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Gas Vac and new vortex separator


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I made the gas vac on the right several years back. I used a 4" abs pipe, standard toilet flange and a screw on lid. It works pretty well. Problem with running straight into the bucket below the motor is when it gets about half full it starts sucking rocks through the fan blades. So, I've been wanting to daisy chain buckets for a while. Wasn't real sure how to do it. Found this plastic Dust Stopper at Home Depot. Its plastic and I don't expect it to last long. It has given me a clear view at how to create one that's solid out of metal.

For now I opened it up and added some sheet metal that's bonded in place as a strike plate where the material hits first. Its bonded with a polymer modified cement based rubber my company makes. Then I coated the whole inner surface with the same material. For now it should get to see a couple trips, I hope.

As far as functionality and concept it seems to work excellent. I sucked up some sand and not a spec made it  into the bucket with the blower on it.

WIN_20181014_16_36_29_Pro.jpg

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I really like building things. Maybe I could have been an engineer if I'd stayed in school. One thing over the years that has been on my mind is what aussies call an "Opal Blower" I'd really love to reduce this down to a version that can sit above a drywasher. A leaf blower motor doesn't seem strong enough to power even a small version so for now I'll just consider my new daisy chain bucket good enough =)

12276850174_23891f9dd0_b-1024x683.jpg

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Jack, I like your contraption.  I ran across those bucket-top dust settlers on eBay, and have been thinking about building something similar to yours.  I haven't yet looked at one of the units up close and personal, and have been wondering about the plastic used, what kind of plastic, how thick it is.  I used to install new PTFE strips on a girlfriend's dog sled runners every year, and those little 1/4" strips of Teflon lasted for thousands of miles, sometimes being dragged across pavement while training, and over rocks and gravel in river beds, so some plastics can take a ton of abuse and impact and abrasion.  Maybe you'll get lucky and the thing will last way longer than you think it will.

Anyway, great idea for saving your vac fan from being destroyed by gravel.  

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10 hours ago, Jack H said:

I really like building things. Maybe I could have been an engineer if I'd stayed in school. One thing over the years that has been on my mind is what aussies call an "Opal Blower" I'd really love to reduce this down to a version that can sit above a drywasher. A leaf blower motor doesn't seem strong enough to power even a small version so for now I'll just consider my new daisy chain bucket good enough =)

12276850174_23891f9dd0_b-1024x683.jpg

For some of you that have never heard of an opal blower.

https://blackopaldirect.com/blog/opal-mining/

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Look at the Dayton high static blowers form Grainger. You can get a coated impeller for moving abrasive materials. They come in all sizes all the way up to "opal Blower" size. They are used to move all sorts of industrial materials, agricultural materials and food products. They use smaller ones on jumping balloons and noodle men at car lots. (Same thing but a much smaller impeller wheel). they use huge ones on vaccum trucks and vacuum excavators.

I use one with a 14" impeller and turn it with a 5 hp. gasoline engine. It will suck the dirt right out of the hole an move it several feet straight up with a 3" hose. I use 3" clear "food pipe" that will not erode when conveying abrasives. It is the same stuff you get for a shop dust collection system. It is clear, heavy vinyl tubing with a helical steel coil that keeps it from collapsing. Dredge suction hose is generally "food pipe". You can get scrap at any agricultural processing plant or just buy it online.

Instead of a vortex separator I use a series of buckets kinda like your outfit. The first is a ten gallon shop vac tub daisy chained into a five gallon with a dustless vacuum cleaner separator on top. The gold rarely passes the first bucket though. There is just fine dust and silt in #2.

I experimented with using just a hose on the downstream side. The "food pipe" has the same contour as "poopy tube" and it performs the same in a dry stream of air. Instead of catching my material in a bucket I just blew it out an exhaust tube about 10 feet long and most of the gold stays right there in the tube. I just dump the exhaust tube once in a while into a bucket. The airflow over the vibrating, corrugated pipe does a fine job at trapping the gold.

I call it my dry land dredge. It really sucks. It makes less noise than a leaf blower but produces a whole lot more airflow and has a bunch more static pressure. Instead of a helical vane impeller (like a leaf blower) designed for big CFM and air speed the impeller is a straight radial wheel designed for high static/pressure. Static pressure is what determines how much material is moved and how high it is lifted and not CFM or airspeed. So understanding the impeller design is very important.

