Placer Claim Mined Out?

[desertgolddigger]

I belong to a local club that owns a claim. This club has had this claim for many years, and acquired it after the old timers had mined it previously, and others after they commercial outfits closed up.
I walked quite a bit of the 160 acre claim, and noted that just about every wash had been worked. Most of the surface nuggets has also been detected by those with gold detectors. In other words, this place has been picked over and over and over.
But I m a stubborn type of person, and I figured, just watching how people ram their puffer and blower drywashers, that some gold was just being blown through them. maybe not much, but some small stuff that never got a chance to settle behind the riffles.
I know many of you would never go to the effort of digging for three to four hours through the tailings in these washes. Again, I'm a bit stubborn, and anyway, I just wanted to have some fun locally, instead of driving 300 miles roundtrip to something that gives a little more for less effort.
I've spent the last three weeks, digging a few times a week along about 30 yards of wash, and have recovered just about a gram of gold. That might not seem like much, but I have only dug up 5 grams, not counting this one gram in almost 20 years out here drywashing in the desert of southern California.
As you would know, things always seem to go wrong. My gas powered blower motor decided it was time for the repair shop, and haven't heard from the shop in two weeks. So I purchased a WORX WG521 corded electric leaf blower to use with my Royal Large drywasher. I'm using a portable generator to provide the power. And it actually is working better than with my old gas powered blower. I have to run the blower on the lowest speed, or I just blow everything through the riffles. Results are very good, as I am getting gold specks so small that I will have to use the Blue bowl in order to recover them.
I'm not only getting a little gold, I'm having some fun, and I am getting a good workout. I've lost 10 pounds since I started. So things are going well.
I'm still digging test holes around the old time hard rock mines in the hope I will find where the gold has drifted downhill below these mines. So far just a couple specks here and there. I figure I just have to move laterally one way or the other before I get something better Of course, I' don't really know if the old timers stripped the hillsides. Even if they have, they apparently aren't as thorough as I am. I hope that I may be lucky and find a larger piece of gold that the old timers, previous placer miners, and detectorists have missed.
Hope everyone is having as much fun as I have been having.

 

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[desertgolddigger]

nice work, Caley! Bear in mind that if you want all the grooves to have the same depth at the feed end, each groove will be at a different angle, because of the length differences. I just bought a rare tablesaw made by Delta, that allows the radial arm to be rotated to be in line with the table. It should make cutting the grooves really easy, once the right jigs are made for all the angles.
Jim

Jim, I guess my jig will be useless then. I'd planned to have the outfeed end at zero depth, of course, which means the infeed ends would vary slightly. I've no way to make ten sets of jigs.

I'm wondering if you, a metal worker, might be able to take two long strips of metal that would take the weight of a router, and drill/tap holes in each end. Then you'd have something you could control the depth from zero, to whatever depth needed along its length, based on how long a groove you needed.

I probably could do this with pieces of square hardwood dowels, but anchor just one end, and shim the required depth at whatever point needed.

Just an idea for permanent jigs. You'd still need two to support the router, and a piece of hardwood for the router guide fence.

Once you get the riffles routed into the wood, then it's easy to seal the wood, then paint whatever color you want.

EDITED: My local ace desert hardware store carries 1/8 x 1/2 x72 inch low carbon steel strip stock. I think I'll go see how stiff 36 inches is. I may just need to cut it in half and tape one end down, and shim the other, on both for a router bridge. This would be a lot easier then the wood I'm using.

