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#1

Wolfau
Guest
Guest
16 August 2014 09:53 pm

This is something i have never done in all my time
Metal detecting. Does anyone have a good method
Of cleaning coins found without damaging them?

Your help would be appreciatted.

Thank You

#2

Zuke_Lynzy
Guest
Guest
16 August 2014 11:33 pm

Wolf iv got a soft small wire brush I just gently scrub in my hand, otherwise you have to get serious and it could damage the coin.
#Lemon & salt scrub for copper.
#Bicarbonate soda for gold & silver.
Or Karl uses Aquarium gravel in a tumbler I think with a little wash liquid.
Iv also made a small electrolysis treatment system but it usually marks the coins.
You could make a small tumbler that you could rotate with a cordless drill while watching TV.

1 user likes this post: Wolfau

#3

Nugget
Member
Joined: 27 November 2012
Posts: 6,041
Member
16 August 2014 11:47 pm

I posted this on another topic recently.

Nugget wrote:

Check out this topic for cleaning Silvers https://www.prospectingaustralia.com.au … php?id=663, and this one for old encrusted coins https://www.prospectingaustralia.com.au … hp?id=4101

I generally don't bother cleaning Coppers, however some have had luck soaking them in Olive Oil for several weeks to months then using a soft brush / sponge to clean away any dirt etc, while others have used electrolysis.

CLR and the like should be avoided as in my experience it does much more damage than good.

1 user likes this post: Wolfau

#4

Westaus
Member
Joined: 09 March 2014
Posts: 489
Member
17 August 2014 12:55 am

No #1 rule always check first you do not have a valuable coin. If you do, DO NOT CLEAN IT.

If it is not valuable doesn't matter then.. Use different methods for different materials as mentioned.

Soft and slow is better than fast and abrasive. Be it friction or chemical. So slow and steady.

Got to find the coins now. Best of luck.

1 user likes this post: Wolfau

#5

Decado
Member
Joined: 25 September 2013
Posts: 44
Member
17 August 2014 04:15 am

Hi WolfAU

I'm going to cut and paste from a much older post in a minute but as a rule of thumb before I do

Anything that is abrasive leaves marks that can be seen under magnification, this devalues the finds.

For coppers and Brass a tumbler or a good soak in olive oil works as well as anythign else. I do NOT suggest electrolysis for those materials as it leads to something called "dezincification" and leaves that horrible pitted pinky look no one likes.

You can try the molassis fermentation method which sometimes leads to results nothing short of amazing

If you have a silver that is in pretty nice condition to start with you should been no more than the bi-carb and alfoil method to get a really good result.

If you have an iron object or an object that has been resting against something iron in the ground the Electrolysis is your best bet.

Example here is a USMC EGA HAt badge my daughter rescued from the scrap pile of another detectorist last week, it had been resting against iron and until some of the concretion had been scraped away looked like nothing more thana block of rust.

After scraping enough to be sure it was something it looked liked so

1408209162_a.jpg

After 10 hours slow electrolysis is looked like so

1408209199_b.jpg

Also silver that has been through a fire or rested for years against a dis similar metal can become stained and in these cases Electrolysis is a viable solution.

Below is a "how to" I put together a year or so ago for another forum where I am a member and has been re preinted here before also.

---------------------------------------------------------------------------------------

OK, firstly I'm going to assume you wish to do smaller items like coins, buckles and the like rather than larger items like machinery parts or artillary shells ( =-| )although the process is similar the power supply requirements become greater and more dangerous to the user and are there for outside the scope of this post.

Electrolytic cleaning 101

First off you must ask the question "Do I really wish to clean my artifacts this way?" There are other albeit slower methods that work equally well for some materials and are more environmentally friendly and also without risk to yourself and your item. As the process involves essentially a reverse electroplating action where surface layers a few microns thick are removed instead of added this would not be the method to clean a pristine and unique coin ready for sale for example .. although why you'd clean a pristine anything I am not quite sure? For cleaning something removed from the ground or the sea that needs to be identified, have markings revealed or cleaned up for your own personal collection then electrolysis is a viable and effective solution.

Some people will have you believe "I electrolysised my coin and it ate it away" this is generally untrue except at extreme high current levels. Alloys are an exception and will erode quite quickly. That's not to say they should never be electrolysised, they should just be carefully attended and checked very frequently to avoid pitting.

Electrolysis removes oxidation of all kinds well before it damages the host metal to any discernable degree unless you were to forget and leave it there for a day or two .... by which time with a plug pack powered system you'd be too busy putting out the fire to worry about the item.

