Materials for dryblower

Hey guys, I'm going to build a dryblower, and was looking at how important the static charge is.
For those that have built or used one can you relay how important selecting opposing charged materials actually is.
If you look here http://www.school-for-champions.com/science/static_materials.htm#.WHBaHfl96Uk
Gold holds a negative charge, steel neutral, aluminum slightly positive, leather and fur much more positive.
So what would be a good way to hold a charge in the riffle box and not have it go to ground?
Even though they don't hold it would steel legs not transfer static?
Would lining the lower section of the riffle box with leather help at all? I mean the lower air box, not the actual riffle tray.
Cheers Mark

Have a look at the new keene.
They have a fine plastic or fiberglass gasket that holds the charge.

Thanks.
Just another idea, would a computer fan with some rabbit fur attached on the back, then positioned just under the riffle tray. Supply it with power, theoretically it should charge the tray with positive static, promoting gold that is negative to stay in the tray better???

I don't understand static well. How is it possible to isolate the riffle tray so the built up charge doesn't dissipate to the ground?

OK looks like having a wood stand with a plastic feeder and riffle tray would be a good idea.
I can't get a one piece feeder/riffle box made obviously. So that leads me to think of plastic welding. Does anyone know how that would hold up to the punishment of vibrations etc?

My brother use to do plastic welding on car bumpers.
They hold up fine on a car and vibrations.

Thanks Kane, I'm just wondering if I'm overthinking it, and if the effort to hold static charge is actually a big advantage?
If it was 20% then hell yeah, but if it's only 2-5% then the overall gain would be minimal and I may as well make it out of aluminium.

Occasional_panner said:

Thanks Kane, I'm just wondering if I'm overthinking it, and if the effort to hold static charge is actually a big advantage?
If it was 20% then hell yeah, but if it's only 2-5% then the overall gain would be minimal and I may as well make it out of aluminium.

Click to expand...

I don't think investigation would be wasted .

Nylon , polyester or other fibre may improve static.

You might reach a point where it becomes too high so too much dirt is stuck to the screen but it won't hurt to try and improve fine gold catch rates ?

Keene has probably experimented too but why not put some thought into it yourself as well ?

It's not the same material types but I experienced an event recently on a sandblaster I built , where fine copper slag particles getting sucked up an aluminium tube created enough static charge to give me a zap around 3 times stronger than an electrified cattle fence , a little higher and it could kill a person .

Build a puffer dryblower out of steel, forget about the plastic, rabbit fur etc some one will be suggesting womens knickers next.
This little one catches the mustard.

Have you got more pics of that blower Nightjar? Particularly the bellows mechanism/cam link etc?

Hey OP, I would go the same way as Nightjar. They say the static helps but in all honesty I think I have never read how much of an advantage it is. I manage to hang on to the fines in my Dry Blower ok anyway. I'm pretty sure Bellows and fan operated/vibrating Dry blowers operate on slightly different principles, that is the bellows type is not necessarily utilising the vibrostatic principle. When making mine I never gave the vibrostatic stuff a thought, I just made a fan with counterbalance so it made the riffle box shake...and it does....and it hangs on to fine gold. I would not overthink it too much.

Cheers,
Matt

Hi OC
Nightjar,will point you in the right direction,he goes way back on dryblowers,angle of the tray, what materials,he has been there and done it,he has spent a lot time fiddling to get them to function as best you can.
I my self have a battery keene puffer,25mts away you do not hear it working,all day with a old battery,and at the end of the day you do not go home deaf,and not as dusty as the blower types.
The other thing is you do not rubber necks turning up to see what you are doing.

Yes Digger, that does look like a nice compact unit.
I'll make the frame like MJB and make two lower boxes, I know if my wife is coming she will hate an engine running.
So one bellows type and one constant air shaker type.
I have a spare blower and it's the type that draws heat from the cyl head into the fan, it also runs exhaust into it too, but that's easy to re route. I did think of running the exhaust down the throat of the blower tube and back out the side before the flex pipe fits on, a bit like a heat exchanger. That way the sticky exhaust won't foul up the cloth. A bit of baffling around the cyl to draw more heat in the intake would be fairly simple, similar to how you cool small airplane engines.

What MJB said, dont over think it to much mate.. If you look up some of the patents through google on keenes designs and similar you'll get the jist of it. Vibration/shaker fan in mine catches pretty much everything.

Thanks guys, I reckon you are right, just keep it to a proven format. I can and will play around with static devices down the track.
I'll work on making the fan/vibrator first as it appears to be the most complicated part of the constant air feed system.
Reckon I'll build the bellows type second.

The fans are actually quite easy to make. I used a couple of bearings out of an old drill. Few washers, a bolt, couple of nyloc nuts, drilled and tapped a small collar for a bolt to screw in with counterweights on the end....I'll try get a couple pics of mine today..

Heres a few fans made from other members for some more ideas ..
https://www.prospectingaustralia.com/forum/viewtopic.php?id=8979
https://www.prospectingaustralia.com/forum/viewtopic.php?id=5425

Or, you can buy them pre made ... http://www.goldrushtradingpost.com/inc/sdetail/drywasher_counterweight_fan_assembly/4752

My Opinion
The "Static charge" thing is a gimic to sell more dry blowers, don't forget Keene are in the business of relieving prospectors of their hard earned money.
The bellows type Dry Blower in my opinion is the optimum type, think about the operation "Agitate - Settle - Agitate - Settle" this is how the basic Gold pan is operated, it is also how a Jig operates !!!! the constant Blow provides too much constant movement, how on earth can a Static charge hold a gold particle with all the other material flowing over it ?????
cheers
Lee

Well it would be interesting if someone got 1 cubic metre of dirt and ran it through the new 140s and then mixed up all the tailings and cons and re ran that material with the box grounded to the earth to remove static.
Then you would see if it worked.
Thanks Ballarat Gold for the fan links.
I was going to try and copy the newer one from keene
The new one has a weight top and bottom with a shroud attached to the fans perimeter.

If you understand the basic concept of the 'shaker fan', then anythings a goer mate.

Well I did a backflip and decided to make a bellows style first. I got a wiper motor from a sv21 camry, it's a nice big solid one compared to other models.
I ran it on full for 10 min and it got pretty hot, then I used a speed controller and ran it at half speed, and it seemed to get even hotter. (I did rest it and cooled it for 30 min between tests) Anyway it gets too hot to touch, not scorching but you wouldn't want to keep your hand on it, this would seem like something that could fail.
Is it normal for them to run this hot?
I opened it up, it has three brushes the two opposing ones have the wires connected and the third is connected via what looks like a rectangular capacitor.
The other two wires are connected to the housing.




This is the type of controller I used http://www.ebay.com.au/itm/12V-24V-...935243?hash=item419a6131cb:g:5nAAAOSw~gRVvEE0

BTW it spins freely with the magnets removed, so doesn't look like drag is an issue.

Hi OP
That does not seem right,my motor does not run that hot.
My motor only has 2 wires to it,with speed control,look up google and check wiring diagram.