible that it would still be visable though in the form of slight discolouration.
Really as has been advised it would be best to leave it for the sake of the coin. The acid idea is a new one to me, while it is true that "pickle" is used in a jewelers (sulphuric acid or safety pickle) that is usually used to remove excess flux and soot etc. Solder itself is normally assay quality with other lower melting materials added so that it melts before the metal, anything strong enough to eat it will presumably also eat the coin.
If the coin is simply to be used as jewelery then to use a dentist drill with appropriate grinding attachment would be the best way to go and then to go through the grades from course to fine and then polish out...you could undoubtedly lose some grades on the coin though.
Edited by DavidUK
07/29/2012 8:37 pm
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Bedrock of the Community
Australia
21788 Posts |
Not keen on the acid idea.
A 90% gold couin has 10% alloy, usually copper. The copper would be leached out of the surface of the coin leaving the gold behind.
Some sign of acid attack would remain.
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Pillar of the Community
 United States
619 Posts |
The acid didn't do much good by itself. I read somewhere else to add peroxide. I tried that for a while, and that dissolved most of the solder. It looks better, but still not perfect. No big deal, it's just bullion.
Edited by CPC24
07/31/2012 1:09 pm
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Valued Member
Canada
135 Posts |
The solder is on there for good.
The only hope you could of had is to heat the coin/solder to the solders melting point then drop into cold water.
The cold shock would instantly harden the solder before the coin cools and if your lucky the solder would pop right off after the coin contracted.
If the coin had scratches on it, it makes it extremely difficult or impossible to remove. If it was smooth, you may of had luck.
It sounds like you may have removed too much solder already to try that trick, I don't know.
Like you say it's bullion with just PM value so I would not worry about it now.
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Pillar of the Community
United States
619 Posts |
I had the coin acid tested. Apparently, it's a fake.  I took it back to the guy, and he didn't believe me. He then checked another coin he had just like it, and it was fake, too! Apparently whoever sold them to him ripped him off. He finally had to give me my money back. I felt bad for him, but he really needs to check his purchases better. Edited by CPC24
08/11/2012 9:29 pm
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New Member
47 Posts |
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he really needs to check his purchases better. As do you. You're lucky that you got your money back! In the future if you need to get solder off of anything. Have a small art paint brush ready dipped in lead free plumbing flux, take a torch to heat until solder melts. Once melted, sweep the brush from center toward edge while continuing with torch. Apply more flux to brush if needed until all gone. Edited by wayforwarded
08/11/2012 11:41 pm
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Pillar of the Community
Canada
598 Posts |
I just got this at not much above spot...   I really want the mount removed. I also searched here and found these quite successful attempts at solder removal from gold with acid... https://goccf.com/t/135785https://goccf.com/t/135907And, I have seen some very intricate coin cutout artwork by another CCF member posted (I will search for said posts momentarily). Problem is, that the solder on this mount appears to be gold. I have only looked, not scratched or anything else. For the coin cutout art work... is it a very fine coping saw blade?... or, well, suggestions appreciated. ... but, please refrain from "take it to a jeweler". I'd prefer you to tell me what a jeweler would actually do instead.  >>> edit >>> Coin is Finland 10 Markkaa 1879S & nohope is the coin art cutout person!... your thoughts?  Edited by IBGolden
02/01/2013 9:29 pm
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Pillar of the Community
Canada
3692 Posts |
Lol, IBGolden, take it to a jeweller.  A good one with a reputation for high quality repairs. Can people be more specific when they generically say "acid"? I'm talking about muriatic acid. The flux idea is good but the hairs will burn off to a nub. Use a titanium wire instead. (I'm mostly believing DavidUK and sel's advice - mostly because I know they know what they're talking about from reading other posts.) It's funny how people are worried about the condition of the soldered coin after a repair since the solder has already made it too far gone anyways - it's already damaged to begin with, especially now that we know it's a fake. Go to town with it now; it's a (bad) copy. Edited by Libertad
02/01/2013 9:45 pm
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Valued Member
United States
318 Posts |
I collect 2 pesos also. I didn't know they were faked. Great, one more darn thing to worry about.
