Cleaning hammered coins

[Peter99 0]

What is the best method of cleaning hammered coins?

I have a few small hammered coins which I found on the shore at London Bridge

some years age by sight, with nose to the ground.

Since the advent of sophisticated metal detectors I doubt any coins left now.

At the time I did have an early metal detector but which could not discriminate from old iron.

So is was impossible with so much about. Never been back!

Am sure there is an expensive method to clean.

But what would anyone suggest is the best at reasonable cost?

I have done a search on the forum but nothing seems to come up.

Thanks!

[Coinery 926]

You would definitely do no harm with a light wash! If more is needed, you'd do no harm with a couple of weeks' soak in olive oil, and a careful pick/wipe with cocktailstick/cottonbud.

As a general degreaser, junk remover, you could do worse than acetone and cotton bud (pure acetone, not the nail-varnish remover that contains conditioners which leave 'hues' and a 'pretty' smell on the coin).

What kind of 'clean' are we talking? Can you show us some pictures? Would make a massive difference to the approach.

[sound 25]

I would also suggest you read a very interesting post by OZ john a while ago.

Bicarbonate of soda, a little salt and tin foil with near boiling water allow for a controlled removal of deposits without damaging desirable toning. That is if this method is controlled.

Of course your post raises an interesting question, when is cleaning (often considered undesirable) preservation (desirable)? The answer to that invites a wide degree of views.

Regards

Mark

Edited April 28, 2015 by sound

[Peter99 0]

Many thanks for your comments!

Have posted an image of 4. I have about 10 others.

A lot of years ago I identified the four as:-

Top Lt: Edwrad IV penny

Top Rt: Henry VIII Penny of Durham

Bt Lt: Henry VI 1/2penny of Calais

Bt Rt: Charles I rose farthing

I did wash them after finding but over the years in plastic some are not looking too good.

Would appreciate your comments.

[Coinery 926]

I would also suggest you read a very interesting post by OZ john a while ago.

Bicarbonate of soda, a little salt and tin foil with near boiling water allow for a controlled removal of deposits without damaging desirable toning. That is if this method is controlled.

Of course your post raises an interesting question, when is cleaning (often considered undesirable) preservation (desirable)? The answer to that invites a wide degree of views.

Regards

Mark

Mark, have you tried this before? One thing you won't have left is toning! I used to use this method for bulk cleaning necklaces and jewellery. It comes up like new, not necessarily what you'd want from a hammered coin?

But you are absolutely right in questioning whether the method is controlled, and what defines a clean. Some hammered are so knackered that a wire brush would enhance their value, if only to determine the monarch, others would be devalued by the slightest buff.

We could really do with pictures?

[Coinery 926]

Sorry, there ARE pictures!

[Coinery 926]

I'd leave the Rose farthing as-is to be honest.

The problem with heavily encrusted coins like these, is the encrustations have normally exchanged particles, atoms, somethingons, call them what you will, with the surface silver of the coin, so removing these surfaces normally leaves you with a pin-holey, wire-wormed, nasty piece of silver with slushy detail.

As an experiment once, I dissolved a corroded C2 farthing, just to see how far I'd have to go to find copper. It turned out the copper had long since turned into a brittle reddish material. I've no idea what it was, but it's a lesson to demonstrate you may not find the original coin beneath the mess.

I'd say for the coins you've posted that it's best to stick with a pick and a soak...there's not an unblemished flan lurking beneath.

[JPK 3]

Spit on a coin ( silver one ) and gentle rub with tin foil,( shiny side )then clean off with a soft cloth,won't work on the heavy encrusted,but will shine up the blacker ones,obviously don't do this on any that are valuable.

Btw there's plenty more in the Thames still,check out Thames&field website.

[sound 25]

Coinery,

As a rule we don't clean coins, however I did try OZ John's suggestion on an old worn coin.

The point is that by leaving it for just a few moments it didn't lift all of the toning. In his example he was able to improve the coin without stripping all of the toning.

Mark

[TomGoodheart 373]

Personally I've seen horrible coins on which the seller has claimed to have used the foil and spit technique. "Just a gentle clean".

My preference is therefore, unless you are keeping the coin, in which case drill a hole through it for all I care, leave it alone and let the buyer bugger it up improve it if they wish ...

.

[Peter99 0]

Many Thanks for all your comments!

I feel I must do something to stop what might be going on now.

I think as Coinery has suggested, I will leave them in soak for a couple of weeks and do a bit of gentle picking and see how I get on.

As JPK suggests, am sure there is still plenty about, down there/up there, but with a little digging no doubt!

The best pitch if anyone wants to try, at least in my experience, is between London Bridge & Queenhithe dock. I should go for it!

I know that people have found the odd sov, but I think one of the finds best must be a medieval kidney dagger found in mint condition

in the mud.

A really vicious looking weapon, The blade about 1" wide under the kidney shaped hilt and running triangular shaped

about 12/15" to a fine point.

The nastiest bladed weapon I've ever seen, now in The Museum of London.

One can only guess why a triangular shaped blade!

[TomGoodheart 373]

One can only guess why a triangular shaped blade!

It causes an injury that bleeds internally but the skin closes over it. Hit the right spot (kidneys) and fatal through blood loss but little external trace.

.

[Coinery 926]

Coinery,

As a rule we don't clean coins, however I did try OZ John's suggestion on an old worn coin.

The point is that by leaving it for just a few moments it didn't lift all of the toning. In his example he was able to improve the coin without stripping all of the toning.

Mark

I'd personally leave that technique well alone to be honest!

[sound 25]

Coinery,

As a rule we don't clean coins, however I did try OZ John's suggestion on an old worn coin.

The point is that by leaving it for just a few moments it didn't lift all of the toning. In his example he was able to improve the coin without stripping all of the toning.

Mark

I'd personally leave that technique well alone to be honest!

Well like most I agree that cleaning is best left alone. Does come back to my point, when is cleaning, preservation rather than just cleaning?

With OzJohn's example, granted not a hammered coin, it was a definite improvement.

Mark