# Molten Lead Panning??



## NoIdea (Jul 25, 2012)

Evening All - doing something a wee bit out of the norm, im gunna ask a question about a posible process before actually trying it out first. :lol: 

We have all read or heard about using mercury to amalgum with the gold while panning, thus removing it from iron sand, my question is this, how would you think panning with molten lead? 

Over heat and taking all the necessary health and safety issues into consideration of course.

Thoughts Please

Thanks

Deano


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## publius (Jul 25, 2012)

I just finished a blood lead level screening. My level is 9.5 micrograms per deciliter. (One half a microgram higher and I would be required to enter a medical monitoring program) This is just from normal construction inspection related activities in existing structures and time spent as a part time employee on the sales floor of a pistol range.

Lead (Pb) fume will collect on clothing, hair etc and can be brought home to your loved ones. This is a very similar situation to how many housewives were found with asbestosis and silicosis.

In other words, don't do it...


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## qst42know (Jul 25, 2012)

Though I don't wish to promote the use of mercury in any way, but it has the advantage over lead in that it can be vaporized off and distilled easily. 

Are you looking to run a molten lead iron tumbler near 900F.?

Heat promotes oxidation, oxidation prevents fusion. What flux would you use?

Where would the smoke go, your own local environment?

You might be able to buy contaminated solder cheaper than you can make your own. :wink:


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## NoIdea (Jul 26, 2012)

Afternoon All - thanks for the replys.



qst42know said:


> Are you looking to run a molten lead iron tumbler near 900F.?



Im thinking hotter, maybe 600degC, and it will more than likely be a cast iron pot.



> Heat promotes oxidation, oxidation prevents fusion. What flux would you use?



From what i have experianced while going through my cupellation phase, :roll: , was that lead at a certain temperature the lead oxide became molten and stayed on top as a multi-coloured layer, this will protect the lead underneath. Cupellation involves the absorption of this layer thus exposing more lead for oxidation, in my case it says put.



> Where would the smoke go, your own local environment?



In my first post i mentioned that i would be "taking all the necessary health and safety issues into consideration". This includes any envronmental issues. Ok, that should cover any issues around lead and how bad it is. 8) 

So, with that said and done, does anyone think this would work?  

Cheers

Deano


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## Geo (Jul 26, 2012)

in the presence of molten lead, the melting temperature of gold will drop. whats to keep the gold from mixing with the lead or is that your intention?


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## NoIdea (Jul 26, 2012)

Geo said:


> in the presence of molten lead, the melting temperature of gold will drop. whats to keep the gold from mixing with the lead or is that your intention?



Hey Geo, yep, i want to produce the same effect as mercury, well sort of, i wish for the gold to migrate into the lead, thus separating it from iron sand, very fine iron sand and very fine gold.

Cheers

Deano


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## nickvc (Jul 26, 2012)

Deano as usual I like your thinking out of the box. I must admit if the safety issues can be properly addressed then it might be worth a try, I'd suggest a small trial batch and see if it works and how well as I'm inclined to think this might not be a known process or at least rarely used in the recovery of gold. Gold certainly likes to alloy itself so it might be worth the effort for the trial run, i think the lead will only be able to alloy so much gold but I doubt there's much written about how this will work or how well so you might well be on your own to determine it's effectiveness.
Good luck.


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## Geo (Jul 26, 2012)

with the right flux, you may be able to collect quite a bit of gold with very little lead. gold will adhere to every exposed area like it would mercury. the only setback i can see is you may not be able to do it in a metal container at all. i know that gold will bond to iron or steel, especially with the right kind of flux. it would be neat to have it set up like a shaker table where the material is passed over a pool of molten lead while vibrating. it should suck up any gold or silver that crosses over it.


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## qst42know (Jul 26, 2012)

Have you read this thread?

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=58&t=12450&hilit=7000+lead


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## NoIdea (Jul 26, 2012)

qst42know said:


> Have you read this thread?
> 
> http://goldrefiningforum.com/phpBB3/viewtopic.php?f=58&t=12450&hilit=7000+lead



Thank you very much, so to conclude, the answer to my question is "Yes".  

Deano


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## butcher (Jul 26, 2012)

At soldering temperatures the gold can somewhat dissolve into lead.

Bismuth added to lead, the alloy can be soldered with a match, or the alloy will melt in a coffee pot.