Electrolysis removes all oxidisation, what collectors call "patina" is in fact oxidisation. Removing it can devalue your item, copper coins end up bright and shiny for example although they do re acquire their usual dull finish quite quickly minus the horrible green corrosion. If all that is holding your item together is the patina however then it's not going to end well.

You're going to see a lot of conflicting information about this on forums and on the web regarding electrolysis as a cleaning method, a lot of what is suggested works well but is unwise due to safety concerns and/or because it can damage your item. I've gotten to the point on forums where I just don't bother repeating myself any more because two posts later someone is saying "oh doing it such and such a way works fine for me" >_<.

I'm no guru but I am a technician by trade and did run an industrial chrome plating plant for a time so I have half a clue at least.

So, the other cleaning methods being outside the scope of this "how to" and taking as read you have decided electrolysis is the path you wish to follow then read on.

Materials and Equipment

Bath:-
--------

Start with a small non conductive container either plastic, Pyrex or glass, keep in mind that the process can involve temperatures up to 900º f at the point of which the alligator clips touch the item being cleaned so if using plastic do not allow the item or clip to touch the side of the container.

Electrolyte:-
---------------

Into your container pour plain tap water, distilled or otherwise has no benefit. Add Washing Soda (Sodium Carbonate) at a ratio of around 2 tea spoons per liter of water and mix it in thouroughly, "Arm and Hammer" and "Lectric" are two brands of washing soda that spring to mind. You'll find them with washing powder at the supermarket. You now have your electrolyte.

While most people use table salt in the water I do not support this as it gives off chlorine gas while the process is underway. Baking Soda (Sodium Bicarbonate) also works and while safe as far as chlorine gas goes does release salts that can corrode your item.

Regardless of what you use the process gives off Hydrogen gas so no smoking or naked flames and do it in a well ventilated area.

While electrolyte solution has no definitive life and can be used until it is black with a scum on the surface you should ALWAYS use a new solution when changing the material being cleaned. If you have brass and silver items, do one type and then change the solution and do the other. Failure to do so can result in plating due to the metals in solution and your silver may end up coppery in colour and vice versa.

Power supply:-
-------------------

Many people use a battery or battery charger, for smaller items this is huge over kill and adds danger to boot. For small items when you can monitor the process a plug pack works fine. Voltage is not critical with the upper limit being 24v for safety reasons, 9 to 12v being ideal. Ideally you want to pass about 300ma of current through a coin sized item being cleaned. I like to use a supply capable of 1 amp so as to not work it too hard. Something like a laboratory supply such as this one :-

http://www.jaycar.com.au/productView.asp?ID=MP3086

Would be a "Rolls Royce" solution allowing you to pre set the voltage and current there by avoiding the current limitation issues I will address shorty and allowing you to leave the process un attended safely for periods. I intend to purchase one myself but for most people it will be overkill so I'll continue as if you are using a plug pack.

Bare the wires and attach alligator clips to the ends of the wires being sure to mark positive and negative.

Confirm these with a multi meter if needed. Some people tell you that you can tell them apart as the negative lead will bubble in the solution, while this is true to some degree in a perfectly balanced setup BOTH ends bubble so don't risk it and check with a multi meter. If you get it the wrong way around you can errode or plate your item with metal from the anode.

The current is the critical issue here and sadly to say for the average hobbyist it is not really simple to regulate.

a) You could mix your electrolyte to a specific resistance by varying the ratio of washing soda to water but this is not easy to measure without specialised equipment.

b) You could use a regulated supply as shown above but this is expensive,

c) You could place a large 10watt wire wound resistor in line to limit the maximum delivered current to 300ma. Nominal values would be 40 Ohms for a 12v supply, 30 Ohm for a 9v supply or 20 Ohms for a 6v supply.

That said, plug packs vary greatly in voltage output both when under load and not under load so this is not a magic bullet. Also while the plug pack may not get too hot using this method the resistor will and so monitoring it is still required.

d) You can vary the distance between the item and the anode to achieve the desired resistance but again this is hard to measure for the hobbyist due to the equipment required.

e) What most people will do is just mix the electrolyte at the ratio specified, connect the plug pack in the correct polarity and monitor the process by way of placing your hand on the supply. Using a quality 1amp supply will not introduce enough current to damage an item and should be able to operate 15 or 20 minutes before becoming too hot to leave your hand on at which point it should be unplugged. That said .. DO NOT TAKE THIS FOR GRANTED!!! Unless using a regulated and cooled laboratory supply never leave the process un attended.

Also, it pays big dividend to use a small brushless fan to cool the supply or the resistors if you use that method. You can scrounge one from old electronics or buy one from a hobby store. If you choose carefully you will be able to power it from the same supply remembering to allow for the current load it will add. For your first experiments the fan will not be a must have item but for longevity of your set up it's a good idea.

