Drywasher riffle cloth

[God's Money]

I am very new to this stuff and the only mentor I have is my wife and she knows nothing!

I have spent hours upon hours searching the net for information on building a drywasher (puffer style) like most topics, much is just regurgitated on the net. I am no good with stuff like CAD and for that matter not even very skilled with a pencil drawing, in my head type of bloke so I just started building. The question I have as a novice to prospecting is why is Stainless steel woven mesh dismissed for material under the riffles. And has anyone ever tried it?

 

[Keitzy]

Doubt itd be woven tight enough and costing... bonds singlets worked good and cheap as riffle tray cloth in mine

 

[God's Money]

Doubt itd be woven tight enough and costing... bonds singlets worked good and cheap as riffle tray cloth in mine

I would not call it costly (cost about $10 for a strip 300x1000. I am not sure what you mean by tight enough. this mesh I have used in irrigation water filters its pretty robust and consistently woven. you can get 125 micron. sorry I can't give links.

 

[Goldfreak]

Yes you can get very tight woven stainless mesh. I have never seen it done with a dry blower but imagine it would be very durable. " the only mentor I have is my wife but she knows nothing " that made me laugh. The pure passive aggressiveness was beautiful :lol:

 

[Nightjar]

GM,
Steel mesh is a good idea when placed under cloth mesh, it supports the fines load spilling onto the riffle box.
The cloth is used because with every puff the cloth flexes upside of riffles agitating the fines, the light material spills over the ridge and the same process is repeated at every riffle. When angle and bellow stroke is set correctly gold usually doesn't get past the top two riffles.
The angle is around 21.
Get your self a small two way spirit level (most caravan outlets have them) glue it to horizontal frame of dry blower, set your riffle box angle (21) at home on level floor.
Then when you get to your dryblowing destination the setup is a simple matter of leveling the machine.
BTW any tight mesh cloth is suitable, fitted flour bag cloth to my mini dryblower. (picked up at Op Shop for a couple of $$'s.)

Good luck.

 

[Keitzy]

Stainless mesh under maybe, not over. I used old flyscreen under the cloth for support. I could not see how stainless mesh as the cloth would work any good.

Fly screen under the tray..

 

[CreviceSucker]

Wouldnt a polyester cloth on top work better due to its static generating properties ?

It would hold fine gold better woodentit ?

Dunno if the stainless mesh would earth the static out or not

 

[bluejeansronald]

Wouldnt a polyester cloth on top work better due to its static generating properties ?

It would hold fine gold better woodentit ?

Dunno if the stainless mesh would earth the static out or not

Hi Mate, Reeds prospecting carry the good cloth keen u/s use, Ron,

 

[Ded Driver]

The cloth wont build up any static while it has water running over it. The water acts as a conductor & effectively earths it

 

[Eluvial]

No water in a drywasher Ded. :Y:

 

[Nightjar]

Dry blowers, not dry washers, WA's old timers would be rolling in their graves hearing this.
Forget about static electricity, yes fly wire under the cloth.
Riffle height is not really important, the higher the riffle the more fines retained, more fines means more washing/sluicing (using water layful: )at end of day.

GM, when you get your machine trialing a sure way to check performance is to wash fines from upside of each riffle. Gold should not get past the first two riffles.
Top screen mesh approx 10mm.
Always check top screen, move machine away from the spill at end of day and run your detector over piles to check for the any "big ones"
Back in the early 90's we found a lot of gold retreating the "old fellas" dry blowing heaps, surprising how much they walked away from. One reason I suppose, there was an abundance of gold and they didn't waste their time getting the crumbs and mustard gold.

 

[Ded Driver]

my fail sorry, I didn't read it well enough to think about the 'dry' bit :argh:

 

[Moneybox]

Dry blowers, not dry washers, WA's old timers would be rolling in their graves hearing this.
Forget about static electricity, yes fly wire under the cloth.
Riffle height is not really important, the higher the riffle the more fines retained, more fines means more washing/sluicing (using water layful: )at end of day.

GM, when you get your machine trialing a sure way to check performance is to wash fines from upside of each riffle. Gold should not get past the first two riffles.
Top screen mesh approx 10mm.
Always check top screen, move machine away from the spill at end of day and run your detector over piles to check for the any "big ones"
Back in the early 90's we found a lot of gold retreating the "old fellas" dry blowing heaps, surprising how much they walked away from. One reason I suppose, there was an abundance of gold and they didn't waste their time getting the crumbs and mustard gold.

