coin cleaning

[duggee27]

hi all,
am a bit of a stalker here and elsewhere to learn about coins being my new hobby. this site is more informative and aussie.
but whilst channel surfing came across a yank show called 'dirty jobs'. mike , the host, had to clean coins for a hotel in san francisco , a job they have been doing for 80 years.
in a metal tumbler were BB pellets, borax , water and coins for 2 hours. then rinsed, shaken dry ,then under a heat lamp. presto super clean shiny coins !!

feel sorry for U.S coin collectors and hopefully this does not happen here

[Bigfellani5]

Very bad. If you have the urge seek a professionals advice first. The general rule is remove grease and dirt but nothing else.

[Australian coin]

:welcome:

haha I remember Mike Rowe [Dirty Jobs] I like that show

people in Oz don't clean circulation coinage as far as I know. so we should be ok, but it sounds pretty weird

[Mister T]

I saw that on TV recently (only the end) but I didn't realise it was for a hotel. The BBs really crosses the line.

[enworb]

Ive seen that as well. Its interesting that they do that. I wouldnt have thought the benefits of passing out clean coins would outweigh the cost of employing someone to clean them.

[stevo1962]

An interesting custom but a good way to devalue collectable coins

[WavyTwenty]

Cleaning coins is usually a no-no.  However, I have seen that sometimes when a coin is professionally cleaned it will sell for more than if it was not cleaned.

I think eventually coins that are not cleaned will get to be rarer and rarer.  Although, professionally cleaned coins can be very difficult to tell from natural high quality coins.

Wavy20

[Goldseeker]

I have just done what one is not supposed to do and that is clean a few coins.   The four coins were all metal detected by me over the years and the year of the coins is 1926.   I have put up the before and after scans below for comment.

I used a liquid called TARN OFF, available from Bunnings.   I put the coins in the liquid, leave for a few moments, remove and lightly rub/clean with a cotton bud.   Then placed in water for soaking and then dried on a cloth and placed into a warm oven for final drying.

This set will be placed onto Ebay for a Birthday Coin set shortly.

Now question is do I do it for my used pre decimal collection or not?

The results were amazing.   See for yourselves:

[Fulvio]

I used a liquid called TARN OFF

Eeeeeeeeeeeekkkkkk!!!

They're RUINED!!!

Seriously, see how flat they are after cleaning? Not a good look.

That said, I'm cleaning what was a 1999 UNC $1 which I found covered in crud, possibly from PVC. So far its resisted Acetone, Soap and now RP7. Next it will get another hot soapy bath, then more acetone, then if all else fails I might consider a little manual assistance, but I'd never use Tarn Off, cos it would completely ruin it.

but whilst channel surfing came across a yank show called 'dirty jobs'. mike , the host, had to clean coins for a hotel in san francisco , a job they have been doing for 80 years.

I remembered seeing this show, and just had to dig it out and watch it again just now.

Dirty.Jobs.S09E04.Water.Softener.Technician.avi
From January 2012

Steel BB's (which he picks up with a magnet when he drops a heap) and Borax, tumbling for two hours. Dem dar quarters shore is SHINY, Boss! And if that's not enough damage, I hate to think what the ancient rolling machine did to them as well. *SHUDDER*

On the other hand, he digs out a big lump of goop with his finger, and points out that they remove two gallons a week of solid gunk. At least it won't be infecting any of their customers with all sorts of horribleness, eh?

But its still a terrible thing for a collector to watch...

[robbiegal]

I guess that is the origins of the term 'money laundering' ha ha

They do a similar thing to coin planchets at the Mints!

from the RAM website

During the preparation of the blanks the action of the rolling and rimming operations creates a change in the condition of the metal. This effect is called Work Hardening. The blanks need to be softened slightly before they can be struck with the die. This softening process is carried out in a furnace by heating the blanks to around 850 degrees Celsius and then cooling them again. After annealing, the blanks are then transferred to a burnishing unit.

Burnishing

Burnishing is used to make the surface of the blanks brighter, remove any discolouration and in some cases apply a minute amount of lubricant to assist in coining. This is carried out in a Burnishing Machine that tumbles the blanks amongst a mixture of small steel balls and ceramic media combined with special chemicals, which etch and polish the surface. After burnishing, the blanks pass through a hot air drier. The annealed, burnished and dried blanks are stored ready for coining.

[JeffH]

I am sure Tarn Off is the same as Tarn-X. Perhaps Jeffrey has his own agenda but his site is worth a look. Destructive & Dangerous Tarn-X

Jeff (Devil's advocate)

[Goldseeker]

Thanks for that Jeff.   Message received and understood.

[Fulvio]

I answered these questions in a PM just now, then thought they might interest a wider audience. I didn't go into huge detail, but would recommend people read the Wiki page:

http://en.wikipedia.org/wiki/Acetone

Particularly the Safety section, as regards Flammability, Toxicology and Environmental effects.

Also, when cleaning coins, do not rub, even with cotton wool. Dip a cotton bud in Acetone (I use wooden rather than plastic, and re-roll them when they get dirty) and ROLL it across the coin. Or dab with cotton balls, but never ever rub.

This acetone liquid.   In discussions on the forum it is supposed to be good for cleaning coins.   What's your idea on this?

Its an organic solvent, which is produced in your body actually. It will dissolve all manner of organic gunk, and is safe for metals and SOME plastics (not polystyrene. It dissolves that like water dissolves sugar).

Further,   is the acetone dangerous to handle, what is the cost and any special containers needed to use it?

Depends on who you ask. A lot of countries listed it as hazardous, and most have since taken it off the list. It was the primary component of nail polish remover, and is used to strip paint. It does dissolve fats, so will strip the oils from your skin (which may be good or bad). Its not particularly dangerous to breathe in, but may give some people headaches or similar. Like with any household cleaner, use common sense. Don't bathe in it, use rubber gloves if you're going to use large quantities, and good ventilation is best.

A chemist will charge you $10-12 for a 100ml bottle, which is outrageous. Bunnings will charge you a tenth of that, which is still ten times the bulk price. They sell 1L HDPE bottles and 4L tin cans. I bought the big one for $38, and will refill the 100ml bottles from it.

It will not affect Polyethylene. So the LDPE bank bags (I strip the printing off them with it) and HDPE milk bottles are safe from it. I put coins in the bags, add acetone and seal them in a wide-mouth glass jar in case of leakage. I was going to transfer from the tin to a milk bottle, but might look for a smaller HDPE container instead, or go back to Bunnings and buy a 1L bottle instead, just because the tin is awkward to handle.

Also note this stuff is extremely volatile. And flammable. So don't leave the lid off or you will have an empty container. And don't use it near flames or there might be an earth-shattering KA-BOOM!

Like any chemical, respect is paramount.

[ausjack]

I thought that givin it a good hard rub was standard ebay practice so was thinkin about adopting the idea myself :mocking:

[Fulvio]

I thought that givin it a good hard rub was standard ebay practice so was thinkin about adopting the idea myself :mocking:

Nah, they use the buffer and cutting compound. :dodgy: