Classifier Sieves information and questions

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Totally agree agman but just pointing out these smaller sieves at bunning's as we don't all go after the yellow and they can be cheap & useful in other area's.
People do pay excessive prices for this sieve in other places include Ebay. About $30 + postage on Ebay and about $5.99 at bunning's. This size sieve works very well at the beach with a bicycle tube on outside and piece of string tied to waist.
 
Thanks Dave - I never really gave it much thought to sieve stuff at the beach if one was detecting - learn something every day ;)
 
This works very well, 1/ get a signal 2/ shovel signal to sieve 3/ start detecting again and by the time you find another signal all the sand should have washed threw and with some luck you have treasure & not rubbish. All with no effort except the initial digging of signal water action does the rest. This is very useful in shallow water only.
 
On the gold I'm with you Ag man....Don't classify less than 1/4 " ....brother classified with 1/8" sieve near Wee Jasper a few years back for 1/2 gram of rough gold in about 4 hours work. Towards the end he noticed a yellow flash while flipping the sieve..and was shocked he threw out a small bit. :( . Luckily he's a sapphire man and flipped the sieves into a small pile...long story short...we reclassified the pile with 1/4" sieve and too our amazement found 7 bits that just stayed in the 1/8" sieve. :mad: Those 7 bits ended up weighing 1.6 grams....hard lesson learned.
 
Now I'm thinking about the stuff I used to throw away and cringing, I am now using a 1/4 inch sieve as I have been watching a bit of youtube and all of the people are using 1/4 inch and bigger. Like you say a lesson learned.
 
has anyone seen a supplier for 2 mm sieves ?

there are heaps of 1/8" , 1/4" and 1/2" ones around but i want 2 mm ( and maybe even 1 mm ) to pre process fines before i put them through a blue bowl

any suggestions ?

some of the prices out there for sieves is a joke

$ 40 - 79 bucks each

if the same thing was available from my local farming co-op it would be under $ 19 and twice the quality
 
Mate, have a look at the screen I made in this thread, https://www.prospectingaustralia.com/forum/viewtopic.php?id=2342

If you buy the aluminium fly mesh it will last longer, the holes are around 1.xx mm or smaller, if you need a finer grade, you can use the fat guards you can get from coles or kmart for like $3.00 also.

If you want to buy one you wil need around a 1/20 or 20 mesh, or; 1/30 or 30 mesh.. 30 holes or wires per inch, that should be around 1mm if you want sub mm then you need to go for a 1/50..

Good luck, Tone
 
If you know for sure the gold is sub mm size (like the stuff I've been finding lately) you could always use a cooking sieve, i got mine for a dollar and the holes are about 3/4 mill wide
 
garnethawkins said:
If you know for sure the gold is sub mm size (like the stuff I've been finding lately) you could always use a cooking sieve, i got mine for a dollar and the holes are about 3/4 mill wide
Click to expand...

yes i used one myself the other night before putting it in the blue bowl but they are a bit of stuffing around . i am hoping to have all my sieves fitting inside each other neatly , and fitting neatly into the 20 litre plastic buckets so i have no spillage and its a fast efficient process

i might have to run two separate batches in the blue bowl too

filter out with a 2 mm sieve and also a 0.3 mm under that

i have been getting a little gold so fine you cant see it until its bunched together , its like talcum powder and the blue bowl spits it out if i try to run it with the normal shoalhaven catch of 0.2 mm - 3 mm flecks

grading by multiple sieves is essential
 
Geez your picking up some fine gold there Headsup. If you look at the link to my post you will see a pic of a couple of sieves i made. the white bucket sieve is aroynd 1/8 in or 3.2 mm, the paint tin sieve is the wire mesh.i sieved through both and process each size seperate. i did put the fly mesh material through one of the fat guards and it did filter out a bit more fines.. If you are moving an lot of material often, I would invest in the best set of fine sieves I could afford. Most Screens i have seen run around $40 mark. just contact one of the sponsors and imsure you will get a good price. I would go for a 1/8, 1/20 + 1/50. this shiuld catch EVERYTHING.. You may find the sub 1/20 will not stay in the blue bowl or you will have to turn flow way down to ensure you dont wash the gold out. I suggest you just clean the sum 1/20 in a pan and use a snifter to gently push or suck up the sands away and leave gold in pan and a seperate sifter for gold..
good luck with it. Tone
 
TenOunce Tone said:
Mate, have a look at the screen I made in this thread, https://www.prospectingaustralia.com/forum/viewtopic.php?id=2342

If you buy the aluminium fly mesh it will last longer, the holes are around 1.xx mm or smaller, if you need a finer grade, you can use the fat guards you can get from coles or kmart for like $3.00 also.

