Misadventures as a coin doctor
MtMan
Posts: 47
After reading many threads in which people oooh'd and ahhhh'd over "monster" toned coins that looked questionable to me, or drooling over coins that I was assured by others were altered, cleaned etc. I decided it might be time to get some first hand experience with altered surfaces. For those of you who think my motives are less than wholesome, well ... I can't say I blame you but I have never sold any of my coins and I don't intend to start anytime soon. If I did I would be sure to mention any alterations. That being said I thought I would share with you my first misadventures as a coin doctor.
For now at least I've decided to give dipping a pass altogether as it removes a small layer of the coins metal along with the tarnish. Instead I decided to try a reducing method that I've read about on this board. Rather than removing the tarnish from a silver coin this method uses a chemical process that causes the sulfur in the tarnish to be released and to bond with the aluminum thereby leaving the silver on the coins surface. I won't go into the chemistry of the process at this point but I can provide more details if anyone is interested.
Experiment #1a:
I selected two heavily tarnished silver alloy coins for this experiment; a walker in vf and a silver clad Kennedy in AU.
In this experiment the silver coins were placed in a foil lined pan.
Boil ~ 1 qt of water then add 1/4 cup baking soda
carefully pour mixture into foil lined pan
Let sit for 5-10 min
Result: No visible change
Comments: I thought perhaps that since the foil was only contacting the high points of the coin where little or no tarnish was present that I needed an
aluminum surface that could conform more closely with the coins surface.
Experiment #1b:
In this experiment I used the same coins and procedure as in #1a but rather than foil I placed the coins in a pile of pure aluminum micro-spherules that I
purchased from Aldritch. The thought behind this was that the aluminum particle could get between even the smallest devices on the coin thereby allowing
the reducing process to take place evenly over the entire coin surface.
Result: No visible change
Comments: I have two thoughts for my next attempt at a reducing reaction:
1) Try washing soda rather than baking soda. I've read it works better.
2) Try experiment with pure silver to verify process. I have some tarnished silver ingots that I may try this on.
Having so far struck out with removing tarnish I decided to try adding some, otherwise known as AT.
Experiment #2:
In this experiment I decided to try some good ol' fashioned potato baking. As my test subjects I used three common date circuled mercs with clean
surfaces.
One coin was coated with vege oil, one with olive oil and the other was left uncoated.
Each coin was then placed in a slit in the top of a red potato (I didn't have any baking potatoes around)
Each potato was wrapped in foil then baked in the oven at 300 F for 1 hr and 40 min.
Results: No discernable toning on the coin coated with olive oil. On the coin coated with vege oil there was very minor gold brown toning overall with the
exception of a black streak down the reverse. The best results (relatively speaking) came from the uncoated coin. This coin had a noticeable mottled gold
brown toning pattern. I wouldn’t go so far as to call it attractive but it's a start. The only problem is getting the potato off the coin without the protective oil
coating. Oh well a least I have some baked potatoes.
Comments: I may try this again with a longer bake time and/or higher temp. I would also suggest inserting the coins horizontally into the coin rather than
vertically so that the oil does not run down the coins surface and cause streaking. Lastly I would like to advise that you not eat the part of the potato
that touched the coins, its yucky.
Conclusions: There is no danger of me pulling a fast one on anyone anytime soon so put down the pitchforks.
Coming up next: Belt Sanders; what grit?
For now at least I've decided to give dipping a pass altogether as it removes a small layer of the coins metal along with the tarnish. Instead I decided to try a reducing method that I've read about on this board. Rather than removing the tarnish from a silver coin this method uses a chemical process that causes the sulfur in the tarnish to be released and to bond with the aluminum thereby leaving the silver on the coins surface. I won't go into the chemistry of the process at this point but I can provide more details if anyone is interested.
Experiment #1a:
I selected two heavily tarnished silver alloy coins for this experiment; a walker in vf and a silver clad Kennedy in AU.
In this experiment the silver coins were placed in a foil lined pan.
Boil ~ 1 qt of water then add 1/4 cup baking soda
carefully pour mixture into foil lined pan
Let sit for 5-10 min
Result: No visible change
Comments: I thought perhaps that since the foil was only contacting the high points of the coin where little or no tarnish was present that I needed an
aluminum surface that could conform more closely with the coins surface.
Experiment #1b:
In this experiment I used the same coins and procedure as in #1a but rather than foil I placed the coins in a pile of pure aluminum micro-spherules that I
purchased from Aldritch. The thought behind this was that the aluminum particle could get between even the smallest devices on the coin thereby allowing
the reducing process to take place evenly over the entire coin surface.
Result: No visible change
Comments: I have two thoughts for my next attempt at a reducing reaction:
1) Try washing soda rather than baking soda. I've read it works better.
2) Try experiment with pure silver to verify process. I have some tarnished silver ingots that I may try this on.
Having so far struck out with removing tarnish I decided to try adding some, otherwise known as AT.
Experiment #2:
In this experiment I decided to try some good ol' fashioned potato baking. As my test subjects I used three common date circuled mercs with clean
surfaces.
One coin was coated with vege oil, one with olive oil and the other was left uncoated.
Each coin was then placed in a slit in the top of a red potato (I didn't have any baking potatoes around)
Each potato was wrapped in foil then baked in the oven at 300 F for 1 hr and 40 min.
Results: No discernable toning on the coin coated with olive oil. On the coin coated with vege oil there was very minor gold brown toning overall with the
exception of a black streak down the reverse. The best results (relatively speaking) came from the uncoated coin. This coin had a noticeable mottled gold
brown toning pattern. I wouldn’t go so far as to call it attractive but it's a start. The only problem is getting the potato off the coin without the protective oil
coating. Oh well a least I have some baked potatoes.
Comments: I may try this again with a longer bake time and/or higher temp. I would also suggest inserting the coins horizontally into the coin rather than
vertically so that the oil does not run down the coins surface and cause streaking. Lastly I would like to advise that you not eat the part of the potato
that touched the coins, its yucky.
Conclusions: There is no danger of me pulling a fast one on anyone anytime soon so put down the pitchforks.
Coming up next: Belt Sanders; what grit?
0
Comments
<< <i>Experiment #2:
In this experiment I decided to try some good ol' fashioned potato baking. As my test subjects I used three common date circuled mercs with clean
surfaces.
One coin was coated with vege oil, one with olive oil and the other was left uncoated.
Each coin was then placed in a slit in the top of a red potato (I didn't have any baking potatoes around)
Each potato was wrapped in foil then baked in the oven at 300 F for 1 hr and 40 min.
Results: No discernable toning on the coin coated with olive oil. On the coin coated with vege oil there was very minor gold brown toning overall with the
exception of a black streak down the reverse. The best results (relatively speaking) came from the uncoated coin. This coin had a noticeable mottled gold
brown toning pattern. I wouldn’t go so far as to call it attractive but it's a start. The only problem is getting the potato off the coin without the protective oil
coating. Oh well a least I have some baked potatoes.
Comments: I may try this again with a longer bake time and/or higher temp. I would also suggest inserting the coins horizontally into the coin rather than
vertically so that the oil does not run down the coins surface and cause streaking. Lastly I would like to advise that you not eat the part of the potato
that touched the coins, its yucky. >>
OK, potato toning, I know about that. Yes, getting the potato off the coins is a pain. I have read, the proper way is to dip the coin in corn oil, wrap the coin in foil and insert it into the potato. With my experiment, the coins did not start to turn any color until after 2 hours
Im done with this.
____________________________
<< <i>Coming up next: Belt Sanders; what grit? >>
My co-workers think I'm crazy because of all the secretive giggling.