Anode materials :-
------------------

The most common material used for your anode (which will have the positive lead attached) by home electrolytic cleaners is a stainless steel spoon. I can not stress this enough. Just don't use any stainless steel item as your sacrificial anode. If you do the process will result in Hexavalent Chromium being released into the electrolyte. See here :- http://www.workplace-hygiene.com/articl … pdate.html

Further, the resulting electrolyte becomes illegal to dispose of down the drain and must be allowed to evaporate and then the residue must be disposed of a a toxic waste facility.

I don't care what "Fred F***wit" from the "International metal detecting, asbestos munching and growing an extra head forums says" just DON'T mmmm k?

Likewise, don't use zinc plated metals for similar reasons.

Aluminium works although it results in a slower process (sometimes a good thing) but by far and away the best is plain old untreated mild steel available as offcuts at a metal work shop near you.

The anode will over time be eaten away and become covered in rust and impurities, it will require periodic scrubbing and will need to be replaced now and again. You can also clean it by connecting another sacrificial plate and reversing the polarity but this is a little counter intuitive to me as it requires higher current levels and if you're going to use another sacrificial plate you might as well replace the original.

Technique

a) Take your bath and mix the electrolyte as outlined above.

b) Place the sacrificial anode on one side of the bath. Ideally it will not be totally submerged. Clip the positive lead from your supply to the anode out of the water.

c) Take the item to be cleaned and make sure an area is clean enough to make electrical contact, You can gently rub a tiny out of the way area with 0000 steel wool if needed. Clip the negative lead to this place.

d) Submerge the item to be cleaned on the opposite side of the container to the anode, clamp it in place totally submerged with as little of the alligator clip on the negative lead in the water as possible.

e) Plug in the power supply.

At this point the item and probably the anode will start to bubble, the cleaning process has begun. How long it will take depends on the material being cleaned and the current passing through it. Thin alloy such as identification tags should be removed every minute or two and gently brushed and inspected and then replaced if more is required. Coins and buttons will generally require 5 to 10 minutes and larger items such as buckles may take half an hour or more.

As the item cleans it will become black from the process. This is nothing more than carbon. Once all the corrosion and other undesirable material has been dissolved place it in the palm of your hand over a sink and cover it with Sodium Bicarbonate. Add a dob of toothpaste and a few drops of water and mix into a smooth paste. Using a toothbrush firmly but gently brush the entire object with the paste removing all the carbon. At this point you can decide if your item needs to go back in the bath for another treatment.

Considerations

a) Electrolysis is a "line of sight" process. The area of the item being cleaned facing the anode will clean most effectively. You can either turn the item several times during the process or arrange your bath so that there is a sacrificial anode on each side of the bath and your item hangs in the middle.

b) At no time while in the bath should the postively charged anode be allowed to come into contact with the negatively charged item being cleaned. Should this take place while power is applied you will at the least blow your plug pack and potentially trip your home circuit breakers and start a fire. Some people place a plastic mesh in the middle of the bath but this can cause shadows on the item being cleaned due to "line of sight" effect. Simplest solution is just take great care.

c) While highly unlikely 300ma is many times the current required to disrupt and potentially stop the human heart under "perfect storm" conditions. You'd be more likely to win lotto than to die using < 24v and 300ma but still ALWAYS unplug the supply before inspecting, turning, brushing or touching the item in any way

You have been warned.

While every care has been made in preparation of these instructions and this process is undertaken safely by many thousands of people each year I accept NO responsibility for injury or negative results through failure to follow these instructions, unforeseen circumstances and the electrolytic cleaning process in general.

I may edit this guide at times as new techniques and information comes to hand and of course to correct the ever present spelling and grammar errors big_smile

Hope this helps

Regards
Dec


Currently using:- Minelabs X-Terra 705 Dual Pack, Minelabs Sovereign GT, Minelabs Explorer SE Pro

4 users like this post: Mackka, Monty, Wolfau, AngerManagement

#6

Piston_Broke
Member
Joined: 15 August 2014
Posts: 69
Member
17 August 2014 12:24 pm

Hi,
Has anyone tried using a micro blaster to clean the muck off the surface of a coin ???

Yesterday I found my 1st coin (yay !)....a 1977 Aussie 1 cent piece. Found in my own backyard not long after assembling my unit & giving it a test out.

Being as how its not a valuable coin I thought I'll give the micro blaster a go & maybe take some before/after pics to compare ?
I'm thinking of taping 1/2 the coin up then blasting the exposed half under low pressure (say 2 bar on the compressor ?) using a non abrasive like 250 micron spherical glass beads....then ripping off the tape to show the difference.

