Gravity dredge info/thoughts

[AugustMoose87]

So from what I have been able to gather, a gravity dredge is a siphon, correct?

And from what I have seen, most guys are looking for a 6'-10' drop over 100' or less. What is more critical - length, slope? Like could you get away with 1' drop over 10' instead of 10' over 100', or would you be better off only getting 6' drop over 100', but having that full 100'?? My intuition is telling me slope (because a 1' drop over 1' should do better than a 1' drop over 10').

And finally, my stupid question... has anyone ever tried this with a garden hose?? I don't have any areas I really NEED a dredge, but while I am waiting for "Santa" to bring me a Gold-n-Sand, I'm thinking I might be able to get by with a section of garden hose. I realize the diameter would be a bit restrictive compared to the 3"-4" hoses most people use, but it would also be a LOT more portable. Plus most of the areas I have been working have pretty fine gold...

 

[russau]

the more drop and the bigger diameter pipe means more pressure and eventually more suction. a garden size hose would really be a waste of time.

 

[2cmorau]

fer $20 u not only support this site, but will let ya do advance search, upper right hand corner. and fur a mis'ly 35 greenbacks you can help support the cuz PLP1.org so we all can use a motorized version
http://www.treasurenet.com/forums/gold-prospecting/433395-8-inch-gravity-sluicing.html
http://www.treasurenet.com/forums/dredging-hi-banking/178510-gravity-dredges-allowed-california.html
http://www.treasurenet.com/forums/g...aterial-out-moving-stream-without-dredge.html

 

[Goldwasher]

2 inches and bigger or your wasting time. Rock jams and plug ups are gonna be an issue. You can't bang on pipe to clear jams like you can on dredge hose.

 

[Aufisher]

Go big or go home!

 

[NeoTokyo]

Home depot has corrugated pipe in 50' and 100' lengths up to 4" for under $60 dollars.
They also have all the neat fittings to make your own dredge nozzle in the same area (Surprisingly.)

Its a sluicebox and dredge hose all in one.

If you are really worried about gold getting out at the end you can put a sluice at the end, but I highly doubt that anything will show up unless your passing massive amounts of heavies through and cementing those ribs up.

That is going to be your best bet for going cheap and effective.

 

[NeoTokyo]

 

[AugustMoose87]

I don't know why I never thought of the fact that corrugated pipe would act as a sluice... I should have, since I'm always looking for drainage pipes to clean out... That opens a bunch of spots, only having to carry that in, no xluice or anything.... Thanks!!

 

[ConceptualizedNetherlandr]

Home depot has corrugated pipe in 50' and 100' lengths up to 4" for under $60 dollars.
They also have all the neat fittings to make your own dredge nozzle in the same area (Surprisingly.)

Its a sluicebox and dredge hose all in one.

If you are really worried about gold getting out at the end you can put a sluice at the end, but I highly doubt that anything will show up unless your passing massive amounts of heavies through and cementing those ribs up.

That is going to be your best bet for going cheap and effective.

Must be a chore to haul out a 100 foot 4" corrugated hose laden with gold

 

[NeoTokyo]

Oh yeah, its a big ass bundle.
Tightly rolled like it left from the factory its still a tight fit for most truck beds.

You really need to use a backpack frame when hauling something like this around, otherwise its a lot more work than expected.
Its also a real PITA for tight woods hiking.

If size is a real problem then you can split it into two sections and hike one in, and then the other and use a coupler to join them back together, which is of course sold at Lowes or Home Depot.

 

[MinerFortyNiner1952]

We used a 2.5" hose with a nozzle that had a bar welded across the tip to reduce the size of rocks it could suck in. This helped to eliminate jams
and surprisingly had really good suction. It was 100 feet in length and we probably had about 10-12 feet in elevation drop.

 

[NuggetN8]

Don't use the corrugated stuff.. It doesn't get nearly as much suction as normal dredge hose and it gets holes in it very easily. Mine had a million pin hole leaks in it the second day of use. Not very good for a lot of pressure and rocks flying through it. I have 2 setups that I use 65' of 2" and 50' of 3". I only use them in small steep creeks that usually have a lot of drop though. If your going for river dredging you'll need quite a bit more unless it's an area with a good amount of drop. With normal dredge hose 6ft or more of drop is plenty to make it work decent. I don't need much because the creeks I work don't have a lot of water flow so too much is actually a bad thing. I've dredged a hole where there was a ton of drop maybe 15ft or so and i sucked it dry in seconds.. Restarting a gravity dredge can be a real pain. Have to replug the end and fill it and make sure most of the air is out of it before unplugging it. I would also suggest making some kind of weight to strap around the intake so it stays underwater while you don't have it in hand to save you a lot of time consuming refills. I mostly only use my setups for final cleanup rather than moving a lot of material in smaller creeks. Sluice it then really get down in there and make sure everything is clean by gravity dredging. You can use any size of hose that you want to siphon but 2" is the smallest I would ever go. And even with a 2" you need something slightly smaller for the intake. Some would say that size wouldn't be worth it but it depends on how you work and how much water you have to work with. The 3" is a monster when it comes to moving material with sufficient drop but takes quite a bit more water flow. Length and slope are very important but it depends on what the area is like where you want to use it. As long as you have the required amount of drop within the length of hose that you have you're golden. Never tried a garden hose before but it should work. May be a waste of money because it could plug and you'd never be able to unplug it since you can't see where it's plugged. Here's my crappy gravity dredging video I took a while back.. Was with the 2" with not very much drop in shallow water. If there were water where I go right now I'd remake it with the 3" but that will have to wait.

 

[H-2 CHARLIE]

7 yrs to replenish the river bottoms / ripe pickings

 

[Hoser John]

Never seen a river or creek replenish in 7 years. Must have massive landslides, major floods,multiple tree falls,roads built or the banks ripped up righteously. Then that huge quanity of materials takes years to concentrate down and stratify into a viable paystreak. In nature for every rule a thumb there are a miniscule number of exceptions but in 57 years of constant mining I've never seen a single example without the major ramifications that predicate a massive influx of materials. Still looking a half dozen times this past few weeks and now WATER YAHOO-John

 

[NuggetN8]

Never seen a river or creek replenish in 7 years. Must have massive landslides, major floods,multiple tree falls,roads built or the banks ripped up righteously. Then that huge quanity of materials takes years to concentrate down and stratify into a viable paystreak. In nature for every rule a thumb there are a miniscule number of exceptions but in 57 years of constant mining I've never seen a single example without the major ramifications that predicate a massive influx of materials. Still looking a half dozen times this past few weeks and now WATER YAHOO-John

Going to have too agree with Hoser on this one. A little bit of flood gold may have replenished but most likely nothing substantial. The only thing I've seen "replenish" in the areas I work was when banks wash out during huge storms. But even then it's technically not replenishing because the gold was already sitting there. Just opens up new spots to work that weren't visible before.

 

[BurntBear]

Awesome stuff!