 

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[Jim in Idaho]

Caley, the easiest way to do what you want to do is shim the table to the various angles needed, and run the router over it flat, letting the table angle handle the tapers for each groove. What you have to do to determine the angle for each groove is take the length of the groove, and the difference in depth. You divide the depth at the feed end by the groove length. Say the groove is 12" long and you want it 1/4" deep at the feed end. Divide 1/4 by 12 and you get .020833. That's the ratio of the length to the depth. Now let's say you're going to support the tab while you rout, at the feed end, and your table is 26" long. Multiply the 26" x the ratio, which is .020833. That gives .5416". That's the shim thicknes you need under the feed end of the table to put the table at the correct angle for cutting THAT groove. You have to repeat this process for each groove as their length changes. Sounds WAY more difficult than it actually is. You just need a $15 pocket calculator....doesn't even need to do angles. . Remember, if you get off a bit, it's not world ending. You're making a shaker table.....not a Lunar Lander. (Go Air Force....LOL) If you're putting the grooves at an angle to the table motion, you'll have to angle either the router pass, or angle the table sideways, too. Also remember if your shims aren't precise to 100/s of an inch, the gold won't care. You'll just end up with slightly longer or shorter grooves than you planned, so don't sweat it. A cheap pair of dial or digital calipers would be your friend in this.
Jim

 

[Jim in Idaho]

Jim, I guess my jig will be useless then. I'd planned to have the outfeed end at zero depth, of course, which means the infeed ends would vary slightly. I've no way to make ten sets of jigs.

I'm wondering if you, a metal worker, might be able to take two long strips of metal that would take the weight of a router, and drill/tap holes in each end. Then you'd have something you could control the depth from zero, to whatever depth needed along its length, based on how long a groove you needed.

I probably could do this with pieces of square hardwood dowels, but anchor just one end, and shim the required depth at whatever point needed.

Just an idea for permanent jigs. You'd still need two to support the router, and a piece of hardwood for the router guide fence.

Once you get the riffles routed into the wood, then it's easy to seal the wood, then paint whatever color you want.

EDITED: My local ace desert hardware store carries 1/8 x 1/2 x72 inch low carbon steel strip stock. I think I'll go see how stiff 36 inches is. I may just need to cut it in half and tape one end down, and shim the other, on both for a router bridge. This would be a lot easier then the wood I'm using.

 

[Jim in Idaho]

Well, crapola. Chris and I spent the last two days traveling south to Tecopa, Ca., only to have the weather forecast change from a day or so of rain, and then 10 days of clear, to 5 or 6 days of rain starting tomorrow night. and not sure after that. So, we'll get some work done on the prospect tomorrow, and then do what we can during the bad weather while waiting for the sun again. The only good thing is at home it's going to be below freezing and snowing for the same period of time. I won't miss that..guaranteed...LOL
Jim

 

[russau]

I've got a idea for a jig for your router to cut tapered rows on your table. I got this idea from a woodworking project that I'm working on.. To start off have your material that you want to use for your table cut square to your shape you want. Then draw out your design on this slab of material .I wanted to use UHMW plastic but you could use anything. Make a jig(or have someone in a machine shop) to hold your router that will stretch across the tables width and be guided by the tables squared off edges . This material is to be cut on a taper from one side to the other and it'll be attached to the two 9 inch long pieces that will be the guide to keep your jig square to the edge .Now this will consist of 2 pieces of material the width of the table and 2 pieces of the same material but are about 9 inch's long and they will be connected to the other 2 piece's of material that stretch's across the width of the table. This will form the jig for your router to slide on as it is cutting the tapered grooves . Now to keep the tapered lines straight in a row you'll need to know the distance of the spacing for the taped rows that your fine gold will travel.. This will need a centering hole drilled on both sides of the table that will allow the jig to be moved after each cut from the router and these rows will need to follow or stop at your design that you already drew on the table. you can adjust the table's slant as you need it . I hope this spurs some thought's along the lines your thinking. what do you think ?? I wanted to make this for me awhile back but in a 2 x4 or so size

 

[southfork]

Just cut the grooves the same depth to the length needed then ramp the ends. It could be done with a plunge router or a file. I used a piece of 1"x 2" clamped as a guide and a worm drive saw. It would be nice to know someone with a CNC Router and let the computer cut the grooves. To add to this I was going to use door shims or a couple of cedar shingles as guides on the end of each groove after I cut all the grooves to ramp. Just ramp one at a time the shims go from paper thin to a 1/4 inch or more.