1 user likes this post: Wolfau

#7

Paulmarr
Member
From: Adelaide, SA
Joined: 05 November 2013
Posts: 866
Member
17 August 2014 02:12 pm

Piston_Broke wrote:

Hi,
Has anyone tried using a micro blaster to clean the muck off the surface of a coin ???

Yesterday I found my 1st coin (yay !)....a 1977 Aussie 1 cent piece. Found in my own backyard not long after assembling my unit & giving it a test out.

Being as how its not a valuable coin I thought I'll give the micro blaster a go & maybe take some before/after pics to compare ?
I'm thinking of taping 1/2 the coin up then blasting the exposed half under low pressure (say 2 bar on the compressor ?) using a non abrasive like 250 micron spherical glass beads....then ripping off the tape to show the difference.

I have blasting cabinet and glass bead and tried the above - it removes detail from the coin and the metal looks brand new which makes the coin look cleaned and fake ... Ok if you just want to see the date but renders the coin worthless except for scrap value.


Team Bogan member - GOLD BABY!

2 users like this post: Wolfau, AngerManagement

#8

slipped disc
Member
Joined: 14 May 2014
Posts: 553
Member
17 August 2014 02:49 pm

Cheers DEC. big post, very detailed. much more complex than I have read. I use salt and vinegar for a quick clean of
ordinary, coins. swirl the mixture and coin around a bit and check even 10/15 mins. can be aggressive depending on how much salt used. vinegar alone is slower. check coin and dates for value if unsure. if valuable, the accepted guide is not to clean them,seek a reputable coin dealer for advice etc. smile


AHAAA,another 6 inch deep pulltab. Yippee, a 12 inch deep pulltab - SOV.XS.

#9

Piston_Broke
Member
Joined: 15 August 2014
Posts: 69
Member
17 August 2014 03:36 pm

Paulmarr wrote:
Piston_Broke wrote:

Hi,
Has anyone tried using a micro blaster to clean the muck off the surface of a coin ???

Yesterday I found my 1st coin (yay !)....a 1977 Aussie 1 cent piece. Found in my own backyard not long after assembling my unit & giving it a test out.

Being as how its not a valuable coin I thought I'll give the micro blaster a go & maybe take some before/after pics to compare ?
I'm thinking of taping 1/2 the coin up then blasting the exposed half under low pressure (say 2 bar on the compressor ?) using a non abrasive like 250 micron spherical glass beads....then ripping off the tape to show the difference.

I have blasting cabinet and glass bead and tried the above - it removes detail from the coin and the metal looks brand new which makes the coin look cleaned and fake ... Ok if you just want to see the date but renders the coin worthless except for scrap value.

Thank you for your response,

I totally agree that low pressure blasting with glass beads would
leave a surface shiny & looking rather brand new

I'm not so sure it would remove actual detail though under low pressure ?

I regularly use this method to devest gold & precious metal castings from their investment moulds & never see any damage under the 30x magnification that I work under.

But admittedly I've yet to use this on a coin !
Thanks again,
Cheers.

#10

Decado
Member
Joined: 25 September 2013
Posts: 44
Member
17 August 2014 05:12 pm

slipped disc wrote:

Cheers DEC. big post, very detailed. much more complex than I have read. I use salt and vinegar for a quick clean of
ordinary, coins. swirl the mixture and coin around a bit and check even 10/15 mins. can be aggressive depending on how much salt used. vinegar alone is slower. check coin and dates for value if unsure. if valuable, the accepted guide is not to clean them,seek a reputable coin dealer for advice etc. smile

Cheers Slipped Disc and you're welcome for any help it gives

I'll admit to a little outside experience here from the fact that until he retired a few years back my Father was a premier coin and stamp and militaria dealer in Aus with a large ebay store etc etc and I have undertaken a few high value restorations for him and other collectors now and again.

I would like to stress we're talking about coins of key dates or rare artifacts that had sat in salt water or similar harsh conditions for a long time and so there was little to lose in the attempt.

Anyone who takes an item in good condition to start with and tries to improve via electrolysis is heading for tears but as you can see from the USMC badge .. if it's stuffed anyway you can be surprised by the result. Also I always go for a "sypathetic" restoration leaving as much patina in place and avoiding the "bright and new" look.

The bottom line it ... there is NO "one size fits all" solution.

Regards
Dec

P.S. I LOVE silver items, they are next to impossible to ruin and electrolysis is the one sure method to remove staining from fires and laying against dis similar metals for many years.

