Cleaning Nuggets

This could be difficult or hard depending on what state the nugget is in.

If there is not much dirt on it, try some toothpaste and an old brush. This brings it up well.
However if there is ironstone or quartz then acid, or mag wheel cleaner is the go.
Can members enlighten us.

Jeff

Read on another forum that some people are using a Digital Ultrasonic Cleaner
Apparently some Aldi stores have them for $40.....had a look at some different ones on Ebay from $100 and up
Good for cleaning dentures coins jewelry ect...

I agree that a little toothpaste (which often contains a minute powdered abrasive) will clean a slightly stained nugget up nicely. I like to soak nuggets for a while in water before dropping them into an ultrasonic cleaner for 3 minutes. I always use a plastic tray on the metal chamber so the gold doesn't get scratched.

Hydrofluoric Acid:
Just beware the Hydrofluoric Acids. NASTY stuff and yet so many Prospectors use it to clean nuggets with! A fatal dose is usually not noticeable because the nature of this acid means it penetrates the skin before the molecules become active so there may not be a physical trauma on the site of the contamination. A mere drop on the skin leeches towards the calcium in the bones and often results in amputation and/or death within a week. Most accidents with Hydrofluoric Acid are minor (ie victim opens bottle and gets a minute amount on hands from the neck of the bottle) yet the consequences are potentially lethal each time. Vapor from the bottle is enough to burn the corneas of a person's eyeballs. This acid eats through glass and it useful as an etching agent. Fatal Dose is believed to be just 1.5mg if ingested. Two drops or more on the skin is usually fatal. From memory, one treatment is to split the skin near the site of the spill and apply calcium splints to the tissue to leech out the Hydrogen and Fluoride ions. A calcium intravenous drip may also be used. Death was recorded within 6.5 hours with the accidental ingestion of just 1.5 mg. 50 ppm exposure for just 15 minutes (vapor) resulted in a recorded death. FBI lists this liquid as one of the most deadly chemicals on the earth. This acid is often found diluted in car tires and engine cleaning liquids and is the active ingredient in the cleaner used to clean mag wheels. Nuggets cleaned with HF Acid tend to result in a bright yellow state and without stains or blemishes on the surface. Some collector will not buy such nuggets and prefer them to be exactly as found. Others will ignore naturally stained nuggets and will instead seek out the cleaned nuggets for collections.

Oxalic Acid:
I use Oxalic acid from the Prospecting supply stores and it's MUCH less dangerous. It cost me about AUD$21 for a 1.5 liter bottle of powder. It's not as reactive and is often used as a rust cleaner. This powder is added to water to create a bath solution for the nugget. The downside is that it's very slow working compared to the previous acid. The upside is that it's much safer to work with. Hydrofluoric Acid eats away host rock and quartz in a matter of 48 hours or so whereas Oxalic Acid takes weeks to clean a nugget. Sometimes months. It occasionally fails with certain specimens with high volumes of ironstone/quartz etc. But it does work and it's considerably safer to work with by comparison. Fatal dose is listed as being 5 to 15mg.

I'd also suggest the use of a cheap electric toothbrush with plastic bristles to assist in cleaning more of the most stubborn dirt from a nugget. I keep a selection of needles and needle-tipped tweezers on hand to remove tiny grains of host quartz and ironstone from some specimens. Splitting the smaller grains of quartz before extracting them may take more effort but works sometimes. Just be careful to avoid scratching your nuggets!

saltbush wrote:Read on another forum that some people are using a Digital Ultrasonic Cleaner
Apparently some Aldi stores have them for $40.....had a look at some different ones on Ebay from $100 and up
Good for cleaning dentures coins jewelry ect...

Friend got one of those Aldi ones -worked brilliant on his coins he said. Don't know if he tried on nuggets yet though.