You need a radial wheel, high static impeller designed for moving abrasives. It will have a plastic non-abrasive coating on an aluminum wheel. You can apply a thick urethane or plastic coating like tool handle dip or bed liner on a bare wheel and it will work fine. But you have to insure that you don't ruin the balance of the wheel when you coat it. A coated wheel made for moving sand and abrasives is just a few bucks more and comes already balanced.

I run my drywasher with the same blower. It is 4 stroke, quiet, and runs at about half speed with the drywasher so the engine lasts and lasts. This one blower outfit has lasted for many hundreds of hours of excavation and concentration. It does more than a leaf blower of any brand could ever do, lasts decades without problems, starts easily every time and uses no fuel mix. I got the engine new for about $125 and the blower and coated impeller cost about the same. So it does not break the bank and is professional grade mining equipment with a 100% duty rating. Leaf blowers are much more expensive in the long run if you plan on running them full time for days. They are just not designed for the duty rating that most serious operators put them through.

Just my two sheckles. I got sick and tired of wearing out leaf blowers and running out of air when a tired leaf blower would not reach peak RPM. I have been using this blower for a whole bunch of years and have never had one tiny issue with it. I really enjoy having enough vacuum and pressure to work with and not having that 2 stoke screaming in my ear all day.

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23 hours ago, Jack H said:

Sounds like an awesome setup Bob. Got any pics?

 

I don't have pics of the vac setup and the rig is broken down and stored. I will try to point a camera at it this afternoon so you can at least see the blower setup. 

It is just a 5 hp. Tecumseh vertical shaft engine mounted on a high static blower. Dayton 4c330.

Here are the specs for my blower. I cant believe how much the price has gone up. I think you could get one for a whole lot less. About $200 is what they should cost.

https://www.grainger.com/category/direct-drive-radial-blade-blowers/industrial-blowers-and-accessories/ventilation-equipment-and-supplies/hvac-and-refrigeration/ecatalog/N-ymf?searchRedirect=blower#nav=%2Fcategory%2Fdirect-drive-radial-blade-blowers%2Findustrial-blowers-and-accessories%2Fventilation-equipment-and-supplies%2Fhvac-and-refrigeration%2Fecatalog%2FN-ymfZ1yzgds9Z1z08owpZ1z0ku1b%3FsearchRedirect%3Dblower

 

Visualize this blower under a big lawn mower engine on legs.

Anyhoo, I will take a photo of my setup later this evening. 

 

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Here is the part that sucks. It will suck a hand, a grease rag or a small dog right in there. I keep that end caged off lest something gets pulled through the impeller.

It throttles off about 25% of the intake air but there is still plenty to do whatever I need to do at about 3/4 throttle. 

DSCN0448.JPG

 

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On 10/16/2018 at 11:36 AM, Bedrock Bob said:

Here is the air plant from two different angles. Check out my heavy duty coffee can coupling and laminated wood adapter plate! DSCN0444.JPG

 

DSCN0445.JPG

Hey Bob,

When it’s convenient, can you update or repost your photos for this? They don’t show up anymore on this post and I would love to see your setup. 

I researched the blower you mentioned, and there are some used units on Fleabay that are less expensive, but the photos look like there is no bearing holding the fan on- do these Dayton blowers come that way and depend on the motor shaft for the fan support?

C8A07F5C-60BE-467F-A1FD-A556E4F7088B.jpeg

Thanks!

-Anthony (I know what placers are :D )
 

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On 10/14/2018 at 4:58 PM, Jack H said:

I made the gas vac on the right several years back. I used a 4" abs pipe, standard toilet flange and a screw on lid. It works pretty well. Problem with running straight into the bucket below the motor is when it gets about half full it starts sucking rocks through the fan blades. So, I've been wanting to daisy chain buckets for a while. Wasn't real sure how to do it. Found this plastic Dust Stopper at Home Depot. Its plastic and I don't expect it to last long. It has given me a clear view at how to create one that's solid out of metal.

For now I opened it up and added some sheet metal that's bonded in place as a strike plate where the material hits first. Its bonded with a polymer modified cement based rubber my company makes. Then I coated the whole inner surface with the same material. For now it should get to see a couple trips, I hope.

As far as functionality and concept it seems to work excellent. I sucked up some sand and not a spec made it  into the bucket with the blower on it.

WIN_20181014_16_36_29_Pro.jpg

Jack, this setup worked very well for me recently, thanks for the idea!

-Anthony

 

D788F182-67AD-463F-BFDC-FAC2B8C0F1CE.jpeg

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1 hour ago, GotAU? said:

Hey Bob,

When it’s convenient, can you update or repost your photos for this? They don’t show up anymore on this post and I would love to see your setup. 