Last edited by Decado (17 August 2014 05:18 pm)


Currently using:- Minelabs X-Terra 705 Dual Pack, Minelabs Sovereign GT, Minelabs Explorer SE Pro

1 user likes this post: AngerManagement

#11

KarlS
Member
From: Blacktown, NSW
Joined: 14 February 2014
Posts: 679
Member
17 August 2014 05:46 pm

I use tumbler and aquarium gravel with dash of Jiff. That is for current coins only. It is easy, you can do $30 or more in one go. And the banks accept cleaned coins without problems. Before I started cleaning coins I deposited over $100 just washed coins in the bank and had to wait about three months before it was credited to my account.
Karl


White's SPP, XTERRA 705, old Tandy detector

1 user likes this post: Wolfau

#12

Wolfau
Guest
Guest
17 August 2014 11:51 pm

Thanks for your time and replies.

Its greatly appreciated.

#13

Ben78
Member
Joined: 18 February 2013
Posts: 913
Member
18 August 2014 09:26 am

Silver - spit in alfoil, wrap the coin up and listen to it sizzle. After 30sec open it up and buff with bicarb.

Copper - throw it in a tin, ai'nt nobody got time for that!


Digging for gold in the Peel Fault. Currently using Gold Bug SE and all sorts of other paraphernalia!

1 user likes this post: Wolfau

#14

Nugget
Member
Joined: 27 November 2012
Posts: 6,041
Member
18 August 2014 10:05 am

Ben78 wrote:

Silver - spit in alfoil, wrap the coin up and listen to it sizzle. After 30sec open it up and buff with bicarb.

Really Ben, really? lol

Ben78 wrote:

Copper - throw it in a tin, ai'nt nobody got time for that!

+1

1 user likes this post: AngerManagement

#15

Wolfau
Guest
Guest
18 August 2014 10:20 am

Ben78 wrote:

Silver - spit in alfoil, wrap the coin up and listen to it sizzle. After 30sec open it up and buff with bicarb.

Copper - throw it in a tin, ai'nt nobody got time for that!

2c coins missing sd can be worth something..

http://blog.perthmint.com.au/2012/07/20 … ollectors/

#16

Ben78
Member
Joined: 18 February 2013
Posts: 913
Member
18 August 2014 11:10 am

Nugget wrote:
Ben78 wrote:

Silver - spit in alfoil, wrap the coin up and listen to it sizzle. After 30sec open it up and buff with bicarb.

Really Ben, really? lol

Try it man, it doesn't disappoint!


Digging for gold in the Peel Fault. Currently using Gold Bug SE and all sorts of other paraphernalia!

#17

Ben78
Member
Joined: 18 February 2013
Posts: 913
Member
18 August 2014 11:10 am

Wolfau wrote:
Ben78 wrote:

Silver - spit in alfoil, wrap the coin up and listen to it sizzle. After 30sec open it up and buff with bicarb.

Copper - throw it in a tin, ai'nt nobody got time for that!

2c coins missing sd can be worth something..

http://blog.perthmint.com.au/2012/07/20 … ollectors/

Maybe, but its rare to dig a copper coin that is even remotely good enough condition to be worth much - not when you can buy coins that have sat in a tin in nans dresser for 30 years...


Digging for gold in the Peel Fault. Currently using Gold Bug SE and all sorts of other paraphernalia!

#18

Monty
Member
From: Perth, WA
Joined: 01 January 2014
Posts: 127
Member
19 August 2014 09:07 am

Decado wrote:

Hi WolfAU

I'm going to cut and paste from a much older post in a minute but as a rule of thumb before I do

Anything that is abrasive leaves marks that can be seen under magnification, this devalues the finds.

For coppers and Brass a tumbler or a good soak in olive oil works as well as anythign else. I do NOT suggest electrolysis for those materials as it leads to something called "dezincification" and leaves that horrible pitted pinky look no one likes.

You can try the molassis fermentation method which sometimes leads to results nothing short of amazing

If you have a silver that is in pretty nice condition to start with you should been no more than the bi-carb and alfoil method to get a really good result.

If you have an iron object or an object that has been resting against something iron in the ground the Electrolysis is your best bet.

Example here is a USMC EGA HAt badge my daughter rescued from the scrap pile of another detectorist last week, it had been resting against iron and until some of the concretion had been scraped away looked like nothing more thana block of rust.

After scraping enough to be sure it was something it looked liked so

https://www.prospectingaustralia.com.au … 9162_a.jpg

After 10 hours slow electrolysis is looked like so

https://www.prospectingaustralia.com.au … 9199_b.jpg

Also silver that has been through a fire or rested for years against a dis similar metal can become stained and in these cases Electrolysis is a viable solution.