If you want to buy one you wil need around a 1/20 or 20 mesh, or; 1/30 or 30 mesh.. 30 holes or wires per inch, that should be around 1mm if you want sub mm then you need to go for a 1/50..

Good luck, Tone
Click to expand...

You took the words out of my mouth tone was about to post link then say you had already done it
 
TenOunce Tone said:
Geez your picking up some fine gold there Headsup. If you look at the link to my post you will see a pic of a couple of sieves i made. the white bucket sieve is aroynd 1/8 in or 3.2 mm, the paint tin sieve is the wire mesh.i sieved through both and process each size seperate. i did put the fly mesh material through one of the fat guards and it did filter out a bit more fines.. If you are moving an lot of material often, I would invest in the best set of fine sieves I could afford. Most Screens i have seen run around $40 mark. just contact one of the sponsors and imsure you will get a good price. I would go for a 1/8, 1/20 + 1/50. this shiuld catch EVERYTHING.. You may find the sub 1/20 will not stay in the blue bowl or you will have to turn flow way down to ensure you dont wash the gold out. I suggest you just clean the 1/20 in a pan and use a snifter to gently push or suck up the sands away and leave gold in pan and a seperate sifter for gold..
good luck with it. Tone
Click to expand...

yeah i tired that with the talcum powder stuff but was just chasing my azz in circles trying to get it away from the black sand

its like fairy floss in a cyclone :(

waiting for a delivery price on this set below and hopefully i can screen the stuff down in stages , turn the bowl down low , dont add the gold until the water flow has stabilised , and use rinse aid . fingers crossed it might work.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130858599224&fromMakeTrack=true

eidted . i posted the wrong URL above
 
Another option may be smelt the fine gold. the impurities should burn out.. never done it but im sure others can advise on best practice to smelt the small stuff.. just clwan up as best you can i guess..
 
TenOunce Tone said:
Another option may be smelt the fine gold. the impurities should burn out.. never done it but im sure others can advise on best practice to smelt the small stuff.. just clwan up as best you can i guess..
Click to expand...

i tried that last week too :8

i think i used too much flux and ended up with the flux setting rock hard like glass and all i can see is tiny balls of gold underneath the flux :8 :eek: 8.(

the flux was supposed to be the right stuff for gold . i hope . (ebay job ) :eek:

LOL

dunno what to blame there , the made in china crucible , the ebayed flux , or the guy holding the oxy torch . haha :)

i shall work it out eventually
 
If the postage ends up too much you can try these guys http://www.prospectingsupplies.com.au/products/150-14-diameter-sieves-various-mesh-sizes.aspx

I screen all the way down to -100 and run the -100,-50, -30 all through the blue bowl.
Plus 30 goes through a little mini sluice set up.

You'd be surprised at how much of the super fine gold you end up collecting which would have been thrown away.

I've put this up before but link shows washing material via stackable screens but you can't run a lot through each time as important not to overload them.
http://prospectingchannel.com/process-gold-concentrate.html

I basically just bring cons home from the highbanker and get whatever gold is easy to get up through sucker bottle , rest goes in 20 litre buckets which then get screened down into 30+, 30- through to -100 and will spend a day or 2 every 3-4 months running the lot through the bluey. The collective result is usually quite a substantial amount and is all going to my GPX5000 fund.
 
Have you had a chance to use your screens and blue bowl yrt Headsup. I found an old tea infuser in the kitchen today. It has s real fine stainless mesh. I put some black sand and in and gave it s shake.. low and behold some really small gold was in the ultra fines... had a look with yhe 10x loupe and there is a fair bit of really fine gold in there.. will have a bit more of a play in the daylight and see uf i can get a pic through yhe loupe..

Judt goes to shiw how much hold we throw out!!
I was looking at this spiral gravity trap design today. It is a comervial scale device. 50+ ton an hour but it catches down to 30 micron. I will put a link to it soon.
 

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