The experiment sounds interesting but I do not like the idea of having to separate a large batch of lead from the gold, well maybe you could put that large pile of animal bones to use.

And as alway's take precautions with your health, sure would hate to hear of someone getting lead poisioning.


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## NoIdea (Jul 27, 2012)

Thanks butcher.



butcher said:


> The experiment sounds interesting but I do not like the idea of having to separate a large batch of lead from the gold, well maybe you could put that large pile of animal bones to use.



Hmmm, yep, cupellation sound ideal, ah the bones, wonder how human bone would work. :mrgreen: Just kidding :mrgreen: 



> And as alway's take precautions with your health, sure would hate to hear of someone getting lead poisioning.



Due to our free health care here down under(apart from local GP visits, around $30NZ a pop) i get free blood tests, which i get every six months, all test normal, and that was before i started to get serious about health and safety, breathing all kinds of fumes, very very lucky. 8) 

The solder is from circuit boards, so thier is probably serious amounts of silver to.

Cheers

Deano


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## kurt (Jul 28, 2012)

Very interesting idea Deano - in fact I have recently been thinking along this same line the only difference being using tin as the collector for gold (to collect the fine gold wires from IC chip ash)

Yes I know that generally speaking tin is something we want to "remove first" in the recovery process &/or keep out of the refining process - but then generally speaking this true with lead also.

The idea is based on the principal of inquarting karat gold - only in this case you are not actually creating an alloy to be parted with acid but rather you are collecting particals by using a metal with a "much" lower melting point.

You should then be able to part the tin from the gold with nothing more then a HCL treatment being as how you have only "collected" particals of gold with the tin & not actually formed an alloy of the gold & tin.

Just a thought - open to comment

Kurt


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## kurt (Jul 28, 2012)

P.S. the reason I was thinking tin instead of lead is that tin lends its self better to acid treatment (HCL) to recover the gold then does lead - also more enviromental & health friendly.

Kurt


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## butcher (Jul 28, 2012)

I find lead fairly easy to deal with, I find tin just a nightmare.


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## NoIdea (Jul 28, 2012)

Tin?? Hmmm. How about zinc, then all one has to do is distill off the zinc, and from what a recall, gold and silver quite like zinc. 

Deano


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## jimdoc (Jul 28, 2012)

How about bismuth? I don't think zinc fumes are good to be dealing with.

Jim


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## kurt (Jul 29, 2012)

Butcher – Yes I agree – tin can be & often is a refiners nightmare – a nightmare we all encounter in working with refining PMs from electronic scrape. 

The tin we encounter comes from primarily 2 sources – one is the tin from solder & the other is tin alloyed with base metals (such as tin in brass pins)

The tin nightmare we all dread is the stannic tin (tin paste) we encounter when we dissolve base metal alloys that contain tin with nitric & end up with the stannic tin to deal with

On the other hand – with solder – the first thing we do is treat it with HCL to “eliminate” the tin before moving on to the next steps in our refining --- which is why “in theory” I have been thinking about using tin as a “collector” of fine gold (instead of mercury)

Deano’s post caught my attention because I had been thinking along the same line which is to use a “low” melting point metal as a collector (instead of mercury) to recover fine gold partials from concentrates (black sands &/or chip ash)

Lead, zinc, bismuth & tin have all been suggested

My thought for tin in this “theory” is as follows

(1)Tin is readily available (tin solder – same as we use for making stannous chloride – or recovered from CBs)
(2)Tin is cheap
(3)Tin has the lowest melting point @ 232 C. then bismuth @ 272 C. then lead @ 373 C. then zinc 420 C.
(4)Tin is easily eliminated with HCL (keep in mind we are only “collecting” the gold with tin – not alloying it with tin)
(5)Tin is relatively health & environmental friendly

Lead (1) readily available (2) fairly cheap (3) higher melting point (4) ether hot dilute nitric or cupelling to eliminate (5) not health & environmental friendly

Zinc (1) readily available (2) not so cheap (3) highest melting point (4) easily eliminated with HCL (5) not sure of health & environmental concerns

Bismuth – don’t know enough to comment

So – at least in theory – tin should not be a big problem – unless you actually smelted the tin with the gold to form a tin/gold alloy

Kurt


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## Harold_V (Jul 29, 2012)

Ultimately, you will always deal with an alloy, as molten tin will dissolve at least traces of gold, if not more. I suspect it will dissolve to the point of saturation given long enough exposure. 

Harold


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## qst42know (Jul 29, 2012)

Does this idea apply to ore panning or e-scrap ash?


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## galenrog (Jul 29, 2012)

Personally I think the idea of using molten lead to gather gold from placering concentrates is way too much trouble for me. I use commercially available lead free fluxes, kiln brick cut to size and a microwave for small smelts and a backyard propane/oxygen furnace for larger smelts. No need for a big pot of molten anything.

I would suggest a few days of study on the several mining forums that have threads on smelting. Once you have smelted gold, then you can get into the refining game. 

I would also suggest "How to Smelt Your Gold and Silver" by Hank Chapman, Jr. An excellent primer on smelting, which is about as far as most miner types go, although I am thinking about reserving several ounces of dore later this year to learn refining with.

Keep it simple.


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## bswartzwelder (Jul 31, 2012)

I have been giving a lot of thought to your question. OK, a little thought....only two brane cells left. One is lost and the other is out looking for it.

First, it seems to me that there was a thread about using a lead based flux for recovering gold from black sands. The flux captures the gold and everything floats on top of the molten gold. Later in the process, the recovered metals are reheated and the lead combines with oxygen from the air to form lead oxide which is a powder and leaves the gold behind.

Second thought, if lead combines with gold chemically, wouldn't solder on circuit boards dissolve some of the gold traces?

I made up several batches of flux, but don't have them in front of me. If you need the formulae, let me know and I'll dig them up and post them here.


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## NoIdea (Aug 1, 2012)

Hi bswartzwelder, thanks for the reply.



bswartzwelder said:


> I have been giving a lot of thought to your question. OK, a little thought....only two brane cells left. One is lost and the other is out looking for it.



Ha Ha Ha, i know the feeling. :lol: 



> Second thought, if lead combines with gold chemically, wouldn't solder on circuit boards dissolve some of the gold traces?



Yes, my thoughts exactly, their is a fare amount of gold left behind in the solder, not to mention silver. Though im not sure about the "chemically" bit tho. 8) 



> I made up several batches of flux, but don't have them in front of me. If you need the formulae, let me know and I'll dig them up and post them here.



I would be very interested in your flux formula.

Thans Heaps

Deano


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## qst42know (Aug 1, 2012)

For flux formulas you should study fire assaying. Some metals combine with lead readily others would need taken away in the molten slag and will need adjustments in the flux chemistry to do so.


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## bswartzwelder (Aug 2, 2012)

Sorry, NoIdea, but right now I can only find 1 formula for flux, but here it is:

1 Pound Litharge - Lead Oxide - PbO
1 pound Sodium Carbonate - Soda Ash - Na2CO3
35 grams flour
150 grams silica sand

This was meant to be used as a flux when trying to recover gold from black sands. If I run across the other formulae, I will post them as well. Let us know how all this works out.

I use a heat gun to heat cell phone boards (outside of course). I use a pair of pliers to hold the boards by one edge. When hot, I hit the edge of the board on a teflon coated baking sheet. Almost everything will fall off when done this way. Because of the teflon, nothing sticks to the sheet. You get all the components, flat packs, gold plated connector points, resistors, and solder. Lots of solder. Until now, I have simply thrown the solder away. Think I'll save if if you suspect it contains gold and silver. Now if there was just an easy way to get the silver off old chafing dishes and the likes.


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## NoIdea (Aug 2, 2012)

Thanks for the reply. This mixture looks very familiar, this mixture reduces lead oxide to lead which then absorbes metals of value and oxidzes the unwanted ones, pooling at the bottom of the crucible. I have used a mixture like this with mixed results, tho it was not with iron sand. 

My appologies, my intention is to use molten lead



bswartzwelder said:


> 1 Pound Litharge - Lead Oxide - PbO
> 1 pound Sodium Carbonate - Soda Ash - Na2CO3
> 35 grams flour
> 150 grams silica sand.
> ...



Well, from what i understand, lead based solder is being replaced by silver based solder, who and where i dont know, so i treat all solder as it may contain silver, any gold plated pins soldered will have some gold migrate into the solder, not to mention that still left on the boards. 

Excuse my ignorance, butt what are "old chafing dishes "?

Cheers

Deano


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## bswartzwelder (Aug 2, 2012)

Chafing dishes are like a bowl which sits in a stand. Under the stand, there is a platform or a really tiny bowl which holds a candle to keep the stuff in the upper bowl warm. These are for partys hosted or catered to by rich people. NAH, I never saw one up close till I ran across some at a secon hand/goodwill store.

I had some other instructions which went with the above flux formula. Here it is:
For every 75 grams of flux, add 30 grams of the black sand. Heat in a kiln to 1850 degrees for about an hour. Pour into a cast iron mold and cover the mold with a cardboard box or a metal pot. The glass produced by this operation will most likely shatter as it cools. The box or pot will contain the shards as it explodes.

If it hasn't already happened, remove all the glass from the lead by smashing it with a hammer. Place the lead into a cup called a cupel (It's pronounced Q-ple not cup-l, and is made from cement or bone ash and has a very thick bottom.) and place it back into the kiln. Heat it with the door open just a crack to 1000 degrees. The lead will combine with oxygen in the air and return back to lead oxide. The remaining button of metal contains all your valuables.

Non Reducing flux:

Chemicals in this formula will not reduce to form any other metal in the presence of gold. There will not be a button of lead present.

50% Ammonium Chloride
25% Sodium Nitrate
25% Borax

Mix equal parts of sample and flux. Heat in a kiln to 1850 degrees for about an hour. Pour into a cast iron mold and cover the mold with a cardboard box or metal pot. Glass produced by this method is likely to shatter as it cools.


Gold is not bright and shiny. Sounds like the gold looks more like sand.


I hope this one may help some as well.


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## butcher (Aug 2, 2012)

From the looks of that flux your making a substitute aqua regia in the melt, it would oxidize base metals as it would be an oxidizing melt, the base metal oxides would be in the glass of the borax, I also believe you would loose some of your gold due to volatility of the gold chloride fumes produced, look for yellow or violet stains in the cooler sections of your furnace.


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## nh6886 (Sep 22, 2012)

Hi Deano,

I am wondering if you gave this a try and if so what you results were. I have a few bags of black sand that contain some very fine gold I have tried a few different recovery methods but the black sand is almost as fine as the gold. I made a promise to avoid mercury to the guy who taught me to pan years ago so this sounds very interesting to me. Any way thanks for the thread I think this is the greatest idea/experience exchange I have ever seen and hope to add something worth while someday.

All the Best,
John


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## kurt (Sep 24, 2012)

Hi Deano

I to would be interested in hearing if you have tried anything discussed in this thread & how it turned out

Kurt


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## NoIdea (Sep 24, 2012)

Morning All - Sorry, butt no, nothing to date. I have just made a big move from a small town, 20,000 population, to the country. Fruit trees up the wa-zoo, chicken coop, glass house etc. It's spring here and the place was run down and im un-run-downing it. :?:  

The gold part has taken a back seat for the moment, butt once i have saved enough for supply's "i'll will be back"  

Cheers

Deano


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## nh6886 (Sep 24, 2012)

Deano/All

Only a slight variation to your original question here that was touched on earlier? If you ran your material across a bed of bismuth at say 1000F would the gold alloy with the bismuth? 
If it did could I simply cupel the bismuth/gold alloy to recover the gold? 
I realize this is different than collecting the fine gold in lead where you started but maybe a workable answer to a common problem.
I know you covered all the safety precautions being addressed and I am sure you know but to anyone who didn't assuring that your blacksand was absolutely DRY would be more important than I could express.
Sorry I know this is flurry of questions but that's kind of the way my brain works. 
Any comments or correction are greatly appreciated. 
All the Best
John


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## butcher (Sep 25, 2012)

Bismuth will collect the gold similar to lead, bismuth is also used to lower the melting point of metals, a mixture of bismuth and lead can melt at about the temperature of a hot cup of coffee, I think bismuth would probably be more expensive than lead.


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## nh6886 (Sep 26, 2012)

Thanks for the reply Butcher,

I hope I'm not hijacking this thread to badly but I do have a couple of other questions.
Will the Bi collect the Au at 1000F or absorb it? (not sure if that's the right term)
If it absorbs it will it be better to cupel it or treat it chemically?
I am starting 1000F because the Bi seems to be pretty low in viscosity at that temperature but as in everything else I am open to advice on this and will experiment as I move forward.
My plan is to introduce the material below the surface with a ceramic tube so that it will float up through the molten Bi.
I have a couple of pounds of Bi on hand that came from RotoMetals it is 99.99 pure and cost about US$22 per pound.
You could add in the cost of one crucible if you received credit for not accounting for the expansion of Bi as it cools thats normally abbreviated as DUMB.
I would use lead if it has advantages other than price?