Hi All
Ali Brite Aluminium cleaner does a great job.However it Does contain Hydroflouric and Sulfuric acid so follow the safety instructions.Its sold at Supercheap Auto Stores in 1 litre bottles about $16.I use plastic peanut butter container place the nuggets in pour in Alibrite depth 50mm and let sit for week or so.Wear gloves and when you unscrew the lid be mindful of drips from the cap.Run water from a hose outside into the container(Dont put down sink as is corrosive)to dilute and displace alibrite.I use an area that ash is spread from coonara and hose it well.A teaspoon of Bicarbinate of soda is then placed in the container,3/4 full of water cap on and give it a good shake.Empty 3/4 water a drop of dishwashing good shake .Ali Brite works well on ironstone ,but takes longer for Quartz.
Cheers Dig

Found a product called s weld clean its basically called pickelling paste for cleaning stainless steel after welding contains 50grams per ltr hydroflouric acid.Does break down quartz into a hard chaulky compound after a couple of days . After cleaning drop the gold into bicarb soda i would suggest you use rubber gloves whilst using this chemical have fun im sure you will be happy with the outcome GOOD HUNTIN GOINBUSH

Sounds like a new product - or one I've missed. Hydrofluoric Acid is often featured in rust cleaner and tire rim solvents but for GOD'S sake be careful with that stuff. I don't think it will be anywhere near concentrated enough to destroy quartz at that percentage. I can assure you that there's still enough in that mixture to kill you. It only requires 50 parts per million to be fatal when inhaled and full thickness burns are usually caused by much weaker solutions. If you want to try it out, be sure to dispose of your rubber gloves after handling it and use a mask to avoid any vapors. OHS recommends wearing a second set of thin latex gloves beneath the handling gloves just in case the first set has a leak. I would guess that the mixture would certainly clean nuggets of any stains and would work a lot faster than Oxalic acid for this purpose. But I suspect it would be too weak to break down stone or quartz at this concentration though.

Cheers!

Hi All
I remember a boilermaker on a job once told me that dont get that paste on you it can be absorbed through the skin and into your bones & breaks them down nasty stuff. Some research is in order if you intend on using this stuff.
be careful
cheers
Lee

Hi All
Places to find this type of cleaner are those dealing with welding supplies eg BOC Gasses, Welders world.
cheers
Lee

hi all
my son is a second year apprentice fitter they do alot of packaging machinery that come into there work .he was telling me they use AEROGARD when cleaning so I tride it the other day and it worked pritty good so if you dont wont to play with all them chemicals give it a try . I used tropical strength ( pump ) not aerosol. not to say that it will not work. you can pore it out easy
......... HASSA ......

hi all
  another one that works well is an industrial product called aluminium brightener or aluminium cleaner.  it has a very small amount of hydrofluric acid in it(check the label to see if it has hydrofluric acid in it).like the others said,hydrofluric is lethal,do not get it in your eyes, & wash with heaps of water if you get it on you.
 a good thing to clean your little nuggets in is the plastic 35mm film canisters.  leave the nuggets in the brightener for about 3 or 4 weeks and every now and then give the cannister a bit of a shake.  the alu cleaner will completley disolve iron stone and will leach quarts bone white.it also takes all the dirt out of nuggets and after cleaning they look amazingly bright.
 

Hi All
Alibrite from supercheap auto stores does a good job
Cheers Dig

For nuggets that simply need the dirt cleaned off them, I can highly recommend an ultrasonic cleaner. Try eBay and look for a good one.
You will be a winner with the girls as a side line. They are great for cleaning jewelery.
Nothing dangerous about these things unless you put your finger in the water while its working.(You will only do it once). Its like putting your tongue on a 9 volt battery multiplied x 10 only difference is its your finger.
Brett.