Below is a "how to" I put together a year or so ago for another forum where I am a member and has been re preinted here before also.

---------------------------------------------------------------------------------------

OK, firstly I'm going to assume you wish to do smaller items like coins, buckles and the like rather than larger items like machinery parts or artillary shells ( =-| )although the process is similar the power supply requirements become greater and more dangerous to the user and are there for outside the scope of this post.

Electrolytic cleaning 101

First off you must ask the question "Do I really wish to clean my artifacts this way?" There are other albeit slower methods that work equally well for some materials and are more environmentally friendly and also without risk to yourself and your item. As the process involves essentially a reverse electroplating action where surface layers a few microns thick are removed instead of added this would not be the method to clean a pristine and unique coin ready for sale for example .. although why you'd clean a pristine anything I am not quite sure? For cleaning something removed from the ground or the sea that needs to be identified, have markings revealed or cleaned up for your own personal collection then electrolysis is a viable and effective solution.

Some people will have you believe "I electrolysised my coin and it ate it away" this is generally untrue except at extreme high current levels. Alloys are an exception and will erode quite quickly. That's not to say they should never be electrolysised, they should just be carefully attended and checked very frequently to avoid pitting.

Electrolysis removes oxidation of all kinds well before it damages the host metal to any discernable degree unless you were to forget and leave it there for a day or two .... by which time with a plug pack powered system you'd be too busy putting out the fire to worry about the item.

Electrolysis removes all oxidisation, what collectors call "patina" is in fact oxidisation. Removing it can devalue your item, copper coins end up bright and shiny for example although they do re acquire their usual dull finish quite quickly minus the horrible green corrosion. If all that is holding your item together is the patina however then it's not going to end well.

You're going to see a lot of conflicting information about this on forums and on the web regarding electrolysis as a cleaning method, a lot of what is suggested works well but is unwise due to safety concerns and/or because it can damage your item. I've gotten to the point on forums where I just don't bother repeating myself any more because two posts later someone is saying "oh doing it such and such a way works fine for me" >_<.

I'm no guru but I am a technician by trade and did run an industrial chrome plating plant for a time so I have half a clue at least.

So, the other cleaning methods being outside the scope of this "how to" and taking as read you have decided electrolysis is the path you wish to follow then read on.

Materials and Equipment

Bath:-
--------

Start with a small non conductive container either plastic, Pyrex or glass, keep in mind that the process can involve temperatures up to 900º f at the point of which the alligator clips touch the item being cleaned so if using plastic do not allow the item or clip to touch the side of the container.

Electrolyte:-
---------------

Into your container pour plain tap water, distilled or otherwise has no benefit. Add Washing Soda (Sodium Carbonate) at a ratio of around 2 tea spoons per liter of water and mix it in thouroughly, "Arm and Hammer" and "Lectric" are two brands of washing soda that spring to mind. You'll find them with washing powder at the supermarket. You now have your electrolyte.

While most people use table salt in the water I do not support this as it gives off chlorine gas while the process is underway. Baking Soda (Sodium Bicarbonate) also works and while safe as far as chlorine gas goes does release salts that can corrode your item.

Regardless of what you use the process gives off Hydrogen gas so no smoking or naked flames and do it in a well ventilated area.

While electrolyte solution has no definitive life and can be used until it is black with a scum on the surface you should ALWAYS use a new solution when changing the material being cleaned. If you have brass and silver items, do one type and then change the solution and do the other. Failure to do so can result in plating due to the metals in solution and your silver may end up coppery in colour and vice versa.

Power supply:-
-------------------

Many people use a battery or battery charger, for smaller items this is huge over kill and adds danger to boot. For small items when you can monitor the process a plug pack works fine. Voltage is not critical with the upper limit being 24v for safety reasons, 9 to 12v being ideal. Ideally you want to pass about 300ma of current through a coin sized item being cleaned. I like to use a supply capable of 1 amp so as to not work it too hard. Something like a laboratory supply such as this one :-

http://www.jaycar.com.au/productView.asp?ID=MP3086

Would be a "Rolls Royce" solution allowing you to pre set the voltage and current there by avoiding the current limitation issues I will address shorty and allowing you to leave the process un attended safely for periods. I intend to purchase one myself but for most people it will be overkill so I'll continue as if you are using a plug pack.

Bare the wires and attach alligator clips to the ends of the wires being sure to mark positive and negative.

Confirm these with a multi meter if needed. Some people tell you that you can tell them apart as the negative lead will bubble in the solution, while this is true to some degree in a perfectly balanced setup BOTH ends bubble so don't risk it and check with a multi meter. If you get it the wrong way around you can errode or plate your item with metal from the anode.