Is it possible your coin guy has bad acid? Years ago when I was hard up for money I had to sell my old class ring. The first pawn shop did an acid test and told me it wasn't real gold. The next place tested it, found it real, and paid me.
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Bedrock of the Community
United States
20753 Posts |
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Pillar of the Community
United States
1721 Posts |
IBGolden,
That was my thread, and yes you can remove solder from a gold coin using acid. However, you CANNOT use acid to remove gold solder from a gold coin. The solder I removed from my coin was silver solder. The silver testing acid (Nitric?) dissolves the silver but won't harm the gold (in my opinion). In your case, I believe the only two ways are cutting off or melting off. Once the coin is heated for the removal, it will leave a big black spot. And there will be portions of solder that have merged, fused or bonded into the coin. You'll never get it off unless you want to leave huge voids. You'll notice the void on my coin from the silver fusing with the coin.
Instead, have a jeweler repair the top of the attachment and enjoy it for what it currently is. A piece of jewelry.
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Pillar of the Community
Canada
598 Posts |
Sooo, this morning I prepared myself with my 50X microscope, rubberized mats, my hobby light, a variety of small cutting tools, including needle files and dental picks(I'm an electronics technologist so small tools I've got)... and did a long survey of the coin above before proceeding to remove the mount... But, before I got all small with it, I pressed a small xacto knife between the solder bead and the mount... not between the coin and the solder bead... ...AND SNAP! Horrified & confused I quickly grabbed the scope to go in for a closer look...  To my astonishment the mount easily broke away from the solder by pressing the xacto knife between the mount and solder... it clicked/snapped away cleanly! I didn't even apply more than a few pounds of force. The mount simply has a stain where the solder was attached. I was amazed/pleased that all four solder points let go in this manner.  Now, with scope all a jitter, the solder is obviously silver/grey in colour. There was just such a tiny amount of solder first visible that it took on the colour of the surrounding gold, but now that it is separated, it is clearly not gold in colour. I was also able to pick some solder away from the coin edge leaving an impression of the coin reeding(in the solder)... but not all of it. The central points probably got better heat, and a better bond. Now I have four tiny points of solder to remove from the coin edge... and I mean tiny... small enough I was thinking of letting sleeping dogs lie. But, I'm sure I could take hours/days and clean the rest off reed by reed... but I'm feeling very lucky now... SO, mds308, can you get me a line on the acid you used >>> edit >>> soaking in vinegar rite now & solder is definately grey now!  Edited by IBGolden
02/16/2013 2:30 pm
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Pillar of the Community
United States
9793 Posts |
Bad Thad - you owe me a new laptop! I am at Starbucks between work shifts today on CCF. I just sprayed coffee all over the laptop while actually LOLing (yes people stared at me funny) as soon as I saw your post. Nothing else needed to be said at that point. Now to get some wet napkins and clean this sticky keyboard. Thanks for the laugh today, I needed it.
Glad to hear the solder issue solved itself with a little elbow grease!
"Buy the Book Before You Buy the Coin" - Aaron R. Feldman - "And read it" - Me 2013! ANA Life Member #3288 in good standing since 1981, ANS, Early American Coppers Member (EAC), Colonial Coin Collectors Club member (C4), Conder Token Collector Club member (CTCC), Civil War Token Society (CWTS) member, Liberty Seated Collectors Club (LSCC) & Numismatic Bibliomania Society member (NBS), USMex, Member in good standing, 2¢ variety collector. See my want page: http://goccf.com/t/140440Edited by westcoin
02/16/2013 5:33 pm
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Valued Member
Canada
286 Posts |
I didn't see this mentioned but when soldering old electronics I use a soldering wick to remove excess solder. You can make one with any cheap wiring you might have laying around just strip it and braid it then flatten it.
Heat the solder with the gun then hold the wick to the solder the remove it. Do not remove the gun during this process. That should remover everything.
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Replies: 30 / Views: 6,472 |
First Page
Posted 07/29/2012 7:35 pm
