Roman ?

[Chef Geoff]

Sorry I thought you knew that bit, no other coins of that size at that time. You could try Relichunters lemon juice recipe, looking at it though it looks to be calcium build up, so I would suggest Phosphoric acid though

[Meatslicer]

The dog head thingy looks like a stylised pot leg......Maybe

Eric

[ysbytymike]

Sorry I thought you knew that bit, no other coins of that size at that time. You could try Relichunters lemon juice recipe, looking at what looking to be calcium build up I would suggest Phosphoric acid though

Sorry Geoff, didn't know that silver was the only metal at that time for this type of coin.
Phosphric Acid - This the type of thing a chemist stores? been doing a little reading and someone mentioned a
50/50 solution but very few other details. Being only my second ever Roman and a silver to boot, don't want to do anything to degrade the
coin so just trying to get all the relevant info.

Think I've mentioned before some time ago that it would be great to have a database of cleaning techniques for coins and artefacts
including all the temperatures and mixture levels. Perhaps a 'sticky' that could be used for reference?

[Chef Geoff]

If you have a friendly dairy farmer he will have some, and know it as "Milk Stone Remover" but I use it in by way of Swarfega metal cleaner from B&Q.
It won't harm the coin itself though it may fizz when you put it in, this is just the calcium coating, it's not the burning type of acid by the way so don't worry about getting it on your hands though you may be happier wearing rubber gloves.
The whole process will only take approx 2 minutes at most so you can watch it work it's magic.

[Zeus (Joel)]

Spit on it and use the foil method

[ysbytymike]

Already tried that Joel - no effect.
From what I've been told, this build-up is a calcium of sorts, so different from the coating you usually get on hammered that reacts well to spit and silver foil.

[gijan]

WELL DONE SIR ON UR SILVER.......

[relichunting]

The silver paper method will not work for Roman coins with a hard crud on them like this

This is one i found before and after pictures using the olive oil and lemon juice heated in a pan

[ysbytymike]

Cheers relichunter.
What is the actual process and mixture quantities please?
Do you put the liquid into a saucepan and heat to very hot and leave for a while?
Cheers
Ysbyty

[relichunting]

I would not use this method on valuable Roman coins

I find cleaning any coins a very hit or miss affair and there is always a risk your totaly ruin the coin

I use an old sausepan and heat up 1 teaspoon of lemon juice and 4 teaspoons of olive oil

I think if it was my coin i would just leave it soaking in lemon juice for a few weeks taking it out and checking every few days and brushing with a soft tooth brush and returning to the lemon juice untill cleaned  


http://www.colchestertreasurehunting.co.uk/C/cleaning.htm

[Chef Geoff]

I've just noticed on that link that they also mention using vinegar to get rid of calcium. Maybe worth a try first

[imnotginger]

mine when i found it and now after cleaning

[probono]

Hi All

it is of course a denarius, but it is covered (by the looks of it) by Ferrous salts.

In removing deposits from items you need to think about two things;

a) that the reaction of the deposists and the chemical you are using gives you a soluble etch product
b) that the coin underneath + the chemical you are using gives you an insoluble etch product (which then acts as an inhibitor for further etching), or that the etch rate of the coin is much lower than that of the crud.

As ferrous sulphate is soluble in water, you need a sulpher-based acid - the one I would suggest is 'jewellwer's pickling' which is a buffered sulphic acid (sodium hydrogen sulphate) - you can by this from eBay or craft suppliers like Kernowcraft.

After etching the crud, I usually rinse the coins under cold, running water and rub them gently with an old sponge. Sometimes it takes a few goes.

Looking at the reverse legend it seems to end 'COS VII P P' - so will either start TR P..... or SPQR TR P..... Looks like Mars right.

[Tafflaff (Rob)]

Mike, your dogs head looks similar to the one I had and has been Id'd as roman, possibly a handle though the museum was not sure.

[ysbytymike]

Cheers guys. Had it in lemon Juice for a couple of days with regular toothbrush use and its getting there but very slow progress.
Will have a look at this 'jeweller's pickling probono.