The current is the critical issue here and sadly to say for the average hobbyist it is not really simple to regulate.

a) You could mix your electrolyte to a specific resistance by varying the ratio of washing soda to water but this is not easy to measure without specialised equipment.

b) You could use a regulated supply as shown above but this is expensive,

c) You could place a large 10watt wire wound resistor in line to limit the maximum delivered current to 300ma. Nominal values would be 40 Ohms for a 12v supply, 30 Ohm for a 9v supply or 20 Ohms for a 6v supply.

That said, plug packs vary greatly in voltage output both when under load and not under load so this is not a magic bullet. Also while the plug pack may not get too hot using this method the resistor will and so monitoring it is still required.

d) You can vary the distance between the item and the anode to achieve the desired resistance but again this is hard to measure for the hobbyist due to the equipment required.

e) What most people will do is just mix the electrolyte at the ratio specified, connect the plug pack in the correct polarity and monitor the process by way of placing your hand on the supply. Using a quality 1amp supply will not introduce enough current to damage an item and should be able to operate 15 or 20 minutes before becoming too hot to leave your hand on at which point it should be unplugged. That said .. DO NOT TAKE THIS FOR GRANTED!!! Unless using a regulated and cooled laboratory supply never leave the process un attended.

Also, it pays big dividend to use a small brushless fan to cool the supply or the resistors if you use that method. You can scrounge one from old electronics or buy one from a hobby store. If you choose carefully you will be able to power it from the same supply remembering to allow for the current load it will add. For your first experiments the fan will not be a must have item but for longevity of your set up it's a good idea.

Anode materials :-
------------------

The most common material used for your anode (which will have the positive lead attached) by home electrolytic cleaners is a stainless steel spoon. I can not stress this enough. Just don't use any stainless steel item as your sacrificial anode. If you do the process will result in Hexavalent Chromium being released into the electrolyte. See here :- http://www.workplace-hygiene.com/articl … pdate.html

Further, the resulting electrolyte becomes illegal to dispose of down the drain and must be allowed to evaporate and then the residue must be disposed of a a toxic waste facility.

I don't care what "Fred F***wit" from the "International metal detecting, asbestos munching and growing an extra head forums says" just DON'T mmmm k?

Likewise, don't use zinc plated metals for similar reasons.

Aluminium works although it results in a slower process (sometimes a good thing) but by far and away the best is plain old untreated mild steel available as offcuts at a metal work shop near you.

The anode will over time be eaten away and become covered in rust and impurities, it will require periodic scrubbing and will need to be replaced now and again. You can also clean it by connecting another sacrificial plate and reversing the polarity but this is a little counter intuitive to me as it requires higher current levels and if you're going to use another sacrificial plate you might as well replace the original.

Technique

a) Take your bath and mix the electrolyte as outlined above.

b) Place the sacrificial anode on one side of the bath. Ideally it will not be totally submerged. Clip the positive lead from your supply to the anode out of the water.

c) Take the item to be cleaned and make sure an area is clean enough to make electrical contact, You can gently rub a tiny out of the way area with 0000 steel wool if needed. Clip the negative lead to this place.

d) Submerge the item to be cleaned on the opposite side of the container to the anode, clamp it in place totally submerged with as little of the alligator clip on the negative lead in the water as possible.

e) Plug in the power supply.

At this point the item and probably the anode will start to bubble, the cleaning process has begun. How long it will take depends on the material being cleaned and the current passing through it. Thin alloy such as identification tags should be removed every minute or two and gently brushed and inspected and then replaced if more is required. Coins and buttons will generally require 5 to 10 minutes and larger items such as buckles may take half an hour or more.

As the item cleans it will become black from the process. This is nothing more than carbon. Once all the corrosion and other undesirable material has been dissolved place it in the palm of your hand over a sink and cover it with Sodium Bicarbonate. Add a dob of toothpaste and a few drops of water and mix into a smooth paste. Using a toothbrush firmly but gently brush the entire object with the paste removing all the carbon. At this point you can decide if your item needs to go back in the bath for another treatment.

Considerations

a) Electrolysis is a "line of sight" process. The area of the item being cleaned facing the anode will clean most effectively. You can either turn the item several times during the process or arrange your bath so that there is a sacrificial anode on each side of the bath and your item hangs in the middle.

b) At no time while in the bath should the postively charged anode be allowed to come into contact with the negatively charged item being cleaned. Should this take place while power is applied you will at the least blow your plug pack and potentially trip your home circuit breakers and start a fire. Some people place a plastic mesh in the middle of the bath but this can cause shadows on the item being cleaned due to "line of sight" effect. Simplest solution is just take great care.

c) While highly unlikely 300ma is many times the current required to disrupt and potentially stop the human heart under "perfect storm" conditions. You'd be more likely to win lotto than to die using < 24v and 300ma but still ALWAYS unplug the supply before inspecting, turning, brushing or touching the item in any way

You have been warned.