All the best,
John


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## butcher (Sep 26, 2012)

As I understand it bismuth can be used as a collector in an assay and cupeled, I have bismuth but never tried, I suspect like tin it could collect gold at a much lower temperature, in an assay you are trying to get several metals to oxidize to be able to go into the slag, or you are trying to keep valuable metals from oxidizing in the chemistry melt of the ore and to form a button, collectors like lead or bismuth can help to collect the values into one mass of metal, also you may have silica and other minerals in the melt to get into a molten state to get into slag this is where flux and high temperature of the melt are chosen to get the desired chemistry of the melt to collect values into a button and oxidize other materials into the slag.

What I would do is get some clean gold foils, these could come from a few memory cards using the acid peroxide process to remove the gold foils, use these in small experiments with the bismuth, I would try lower temperatures at first as bismuth has a low melting point and it would lower the gold’s melting point when mixed, unless there is other material that would need oxidizing, or reducing (as in ore or base metals) in your experiment then you would need a flux like in the assay, and higher temperatures as in a furnace. Taking weights and careful notes you should be able to come up with what works best for a process.


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## nh6886 (Sep 27, 2012)

Fantastic!
I have about 5 grams of finger foils from AP.
I will do this over the weekend and post my results. I may finally have something to give back in a small way.
Thank you,
John


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## nh6886 (Dec 24, 2012)

Deano

Just a quick note I was doing some reading this morning and saw this bit on lead refining and thought of your post. Here's the link if you want to give it a look.
http://books.google.com/books?id=0m-JuMpFZPAC&pg=PA200&dq=precious+Metal+refining&hl=en&sa=X&ei=b7bYUN3MAaOiiQK17oH4BQ&ved=0CEkQ6AEwAzgK#v=onepage&q=precious%20Metal%20refining&f=false
It mentions the way that they are refining lead and recoving their PM with the Parkes process and it got me thinking about this thread again so I thought I would share.
By the way I did try adding the gold foils into the bismuth like Butcher mentioned above and it alloyed into the Bi at around 750F. I proved it up with a XRF check of the surface finding the Au not perfectly alloyed but certainly present throughout. I have not cupelled the Bi yet as the Au is less than 1% so I am going to run some black sand through it first to try and add some fines and eliminate the black sand and what I believe to be zircon sand that is better at staying with the Au than I am at panning. I hope to get the Au to at least 5% before cupelation. So now I have to start looking into the next steps. I am going to put the whole experiment into a new post when I get the results.

All the best,
John


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## ericrm (Dec 24, 2012)

do someone knows if one could use molten zinc to alloy gold?


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## qst42know (Dec 25, 2012)

Yes, but with it's own set of problems.

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


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## Pantherlikher (Dec 25, 2012)

I still like Deno's thought process... Lead might be a tad off unless you get wheel weights free...
Tin, lead and silver however, is something that comes from E-waste of any kind. And a by-product of E-waste. Maybe Deno can use his unique hamster wheel and work on refinning Tin and end up with by-products like Lead, Silver, Gold and other worth while metals.

This would help solve his idea if viable as well as solve the Solder "what the hell do we do" with issue.

BS.
Sometimes the mass dissalusional, kaotic mind is the right way to go...
:lol:


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## NoIdea (Dec 25, 2012)

nh6886 said:


> Deano
> 
> Just a quick note I was doing some reading this morning and saw this bit on lead refining and thought of your post. Here's the link if you want to give it a look.
> http://books.google.com/books?id=0m-JuMpFZPAC&pg=PA200&dq=precious+Metal+refining&hl=en&sa=X&ei=b7bYUN3MAaOiiQK17oH4BQ&ved=0CEkQ6AEwAzgK#v=onepage&q=precious%20Metal%20refining&f=false
> ...



Thanks John, pretty much where i want to go. Part of my new years resal... rezilu........ you know that thingy you say at the beginning of the new year, well it's gunna be part of that :lol: 

Pantherlikher Quoted: "Sometimes the mass dissalusional, kaotic mind is the right way to go..."

Here here, would not have it any other way. Oh you might want to add querky and unpredictable in there somewhere too. :mrgreen: 

Merry Christmas too you all

Deano


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