 

[Assembler]

Just cut the grooves the same depth to the length needed then ramp the ends. It could be done with a plunge router or a file. I used a piece of 1"x 2" clamped as a guide and a worm drive saw. It would be nice to know someone with a CNC Router and let the computer cut the grooves. To add to this I was going to use door shims or a couple of cedar shingles as guides on the end of each groove after I cut all the grooves to ramp. Just ramp one at a time the shims go from paper thin to a 1/4 inch or more.

Good idea there.
How about the last 1/3 or so of the grooves recut a little deeper with the ramp at the ends also cut.
My two cents here.

I like the idea of the door or cedar shim use for the ramp ends.

 

[desertgolddigger]

Guys, Thanks so much for all the suggestions. I think my own pea brain came up with a viable way to cut sloped grooves.

I went to Ace Desert Hardware, and saw the alternative, which is aluminum angle. This will eliminate the need for a fence. The two aluminum angles will keep the router going straight also..

Ill have to find out the diameter of my router base to set the two angles the proper distance. I just tape the ends of the aluminum angles down to the end of the board, and shim the other end, putting a piece of 1/4 inch under the angle at the point I want the router to exit. Once the high end of the angles are set, I just tape them in place for each cut.

Very simple. Just set the router bit depth, and run it up the incline.

 

[southfork]

Guys, Thanks so much for all the suggestions. I think my own pea brain came up with a viable way to cut sloped grooves.

I went to Ace Desert Hardware, and saw the alternative, which is aluminum angle. This will eliminate the need for a fence. The two aluminum angles will keep the router going straight also..

Ill have to find out the diameter of my router base to set the two angles the proper distance. I just tape the ends of the aluminum angles down to the end of the board, and shim the other end, putting a piece of 1/4 inch under the angle at the point I want the router to exit. Once the high end of the angles are set, I just tape them in place for each cut.

Very simple. Just set the router bit depth, and run it up the incline.

Clamps will work way better than tape if the tape fails you will end up with a snake.

 

[desertgolddigger]

Clamps will work way better than tape if the tape fails you will end up with a snake.

Yes, I already thought of clamps. Though the tape I would've used nis carpet tape, which I've found is nearly impossible for me to pull off, once attached to something.

I'm in the process of building this router track. It's 36 inches long, so plenty long for my needs.

I cut some 1/16 aluminum sheet to first, super glue on the aluminum angles to get the desired width. I'm waiting a few hours for that to cure up. Then I'll drill four holes through these aluminum cross pieces and through the aluminum angles for each end. Then I'll screw everything together.

That'll leave 30 inches of workable space for my router. Since I'm just doing an experimental 15x24 inch table, that should work. Whenever I decide to build a large table, I'll have to get longer angle, probably six feet long, and heavier gauge.

 

[desertgolddigger]

Well, crapola. Chris and I spent the last two days traveling south to Tecopa, Ca., only to have the weather forecast change from a day or so of rain, and then 10 days of clear, to 5 or 6 days of rain starting tomorrow night. and not sure after that. So, we'll get some work done on the prospect tomorrow, and then do what we can during the bad weather while waiting for the sun again. The only good thing is at home it's going to be below freezing and snowing for the same period of time. I won't miss that..guaranteed...LOL
Jim

Sorry to hear about the damper on your trip. We get these every 10-11 years. I think they call it the Pineapple Express, as the storm bands funnel in from the Hawaii area. Hope you can get some fun in.

 

[russau]

I like the idea of a CNC cutting this out BUT who can afford the $$$$$$$$$ it'll cost ! BUT idea's are stimulating this ole bum !

 

[Jim in Idaho]

I like the idea of a CNC cutting this out BUT who can afford the $$$$$$$$$ it'll cost ! BUT idea's are stimulating this ole bum !