Hi All,
Well all the ways to clean gold is fine, have used most of them with good out come. But if you have a nugget that you want to shine and is for a friend to ware, rub it with a stainless steel tea spoon it makes the high bits real bright..try it on a not so good nugget first just in case ...Bob

Hello All
Back in the 70's and 80's I used to use a lot of hydroflouric acid to clean nuggets. It was great for getting rid of small pieces of rock etc out of them but I don't want to go near the stuff again - too deadly for my liking now.
I've found some bits with a ferro cement skin on them. Ferro cement is an extremely hard (hence the name "cement"), iron based sediment, very common over here and nuggets are often found at depth in it. Very hard to dig them out, sometimes taking hours. I've tried some hydrochloric for cleaning nuggets coated with the material but with little or no effect. The skin is only microns thick but the hydrochloric won't touch it.
Does anyone have any suggestions as to what I might use that is relatively safe.
cheers
Brett

have you tried heating the nuggets up and quenching them in the acid? That is heating them up and dipping them in the acid whilst still hot enough to give off a small fizzing noise. We use this method to clean off oxidisation from our gold at work. I've never tried it on a nugget though.

dicko..

I use boss pickling gel its for cleaning stainless steel after its been welded .It contains hydroflouric acid 50g/l nitric acid 300g/l you can get it at most industrial supply welding supply places .Leave it for a day and you should be happy with the results .its about 60 bucks a bottle but goes a hell of a long way . hope this helps good huntin GOINBUSH there are 3 small bits in the photo gallery but in different areas the 3 dirty ones are the same nuggets after they we in cleaning overnight have a look at the result.

Thanks Goinbush, I'll check out our boatbuilder here, he should give me a bit to try.
cheers
Brett

I've used nitric in the past for fizzing off the cement
Alan

Gday

I was told that jewellers use what they call "Pickle" to clean gold after soldering and such, apparently its Sulpuric acid, the same strength as standard battery acid.

I generally use hydrochloric acid for cleaning nuggets, its relatively safe but it does require some time,and effort, usually I leave the bits in it for about a week, take them out and give them a wash in some soapy water, then I use a dentists pick to scratch and pry the softened rock/mud etc, it wont touch the quartz of course but it gets rid of most other stone and coatings such as calcrete, sometimes I will put them back in for a few more days if i am not happy with the result, and then remove them and give them a good clean with a toothbrush and soapy water.

You really need to wear gloves and glasses, the acid is not bad to use and you can wash it off if you get it on your hands, but if you happen to drop something or tip it over you can end up with it in your eyes or on another part of you thats not as tough as your hands, its a lot safer than using hydroflouric and I wouldnt recommend that anybody use that unless they are very experienced with it.

With hydroflouric acid I have also been told that you need to wear VINYL gloves not rubber/latex ones as it can penetrate them and once its on you, you can be in serious trouble,you also really need to wear eye protection and protective clothing, and you have to have somewhere really safe to store it if you have kids or whatever, really I think its best left alone.

cheers

stayyerAU

Thanks guys
I'll give the nitric a go first I think as that is a whole way safer than the hydroflouric solutions.
I tried the hydrochloric over the last couple of weeks Stayyer and it hasn't touched the cement but it brightens up the ordinary dirty nuggs.
cheers
Brett

hi mulga,
i used to use hydrofluoric but chap who sold it to me wouldnt do so until i signed a clearance form from liability, and also buy a tube of calcium gluconate gel (to nutralise any acid problems on yourself - is dear at $35 a 50 gram tube, but i used it once after a accident and had no followon problems).

gave that away after a mate put me onto ALI BRITE a aluminium cleaner, by septone.
is hydrofluoric at 9.8g per thousand ie 1% and sulfuric at 46g per thousand ie 4.6%,
works good, a lot slower, one to two weeks, but that gives you a better chance to check out if it is a good specimen, and it doesnt leave the remaining squartz crumbly.

ran into a fella who used to boil his nuggets in a mixture of battery, sulfuric, acid with about 80% water.
within a hour, all quartz was gone, and the gold left was the most brilliant golden colour i have ever seen.
tried it myself in some earthenware pot and had a total disaster, as the pot broke. i might add he used a ordinary aluminum cook pot, sat at the stove while it boiled away, and i had to ask the obvious question,
"" do you use that pot to cook your tucker in?"" the answer was YES. (i might add he is in his eighties and dying slowly of prostate cancer and couldnt give a stuff if something takes him out beforehand... kev

Mulga
Kev is spot on with ALIBRITE,Does a great job,Supercheap Auto stores sell it ,but havent seen it anywhere else
Cheers Dig

Once upon a time I used to use HF Acid, I had the gold in a suitable plastic bottle sitting in a bed of alum in a locked cabinet. Came home one day and took it out checked it a returned it without opening.