I researched the blower you mentioned, and there are some used units on Fleabay that are less expensive, but the photos look like there is no bearing holding the fan on- do these Dayton blowers come that way and depend on the motor shaft for the fan support?

C8A07F5C-60BE-467F-A1FD-A556E4F7088B.jpeg

Thanks!

-Anthony (I know what placers are :D )
 

On the direct drive blowers the impeller mounts directly to the shaft. You csn get various sized bores on the impeller to mount on whatever motor or engine you want.

They make blowers with a shaft and bearings. You can mount a pulley and run a belt down to your motor r engine.

Mine is a direct drive on a Tecumseh 5hp. Lawn mower engine. I welded a frame and some feet so it sits 4" off the ground. I put some expanded metal over the intake and set the whole thing on plywood so it does not suck up gravel from the bottom.

I'll take a photo soon. The equipment is deep under a pile of stuff and I plan on digging it out in a week or two.  But it is simple.

The only trick was getting the blower centered in the housing. I had to make an adapter to go between the engine and the blower chassis that was the right thickness. I used a chunk of plywood stacked to just the right thickness with holes drilled to run the bolts through.

It will blow more than enough air for a huge drywasher. You could get by with a lot smaller blower and a lighter engine for most operations.

I built two horizontal shaft blowers with 3.5 h.p. Briggs. They are designed for an electric motor so I had to modify the blower chassis a little for the taller gasoline engine. But they worked great.

The best blower ever was a 9" high static blower with a 3/4hp electric motor. Direct drive. I ran it off a generator in the truck and ran a cord to it. It was quiet and absolutely bullet proof. And it made using an electric vac easy. You just had to get the truck in close to the diggings. But the all electric setup was by far the best and easiest blower unit I have built.

If you have several tons of material to run it makes sense to use a generator. But if you are working various spots that are hard to get a truck close to the lawn mower engine on a high static blower is awesome. You just have to buy plenty of good hose and get it as far from the dust as you can.

I use heavy duty vinyl food pipe or heavy industrial conveyance pipe. Like they use in agriculture to move grain and fibers. I generally use 20 feet of the stuff unless the wind is really howling and taking the dust away. 

You are always crushing the pipe and burying it in tailings. Or dragging it through horny bushes. So I always use the good stuff. Otherwise you spend more time patching hose with duct tape than concentrating gravel. 

I only use the blower if I am on a big pile of gravel. If I have several yards that I know has good gold I will use it. Otherwise I generally use the hand crank for sweeping and working along bedrock. 

Hope that helps. If there is something you would like me to elaborate on just ask. And I will post some more pics one of these days soon. I might even have those pics on the hard disk somewhere. If I locate them I'll post them here.

Bob

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22 hours ago, Bedrock Bob said:

On the direct drive blowers the impeller mounts directly to the shaft. You csn get various sized bores on the impeller to mount on whatever motor or engine you want.

They make blowers with a shaft and bearings. You can mount a pulley and run a belt down to your motor r engine.

Mine is a direct drive on a Tecumseh 5hp. Lawn mower engine. I welded a frame and some feet so it sits 4" off the ground. I put some expanded metal over the intake and set the whole thing on plywood so it does not suck up gravel from the bottom.

I'll take a photo soon. The equipment is deep under a pile of stuff and I plan on digging it out in a week or two.  But it is simple.

The only trick was getting the blower centered in the housing. I had to make an adapter to go between the engine and the blower chassis that was the right thickness. I used a chunk of plywood stacked to just the right thickness with holes drilled to run the bolts through.

It will blow more than enough air for a huge drywasher. You could get by with a lot smaller blower and a lighter engine for most operations.

I built two horizontal shaft blowers with 3.5 h.p. Briggs. They are designed for an electric motor so I had to modify the blower chassis a little for the taller gasoline engine. But they worked great.

The best blower ever was a 9" high static blower with a 3/4hp electric motor. Direct drive. I ran it off a generator in the truck and ran a cord to it. It was quiet and absolutely bullet proof. And it made using an electric vac easy. You just had to get the truck in close to the diggings. But the all electric setup was by far the best and easiest blower unit I have built.

If you have several tons of material to run it makes sense to use a generator. But if you are working various spots that are hard to get a truck close to the lawn mower engine on a high static blower is awesome. You just have to buy plenty of good hose and get it as far from the dust as you can.