Peter, I tried to dryblow these old fines piles but found that they were missing the fine dust needed to get the dryblower to actually puff. The air just escaped through the loose gravel. Perhaps I should give it another go?

 

[Nightjar]

Hi Moneybox,
Sounds to me like the cloth you are using is too porous, running empty you should see the cloth lift slightly with each puff.
Another indication is fine dust ends up in the blower chamber, (filtering through the cloth when the blower takes a breath)
Old dry blowings are definitely worth a rerun.

 

[Moneybox]

Yes I do get a lot of dust in the blower chamber but the machine is only new with only a few hours on it. It's a standard Keens Puffer from Reeds. I'll have to set it up and take a look at the cloth but I think you are right. Even with regular dirt it only puffs when all the cloth is well covered.

 

[CreviceSucker]

Yes I do get a lot of dust in the blower chamber but the machine is only new with only a few hours on it. It's a standard Keens Puffer from Reeds. I'll have to set it up and take a look at the cloth but I think you are right. Even with regular dirt it only puffs when all the cloth is well covered.

which model do you have ?

I am thinking of getting the 151S deck because , if the blurb is truthful they claim that model has a new mat material that holds a higher static charge.

Or i could make my own...

any opinions on the static thing being valid especially on fine gold ?

I want to catch it ALL

 

[Nightjar]

Crevice Sucker,
The mention of static is purely a sales gimmick. We have trialed a Keene 151 alongside our home built bellows dry blowers, the bellows wins hands down.
Retreated fines from a 151 with the bellows and recovered fine mustard gold, put these same fines back through the 151 and lost all the fine gold.
If you "want to catch it all" invest in a bellows type dry blower.

 

[Nightjar]

Yes I do get a lot of dust in the blower chamber but the machine is only new with only a few hours on it. It's a standard Keens Puffer from Reeds. I'll have to set it up and take a look at the cloth but I think you are right. Even with regular dirt it only puffs when all the cloth is well covered.

MB, I'd be looking at fitting a tighter weaved cloth, you should not be getting a lot of dust in the chamber.
As mentioned you should see the cloth flexing slightly upside of riffles when running empty.
Back in the early days there was two types of cloth, one for bellows and one for the constant air, my guess your Keenes bellows is fitted with wrong cloth.

 

[Moneybox]

Yes I do get a lot of dust in the blower chamber but the machine is only new with only a few hours on it. It's a standard Keens Puffer from Reeds. I'll have to set it up and take a look at the cloth but I think you are right. Even with regular dirt it only puffs when all the cloth is well covered.

MB, I'd be looking at fitting a tighter weaved cloth, you should not be getting a lot of dust in the chamber.
As mentioned you should see the cloth flexing slightly upside of riffles when running empty.
Back in the early days there was two types of cloth, one for bellows and one for the constant air, my guess your Keenes bellows is fitted with wrong cloth.

Yes Peter that sounds right, the tray is most likely interchangeable with the blower machine. The kit could have just been put together selecting the wrong bits. I'll take a serious look at it. It rarely comes out of the trailer because it simply doesn't perform as expected. Right now I'm busy building a shade shelter for the bus then I have to be in Geraldton by midweek to have an airbag changed and Mrs M's hospital visit and then back by next Monday I expect with concrete for the holes. Then I can head off to Perth and Capel to put out a couple of fires. I've got a few too many to-do's at the moment.

 

[CreviceSucker]

Crevice Sucker,
The mention of static is purely a sales gimmick. We have trialed a Keene 151 alongside our home built bellows dry blowers, the bellows wins hands down.
Retreated fines from a 151 with the bellows and recovered fine mustard gold, put these same fines back through the 151 and lost all the fine gold.
If you "want to catch it all" invest in a bellows type dry blower.

Thankyou

I have a variable speed blower i could use but you feel the bellows still wins over a constant airflow ?

Your feeling is that efficient recovery comes down to cloth type and mesh size and bellows compression stroke and rate of pumping ?

Is the orbital shaker worth using to help classify the materials as they come down the box ?