One hour later three fingers on right hand started throbbing and a white spot appeared on the edge of each nail. Whacked on the Sodium Glutomate gell from the fridge and took off for hospital. The nails of the three fingers were removed (snipe nosed pliers under the nail to full length than squeezed and rolled off the nail like opening a tin of sardines!) Nail beds were then injected with sodium glutomate solution, packed and padded and then bandaged and sent home with some very strong pain killers!

Be careful when using this stuff it can and has led to fatalities. I new knew the risks and treatments but did not take into account the tiny crack in the top of the bottle which had allowe some fumes to escape. I had not opened the bottle. Today I use Alibrite and leave it as long as it takes.

Cheers John

PS> Initially the male nurse who saw me stated that he did not know much about HF burns but thought a good wash and some painkiller would be OK "Come back tomorrow if there is still a problem" Needless to say he got a short, sharp response and told to get a DR chop smart.

Sounds pretty shitty John and exactly why I don't want to have anything to do with the HF acid again. I guess you were pretty lucky as it turned out, the stuff is deadly and at least you're still here.
We used to order in 1 litre bottles of the stuff from our local Elders store and got away with handling it for several years without any issues, probably more by good luck than good management. Don't want to have anything to do with it again.
Apparently if HF is mixed with Nitric acid it forms a substance called Aqua Regia, the only substance that will completely dissolve gold to an unrecoverable state.
I'm still wary of the Alibrite, as apparently it contains small amounts of HF acid.
cheers
Brett

Gday Brett


Aqua Regia is a combination of Hydrochloric acid and Nitric acid, I dont know that I would recommend mixing the HF with Nitric, dont know what you would get then, but my best guess is you would be able to see the results for some distance



"AQUA REGIA"

Aqua Regia can dissolve gold because each of its two component acids carries out a different function:

The Nitric acid is a good oxidising agent, and the chloride ions from the Hydrochloric acid form coordination complexes with the gold ions removing them from the solution.



So if you do this then your gold will dissapear I cant remember if it is recoverable from the solution or not, i dont think it is, maybe someone else can enlighten us?

cheers

stayyerAU

I have refined gold using the Mixed acids and my suggestion to anyone who does not know what they are doing leave it well alone and the hF acid should not even be sold.
I was refining with a friend who used to run gold refiners of aust and he knows his stuff but the more I learn't the more I realized how much I didn't know.
Yes gold can be extracted from the Aqua regia and that is one of the last processes and you add sodium bisulphate and the gold comes out of solution and rains down in the beaker and looks like mud.
This is then filtered off and looks like brown coffee , heated with a pinch of phosphorous to burn off any impurities and you are left with a bright shiny gold bar.
All sorts of other processes are used to neutralise acids ect and the fumes are deadly.
The last time I refined I got some solution on my hand which was safe but was photo reactive and when I washed up and went outside and the light got to my skin it turned purple and took a week to wear off.
My friend said just wash your hands in this cyanide and it will instantly come off ,I do it all the time , and if you start to feel something he has an injection in the fridge to stop the poisoning from killing me if things go bad.
That was it for me and I now have no interest in ever doing this again.
Mark

Gday Stayyer,Mark,
Thanks guys. I have absolutely no intention of making any concoctions up!!
I think I'll give the nitric a shot .
cheers
Brett

On initial advice I used Hydrochloric acid at first and finished off with water and bicarb of soda to neutralise in finishing off. My few pieces that I have were still very dull at that point. Maybe I should have left them in the acid for longer. Dunno? So I decided to try Allibrite and now they look the real deal Its worked a treat. Thanks for the safety advice as well.
.

Mal

I was using toothpaste till now. Seems like this forum people have experience more then what I did in past. There are lot of advice in this forum and seem to be really good and advisable. I heard that some chemical usage will lust the gold jewelry so never took a chance of any other liquid.