I thought seriously about using CNC, but decided I was thinking of using an elephant gun against an ant. One of the negative traits I'm working to overcome is a tendency to overthink everything. Making the grooves in a shaker table is just not that difficult. I decided it would take me longer to learn to program the CNC than to carve the grooves with a dull knife...LOL
Jim

 

[Jim in Idaho]

Just cut the grooves the same depth to the length needed then ramp the ends. It could be done with a plunge router or a file. I used a piece of 1"x 2" clamped as a guide and a worm drive saw. It would be nice to know someone with a CNC Router and let the computer cut the grooves. To add to this I was going to use door shims or a couple of cedar shingles as guides on the end of each groove after I cut all the grooves to ramp. Just ramp one at a time the shims go from paper thin to a 1/4 inch or more.

You can do that, and people do, but I think there's loss of recovery efficiency over having a gradual taper the whole length.
Jim

 

[N-Lionberger]

I’m using tapered raised riffles on my deck is there an advantage to grooves vs riffles?

 

[southfork]

I’m using tapered raised riffles on my deck is there an advantage to grooves vs riffles?

Good question I think ultra fine gold needs the water flat, so it drops into the grooves. With riffles you need more flow to get that vortex affect to move and concentrate the material. Thats just my thoughts no science behind it.

 

[Jim in Idaho]

I’m using tapered raised riffles on my deck is there an advantage to grooves vs riffles?

Ya know, I honestly have no idea. I built my original table as a semi-copy of What the BGS did with their portable table, and they used (tapered?) riffles. So I used tapered riffles on mine. But, the current trend seems to be grooves, so I'm going to try that on the next one. There weren't many using grooves when the BGS designed theirs, so maybe that effected their thinking.
Jim

 

[Jim in Idaho]

Sorry to hear about the damper on your trip. We get these every 10-11 years. I think they call it the Pineapple Express, as the storm bands funnel in from the Hawaii area. Hope you can get some fun in.

Not a big deal, Caley. Raining lightly right now. We're snug in the Casita, and Chris is about to fix breakfast. We got a lot done yesterday, but unfortunately the results e got were a negative. Did some 2-probe resistance checks to a depth of 70' in 10' increments. We got zones of varying results, but were looking for a 5:1 change that continued as it went deeper, and we didn't get it. So that decided it, right there. No more work on that occurrence. The rest of the trip will be spent wandering the area until the weather clears. We have two days of decent weather coming tomorrow, and Saturday.
Jim

 

[desertgolddigger]

Just to let you know, someone mentioned cutting your board to final shape before routing in the grooves, or that's the way it sounded.

My opinion is to route the grooves min. The rationale is there's more space on an uncut blank to place your router jigs on, and also more places you can clamp things without interfering with the router and jigs.

Thank goodness I didn't cut my tabletop completely to size and shape. As it is, I have to user a sheet of galvanized steel I have as a base in order to use magnets to hold my blank, and a way to hold my router jig in place.

This is just my opinion. It may be easier when doing a full sized table.

It I get the chance, weather permitting, I'll do my first trial groove. My idea of just shimming under the jig where the router bit should supposedly exit was incorrect. The actual shim placement is more like 5-6 inches farther than the end of the groove. Entry point is no problem, but setting up the exit point takes a lot of experimenting/eyeballing to get it, at least close.

 

[Jim in Idaho]

Just to let you know, someone mentioned cutting your board to final shape before routing in the grooves, or that's the way it sounded.

My opinion is to route the grooves min. The rationale is there's more space on an uncut blank to place your router jigs on, and also more places you can clamp things without interfering with the router and jigs.

Thank goodness I didn't cut my tabletop completely to size and shape. As it is, I have to user a sheet of galvanized steel I have as a base in order to use magnets to hold my blank, and a way to hold my router jig in place.

This is just my opinion. It may be easier when doing a full sized table.

It I get the chance, weather permitting, I'll do my first trial groove. My idea of just shimming under the jig where the router bit should supposedly exit was incorrect. The actual shim placement is more like 5-6 inches farther than the end of the groove. Entry point is no problem, but setting up the exit point takes a lot of experimenting/eyeballing to get it, at least close.

Yeah...if you don't want to make precise shims, you have to slide them under the ribs to get the angle you want. All this stuff is a PITA, but necessary. Good thing you're not making a LUNAR Lander, Caley...LOL (go Air Force)
Jim