While every care has been made in preparation of these instructions and this process is undertaken safely by many thousands of people each year I accept NO responsibility for injury or negative results through failure to follow these instructions, unforeseen circumstances and the electrolytic cleaning process in general.

I may edit this guide at times as new techniques and information comes to hand and of course to correct the ever present spelling and grammar errors big_smile

Hope this helps

Regards
Dec

Hi Decado
Fantastic info there in that post smile
I have been considering electrolysis for a while to mainly clean old pennies etc.
Just bought a vibratory tumbler from eBay USA and waiting for delivery.
Cheers Monty


CTX 3030, X-Terra 705 Gold Pack, 6' 18.75kHz Round DD Coil, Pro-Find 25 Pinpointer plus lots of digging tools!!

#19

Wolfau
Guest
Guest
19 August 2014 09:40 am

Monty whats the ebay item number pls?

Thanks

#20

Monty
Member
From: Perth, WA
Joined: 01 January 2014
Posts: 127
Member
22 August 2014 08:35 pm

Wolfau

See if these details help (from eBay):

I am not sure where to find them exactly.

I entered Vibratory Tumbler in the search box on the eBay sight.

NEW!! 5 lb. Vibratory Jewelry Coin Metal Case Tumbler Polisher - VERY Cool Item
111217020713 - Quantity:1

Cheers. Monty.


CTX 3030, X-Terra 705 Gold Pack, 6' 18.75kHz Round DD Coil, Pro-Find 25 Pinpointer plus lots of digging tools!!

#21

Wolfau
Guest
Guest
22 August 2014 08:41 pm

Monty thank you so much.

That one is 110 volt.

Know what they look like now.

Silly question. How do we use it?

Last edited by Wolfau (22 August 2014 08:47 pm)

#22

Monty
Member
From: Perth, WA
Joined: 01 January 2014
Posts: 127
Member
22 August 2014 08:59 pm

Wolfau

You will need a step down transformer, this changes 240V AC to 110V AC, which this machine will operate on.

Don't try to plug it into our electricity supply directly - it will blow up!!

I have found one at Jaycar for $99, but have not bought one yet.

You will also need some polishing/tumbling media. I will be purchasing some crushed walnut shells to use (eBay again).

When you have all the above, fill the bowl to say about 1/2 full. Secure the lid and start the motor. You
should hear it going (vibrating). Turn the machine off, put some coins in (about 5 maybe a couple more),
secure the lid and start the machine.

I intend to put it on a timer, so that if I leave it for a while and forget about it, it will automatically turn off.

Not sure exactly how long to set the timer for yet, but will try 1/2 hr run time and check the progress of the cleaning.

I did see a uTube video on this somewhere, maybe stumbled on a link through this forum, but not really sure.

Hope this helps mate.

Cheers. Monty.


CTX 3030, X-Terra 705 Gold Pack, 6' 18.75kHz Round DD Coil, Pro-Find 25 Pinpointer plus lots of digging tools!!

#23

Wolfau
Guest
Guest
22 August 2014 09:04 pm

Thanks Monty i own 2 converters one is small and
A high wattage one.

Thanks for your help and advice.

1 user likes this post: Monty

#24

Goldpick
Moderator
From: Mount Gambier
Joined: 07 November 2013
Posts: 8,618
Moderator
22 August 2014 09:09 pm

Kellyco also do and range of tumblers and cleaning pellets/powder at reasonable prices.

http://www.kellycodetectors.com/accesso … nitems.htm


Prospecting gear: Used - Whites GM3, GM2, GMT, ML XT17000, ML X-Terra 305, Garrett Gold Stinger, Tesoro Vaquero, Nokta RS pinpointer, Minelab Explorer SE Pro/Etrac, Ace 250
Current - XP Deus, Equinox 600, Makro Racer 2, Fisher F75, Tesoro Tejon, Teknetics G2, Whites SPP, Garrett Infinium, XP MI-6, Whites Bullseye TRX, Deteknix X-pointer, Garrett AT Pointer

2 users like this post: Monty, Wolfau

#25

Wolfau
Guest
Guest
22 August 2014 09:15 pm

Goldpick wrote:

Kellyco also do and range of tumblers and cleaning pellets/powder at reasonable prices.

http://www.kellycodetectors.com/accesso … nitems.htm

Thanks Goldpick. Debating if i should head out
Tonight and do some detecting..


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