I use heavy duty vinyl food pipe or heavy industrial conveyance pipe. Like they use in agriculture to move grain and fibers. I generally use 20 feet of the stuff unless the wind is really howling and taking the dust away. 

You are always crushing the pipe and burying it in tailings. Or dragging it through horny bushes. So I always use the good stuff. Otherwise you spend more time patching hose with duct tape than concentrating gravel. 

I only use the blower if I am on a big pile of gravel. If I have several yards that I know has good gold I will use it. Otherwise I generally use the hand crank for sweeping and working along bedrock. 

Hope that helps. If there is something you would like me to elaborate on just ask. And I will post some more pics one of these days soon. I might even have those pics on the hard disk somewhere. If I locate them I'll post them here.

Bob

Hi Bob,

Hope Jack doesn’t mind this extention on his post about vacuums, but it’s all good info for readers too.  Thanks for the detailed description of your setup.  I have a 3/4 hp 4-stroke horizontal Honda engine that could be used to run a horizontal shaft blower with a pulley, thanks for that idea!  

Are you using a dust collection (vortex filter) of any type?  As Jack mentioned above, and as I’ve recently tried out, the plastic one from HD works well for small jobs, but I was also looking for a higher volume metal one if I build a higher airflow blower based vacuum.  Most of the metal ones I found are funnel shaped and rather tall, making the collection barrel rather cumbersome, I would guess.  If you use these, what is yours based on?

last question- what was the hand crank for? Shoveling or something hand cranked?

Thanks for your help, appreciate it!

-Anthony

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A Hand cranked drywasher. As opposed to a blown air drywasher. 

I don't use a vortex separator. When I use a vacuum I take off the filter and let whatever blows by just go. All the gold stays in the bucket. You can even just put a helical coil hose downstream instead of a bucket. The gold gets trapped in the hose and the rest blows by. It concentrates good with no bucket at all. You might loose a few tiny pieces but it saves a whole bunch of running dirt. 

 

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Interesting- yeah, I noticed stuff getting stuck in my hoses and wondered how much of it was gold.  I just found a Billygoat 5hp gas blower on wheels for cheap, may be looking at how to modify it for vacuuming. 

Would like to see your pics whenever you get to them, thanks for the great ideas!

-Anthony

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I found some photos on the hard drive. I think the are the same ones I posted on this thread long ago.

Here is the blower from two sides. You can see the little welded frame and plywood base. And the duct adapter I made from a coffee can. Check out the plywood adapter. It is just the right thickness so the blower impeller rides in the blower housing. The throttle control is just a lawn mower throttle with a shortened control cable. Simple stuff. 

That hose is heavy duty dust collection hose. It is not as tough as food pipe but it is good. You can step on it and it comes back in shape pretty good. It will tear but not too easy. Duct tape will fix it good. If you are careful it will last for a long time. 

DSCN0444.JPG

DSCN0446.JPG

The third photo is the intake, or vacuum side. If you get your hand in there you will draw back a stump. And it will suck it right in there too.

DSCN0447.JPG

This unit is too big to drag around on a bucket. You can tap the vacuum side and duct it into a bucket lid or shop vac tank. You are limited in range though.

I don't vacuum much anymore. I blow. With a bellows or a blower. Blow it clean after raking. Then sweep and speck up the gold. It is easier to work remote areas like that and you don't have to have a bunch of equipment. Not even a drywasher. I use the big blower drywasher on big piles and larger expanses of gravel. So this equipment is not really engineered to be a good vacuum.

But...

The horizontal shaft blower with a wheel engineered to convey abrasives will suck it up like a dry dredge and blow it right down a section of helical pipe and into a bucket. Or just out on the tailings pile. It wont suck it uphill very far. But it will move it 10-15 feet away from the diggings. And most of the gold will stay in the pipe and never get close to the end of the hose.  Still, you see most of the gold as you are sucking it up. The nuggets will lag behind while everything else gets sucked into the pipe. So will the fine gold if you suck it up gradually and use a broom to help the gravel along.

That is when I started blowing the material away from bedrock rather than trying to collect it. I saw the vacuum sucking up all the waste and the gold staying behind. I was concentrating the gravel with the vacuum just sucking it up. So I decided to blow instead of suck. I didn't need to handle the material and concentrate it any more. Just blow it in whatever direction I wanted. What is left on the bedrock is concentrates that can easily be swept up or vacuumed into a bucket. 

