Subject: Silver plating - a bit nearer.

From: Marc Line <[email-masked]>
Date: Tue, 23 Apr 1996 08:33:02 +0100

In article <[email-masked]>, Robert Galloway
<[email-masked]> writes

>I have done a lot of plating in the scale you describe.  I used a battery 
>charger plugged into a variac for a power source.  Put a multimeter with 
>a DC milliamp scale in series with the DC supply.  The anode should be 
>pure silver.  The electrolyte can be mixed from bulk chemicals but the 
>minimum amount available may be impractical.  I got my electrolyte powder 
>premixed from a dental supply company.  You can get your anode the same 
>place.  I would guess that there are jewelry suppliers who would have the 
>same materials.
>
>rhg
>
Thanks for the info Robert.  I've already got my hands on a chunk of
pure silver to use for an anode.  Presumably the piece to be plated
should be used as a cathode.  What isn't clear is what the electrolyte
formulation should be.  I assume there would have to be a silver
compound of some sort in it but which one?  Silver Nitrate, Silver
Chloride, Silver Somethingate ???

I need to know the composition of the premixed powder you referred to so
that I can hunt some down.

Thanks again and sorry for being dense.

Regards

-- 
Marc Line

---

From: Marc Line <[email-masked]>
Date: Tue, 23 Apr 1996 08:45:13 +0100

In article <[email-masked]>, Doug White <[email-masked]>
writes

>I have a small bottle (somewhere) of silver plating powder.  It's a 
>mixture of silver nitrate, table salt, and cream of tartar (I'm not 
>kidding).  The original recipe was in an old Ham radio magazine for 
>silver plating RF components.  You wet a rag, and put some powder on it 
>to make a paste.  Rub vigorously on brass or copper, and it plates out 
>right onto the metal.  I think the cream of tartar is used as the flux to 
>remove any residual oxides.  If no one else comes forward with the 
>proportions soon, I'll see if I can find my bottle and I'll post back.
>
>Doug White

Thanks for your post Doug.

I tried something similar with a commercially available fluid but the
coating was nowhere near uniform enough for my purposes.  I suspect that
the silver content was a little on the low side.

I should appreciate it if you could post details of the proportions of
components in your powder/paste as I'm keen to try anything and
everything to get the results I need.

Thanks again.

Regards.

-- 
Marc Line

---

From: Marc Line <[email-masked]>
Date: Tue, 23 Apr 1996 08:55:34 +0100

In article <[email-masked]>, Gene Olson
<[email-masked]> writes

(in reference to cleaning Roman coins)

>We had several here at one point and the coin poeple said the fastest 
>way to make them totally worthless was to clean off the patina and polish 
>them up/
>
Thanks for the warning Gene.

I know that the removal of patina reduces the saleable value of the
coins to zilch.

My interest is archaeological rather than commercial.  I have directed
the excavation of a Roman villa for some years and many of the coins we
have found are covered with a thick layer of crud as a reult of them
being in close proximity to limestone for almost 2000 years.  We need to
identify and date these as some of them are from vague contexts.  It
seems the only way is to chemically and selectively remove the deposit
so that the glorious detail might be observed.

I have seen photos of before and after when this has been done and if
they are to be believed, it would be worth the trying.  I don't want to
invest in the commercially available gear if our crud is not like their
crud though.

Any ideas?

Regards.

-- 
Marc Line

---

From: [email-masked] (Mark S. Whitlow)
Date: Tue, 23 Apr 1996 13:07:27 GMT

Try Technic in Cranston (sp), Rhode Island.

Good luck

Mark
Helicoflex Company

---

From: [email-masked] (Doug White)
Date: Wed, 24 Apr 96 02:24:14 GMT

In article <[email-masked]>,
   Marc Line <[email-masked]> wrote:
<In article <[email-masked]>, Doug White <[email-masked]>
<writes
<
<>I have a small bottle (somewhere) of silver plating powder.  It's a 
<>mixture of silver nitrate, table salt, and cream of tartar (I'm not 
<>kidding).  The original recipe was in an old Ham radio magazine for 
<>silver plating RF components.  You wet a rag, and put some powder on it 
<>to make a paste.  Rub vigorously on brass or copper, and it plates out 
<>right onto the metal.  I think the cream of tartar is used as the flux 
to 
<>remove any residual oxides.  If no one else comes forward with the 
<>proportions soon, I'll see if I can find my bottle and I'll post back.
<>
<>Doug White
<
<Thanks for your post Doug.
<
<I tried something similar with a commercially available fluid but the
<coating was nowhere near uniform enough for my purposes.  I suspect that
<the silver content was a little on the low side.
<
<I should appreciate it if you could post details of the proportions of
<components in your powder/paste as I'm keen to try anything and
<everything to get the results I need.
<
OK, I remembered that I'd loaned my stuff to a friend, and I called him 
to get the proportions off the bottle:

  1 part-by-weight Silver Nitrate
  2 parts-by-weight table salt
  2 parts-by-weight Cream of Tartar

You just mix them together, and apply as instructed above.  After giving 
it some thought, it may only work on copper and copper alloys.  I've 
never tried to get a particularly heavy plating out of it, but I suspect 
that may be difficult or impossible.  One other problem is that the only 
silver nitrate I could ever find comes in fairly coarse crystals.  For 
best performance, you may want to pulverize and sift the ingredients 
before mixing them.

Enjoy!

Doug White

---

From: [email-masked] (Michael John Hide)
Date: Wed, 24 Apr 1996 04:28:51 GMT

Marc Line <[email-masked]> wrote:

>Hello.

>I hope this is not an inappropriate question for this group.

>I have a need for a simple, cheap (ish) method for plating silver onto
>small items fabricated from copper wire, soldered with tin/lead alloy.

