Eastbay Gold Prospecting & Treasure Hunting Club

I just finished up an overhaul of my Keene A52 sluice. For too long I trusted that it was a great design and working as it should. Yet I always wondered why the miner’s moss would quickly load up?

Seeing all the different sluices now available, many with no moss at all, made me take a closer look at the A52. I built a custom sluice for higher flow rates using the Gold Hog mats and no miner’s moss. It seems to work great so I decided to take a closer look at the A52’s miner’s moss zone. Son-of-a-biscuit, the moss was puffed up higher than the riffles. Instead of working riffles, mine were filled up by the moss. No wonder the moss never cleaned itself out.

I replaced the moss with the stiffer GoldHog moss, put V-groove mat below and slid the A52’s small expanded metal to the front over the moss. Now the riffles are absolutely clear and can start working! The heavies that get caught behind the first riffles can drop into the moss and find their way down to the V-groove mat. The new design theory being the gold likes to hide as deep as it can go and give it different surfaces to travel over. Makes sense as we work different streams, the water flow and materials dumped in the sluice will vary. I started with Plan A in my mind and ended up about Plan C or D. The front end of the sluice went from squishy miner’s moss thickness to V-groove mat under thicker moss under small expanded metal. So now the stream flow meets at least a ¼” high dam where the riffle assembly plugs into the sluice. Since we would want a nice laminar (smooth) flow of stream water entering the sluice, this was looking problematic. I took some quick height measurements and headed over to Gold Pan CA. I talked to Mike Dunn and his helper. They dug around the shop a few seconds and out comes a 10” sluice riffle. I hold it in place upside-down, measure it, looks good! They weld it on the spot and painted it. Now, when I put all the layers in place and lock down the riffle assembly, the new upside-down riffle ramp lands perfectly on the inspection mat. Very sweet (and lucky).

I now have three sections of moss covered with the small expanded metal. This will prevent moss in general from blocking the riffle action and add some action of its own to keep the moss cleaned out. At least that is my hope.

The next two sections are GoldHog UR mat with the rest of the expanded metal. The last two sections are naked UR mat. I’m sorry I didn’t try this sooner but it took me awhile to work things out in my mind regarding how riffles should work and the different ways to vary the sluice surface to mix things up.

This should help the nomad prospector that can’t fine tune his sluice by working the same spot all the time. If something ain’t working, try something else, even if it’s wrong.

Dale, That looks fantastic!! I think your going to need a bigger snuffer bottle to handle the extra gold you'll capture!!!!

Gonna need tweezers for all the pickers!

Tongs!!

I'm taking an example from you Dale and remodeling my A52 too. I just received Razor Back and Scrubber mats from Doc and I'm spending some time today to install them. I'll test the new sluice at the July outing.

Hi Robyn,

A while back I posted about building a GH mat sluice. I like to have options during for different water flows. What I don't like about the GH mats were the single width they come in.....36 inches. Sounds like they are aimmed at the dredge market. My solution was having Spencer at South Yuba Mining Co. make me a custom width sluice with an expanded metal trap at the end. The mats are a tricky to cut to the perfect width and with an A52 you end up up wasted mat. I had Spence make the sluice a hair under 9 inches wide so I ended up with a few little scraps of mat. The expanded metal (like the A52 riffles metal) keeps my GH Mats in place and not flowing down the river when I'm not looking. A little ramp for the water to flow over keeps the matting trapped at the top end. Will attached the pictures and hope this helps you with ideas. The GH videos show using doubled over duck tape on the sides for a tight fit. Could get that part figured out since no matter how hard I tried, I couldn't cut the mats perfectly to a parallel width. No worries with the trap at the top and the expanded metal holding the bottom. The stuff catches the really fine gold nicely. Now I just need to find some bigger gold so I can say it catches both!

Hope this helps.  Even have the pink "cons" bucket ala Doc.

Back to the A52! I don't think I posted the results so here are 2 pictures, one in the water and one after it was pulled for the clean up. The results were as hoped. The riffles remained active and did not simply load up the moss as before. Now I just need to get to some better gold bearing areas!

I'm happy to see the results after all the work but again now it's time to find some better color. This trapped an impressive amount of fines fit for the blue bowl. Lots of -100 stuff but more work to recover than the value of the find.

But the point is it was there, not headed down stream with the rest of the light stuff!!!

Really nice guys! I did use Gorilla Tape to fit the mats and they're tight, maybe too tight. I hope the river is still flowing well enough to run the A52.