If you blow it away slowly and use a broom to loosen the gravel you don't loose much. Even piles of dirt that have been shoveled out of a hole can be concentrated with an air stream faster than running through a dry concentrator. I honestly don't think that the loss offsets the benefits of shoveling it all up, vacuuming and then running it through a machine unless you are in a real hotspot with lots of fine gold. In the area I generally work 90% of the gold is freckle size and above and blowing is the very best method of concentrating bedrock. Even using a small bellows and a garden rake you can tell pretty fast if the area is worth working. 

So there is my two bits on blowers and suckers. Hope it got you to thinking.

 

Bob

 

 

DSCN0445.JPG

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2 hours ago, Bedrock Bob said:

I found some photos on the hard drive. I think the are the same ones I posted on this thread long ago.

Here is the blower from two sides. You can see the little welded frame and plywood base. And the duct adapter I made from a coffee can. Check out the plywood adapter. It is just the right thickness so the blower impeller rides in the blower housing. The throttle control is just a lawn mower throttle with a shortened control cable. Simple stuff. 

That hose is heavy duty dust collection hose. It is not as tough as food pipe but it is good. You can step on it and it comes back in shape pretty good. It will tear but not too easy. Duct tape will fix it good. If you are careful it will last for a long time. 

DSCN0444.JPG

DSCN0446.JPG

The third photo is the intake, or vacuum side. If you get your hand in there you will draw back a stump. And it will suck it right in there too.

DSCN0447.JPG

This unit is too big to drag around on a bucket. You can tap the vacuum side and duct it into a bucket lid or shop vac tank. You are limited in range though.

I don't vacuum much anymore. I blow. With a bellows or a blower. Blow it clean after raking. Then sweep and speck up the gold. It is easier to work remote areas like that and you don't have to have a bunch of equipment. Not even a drywasher. I use the big blower drywasher on big piles and larger expanses of gravel. So this equipment is not really engineered to be a good vacuum.

But...

The horizontal shaft blower with a wheel engineered to convey abrasives will suck it up like a dry dredge and blow it right down a section of helical pipe and into a bucket. Or just out on the tailings pile. It wont suck it uphill very far. But it will move it 10-15 feet away from the diggings. And most of the gold will stay in the pipe and never get close to the end of the hose.  Still, you see most of the gold as you are sucking it up. The nuggets will lag behind while everything else gets sucked into the pipe. So will the fine gold if you suck it up gradually and use a broom to help the gravel along.

That is when I started blowing the material away from bedrock rather than trying to collect it. I saw the vacuum sucking up all the waste and the gold staying behind. I was concentrating the gravel with the vacuum just sucking it up. So I decided to blow instead of suck. I didn't need to handle the material and concentrate it any more. Just blow it in whatever direction I wanted. What is left on the bedrock is concentrates that can easily be swept up or vacuumed into a bucket. 

If you blow it away slowly and use a broom to loosen the gravel you don't loose much. Even piles of dirt that have been shoveled out of a hole can be concentrated with an air stream faster than running through a dry concentrator. I honestly don't think that the loss offsets the benefits of shoveling it all up, vacuuming and then running it through a machine unless you are in a real hotspot with lots of fine gold. In the area I generally work 90% of the gold is freckle size and above and blowing is the very best method of concentrating bedrock. Even using a small bellows and a garden rake you can tell pretty fast if the area is worth working. 

So there is my two bits on blowers and suckers. Hope it got you to thinking.

 

Bob

 

 

DSCN0445.JPG

Very interesting... the process must be really dusty, but I can see where you’d be cleaning up pretty well.  Drywashing is a smaller, more intensive way of doing what you are doing, and I bet your yield to effort ratio is a lot higher. That unit could easily be put on top of a metal wash tub to turn it into a vacuum too, I like your design, and thanks for pulling those photos out, I appreciate it!

Edited by GotAU?
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22 hours ago, GotAU? said:

Very interesting... the process must be really dusty, but I can see where you’d be cleaning up pretty well.  Drywashing is a smaller, more intensive way of doing what you are doing, and I bet your yield to effort ratio is a lot higher. That unit could easily be put on top of a metal wash tub to turn it into a vacuum too, I like your design, and thanks for pulling those photos out, I appreciate it!

Hey Bob, I just got 4.6hp 4-stroke mounted to a Dayton hp blower.  It was for commercial big jumpers, now I have a fun weekend mod project to work on.

I will definitely use your ideas to set up the vacuum and pressure side of it, and will use Jack’s idea for the vortex separator.  Thanks again for your help!

BA9ADB63-C02A-4D5E-ADAF-5FB64EE744E4.jpeg

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