>The operation will have to be "bedroom scale" as space in the workshop
>is at a premium.  

>Does anyone have the answer?  Is anyone doing something like this
>already?  Can you help with it please?

>I wish I'd paid more attention in Chemistry class.

>Which electrode, what voltage, what electrolyte?  You see, I don't know
>where to start.

>Thanks in advance.
The info given using silver nitrate is that used for silver plating
chapter rings of old clocks ,17 and 18 century stuff , long before
todays methods were known .Ithink an amalgum using mercury was used ,
the cream of tarter , if memory serves me was used to  clense the
surface of excess mercury . Any how the result was somewhat fragile
[chapter rings dont get much wear] and is a matt finish unlike modern
plating ,but an attractive soft glow.

---

From: [email-masked] (Don Wilkins)
Date: Wed, 24 Apr 1996 14:50:53 GMT

On Wed, 24 Apr 96 02:24:14 GMT, [email-masked] (Doug White) wrote:

Whole bunch of stuff snipped.
>best performance, you may want to pulverize and sift the ingredients 
This reaction is driven by the reduction of silver ions to the metal
by the copper. You will never build up a thick layer because as soon
as the copper is completely covered with silver there is nothing to
drive the reaction.

You get a similar type of reaction when you dip a knife (iron) blade
into a copper solution. It is called internal electrolysis and is
useful for applying an extremely thin layer.
  _               _   _                  Für d' Flöh gibts a Pulver 
 (_|   |   |_/o  | | | |  o              für d' Schuah gibts a Wix, 
   |   |   |     | | | |      _  _    ,   für'n Durst gibts a Wasser
   |   |   |  |  |/  |/_) |  / |/ |  / \_  bloss fuer d' Dummheit gibts nix.
    \_/ \_/   |_/|__/| \_/|_/  |  |_/ \/

---

From: [email-masked] (Jim Waggener)
Date: Thu, 25 Apr 1996 03:57:28 GMT

Potassium silver cyanide is the common ingredient in the plating
solution. My suggestion would be to just buy a quart of pre-mixed
silver plating solution from one of the jewelry suppliers such as
Swest Inc. or Rio Grande.

Jim Waggener

---

From: [email-masked] (Steve Rayner)
Date: Thu, 25 Apr 1996 04:40:46 GMT

A soak in vinegar or weak sulphuric acid might work.

-- 
************************************************************************
     MY SECRET IS OIL OF HARLEY DAVIDSON !      Steve Rayner
************************************************************************

---

From: [email-masked] (Mick Collins)
Date: Thu, 25 Apr 1996 19:53:14 BST

[email-masked] (Don Wilkins) wrote:

> This reaction is driven by the reduction of silver ions to the metal by
> the copper. You will never build up a thick layer because as soon as the
> copper is completely covered with silver there is nothing to drive the
> reaction.

  Many years ago, when we used to develop and print our own B/W photo's,
spent hypo could be used to deposit silver and much time was spent rubbing
away at old motorcycle headlamp reflectors.  Sadly, it always tarnished
in a few days - and any attempt to clean it simply destroyed it. 
  -- 
     Cheers

  Mick  S.M.E.E.           "From the inventors shop came
                                 the sound of hammering tin"

---

From: [email-masked] (Ole-Hjalmar Kristensen FOU.TD/DELAB)
Date: 25 Apr 1996 08:54:02 GMT

In article <[email-masked]> Marc Line <[email-masked]> writes:

   Any ideas?

   Regards.

   -- 
   Marc Line

Have you considered using an ultrasonic cleaner? It is surprising how
much crud it will remove. I have seen one actually removing painted
letters, using only hot water with Decon-50. Try a friendly physics or
chemistry department to get your hands on an ultrasonic cleaner if you
haven't got one already.It is probably a good idea as a first step
even if you are going to use something else to remove the last
deposits.

A weak acid and plenty of patience should do the trick for removing
limestone deposits. But I'm no chemist, only an ex-physicist turned
computer scientist, so don't take my word for it.

Ole-Hj, Kristensen

---

From: Marc Line <[email-masked]>
Date: Mon, 29 Apr 1996 07:32:56 +0100

Hi all.

It seems that this thread is just about exhausted now so I'd like to say
a big thank you to all those who have offered their valuable advice and
knowledge.

I am impressed by the vivacity of this newsgroup which functions as a
newsgroup should, unlike some of the others to which I subscribe.

Thanks to you all and apologies to those to whom this does not apply.

Best regards

-- 
Marc Line

---

From: Clarence Noyer <[email-masked]>
Date: 30 Apr 1996 06:58:25 GMT

If the crud is lime, vinegar (acetic acid) may be remove it.  Try one of 
the coins so you don't ruin the whole batch.

My wife's stepfather used a system of heating acrylic sheet in a little 
press with coins between the acrylic sheets.  It was a great way to 
produce slides of rare coins.  Some of the slides are probably in the 
Eastman Museum in Rochester NY.

Good luck.   "CC"

---

From: [email-masked] (Dr. Christoph Jung)
Date: 11 May 1996 15:44:54 GMT

-- 
1¾
Re: Roman coin cleaning Q

Dear Marc Line,

I would recommend to you to clean the roman coin from limestone using a 
weakly acidic solution also, but the acid should be specified:

citric acid (its a solid comound to be soluted in tap water), evtl. mixed 
with acetic acid.

The pH-value, which measures the degree of acidity should be not below pH 
= 3 ( a value of 7 corresponds to a neutral, a value of 0 to a very 
strong acidic solution).
Otherwise you may destroy the surface of your coin.

There are some acidic cleaners of this type commercially available in 
supermarkets.
These cleaners you should dilute with tap water 1:50, the diluted 
solution then use in a simple ultrasonic cleaner.

Best regards
                    Christoph Jung