Running the A51 without expanded?

[wingmaster]

How would running the keene A51 without the expanded metal under the riffles affect the gold catching ability, for one I notice the bottom bowing when I lock down the riffles, like maybe they got the clamps are mounted a little low on the sides and I'm sure its not a good thing that the bottom of the sluice isn't flat of course I could fix this easily but I notice like others have said that the riffles have a gap under them with the expanded in the sluice. Anyone want to share some picks and advice of a keene sluice they modified. Thanks for any info you guys are great for people starting out that don't have the experience

 

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[Hoser John]

Bad fabrication job. The expanded helps to keep bigger rocks moving and helps to create a area under rocks that cap it for gold to gravitate too. Drill out the riffle retention holes 1 drill size up to get what ya need. CAUTION as hole to big and you'll lose the seal between the L flat bottomed riffle and the expanded. Is it new as carpet squishes a bit and seals better down the road as stiffness relaxes-John

 

[wingmaster]

Yep its a new sluice but when I clamp it down the sides bow in and the bottom bows out a little so the bottom isn't flat anymore, I was just thinking of filing down the holes on the top bar of the riffles a little where the latch hooks in as its really tight when snapping down the latches and I'm thinking it would be better doing that than having to drill out the latches and rivet them back. I like the expanded being there as they seem to catch a lot of black sand and I'm thinking it wouldn't hold the find gold as well without it.

 

[GrizzlyGremlin]

I refuse to disagree with any of the expertise you have been given but if your new, setting up a stream sluice can be difficult at first. If you are chasing very fine gold expanded and riffles wont catch all of it. You can rip out all the riffles and expanded and use just v rib all the way down your sluice. This lets you run at very low speed and catch it ALL. The downside? You can run about1/3 the material because you must classify down to at least 1/4". This setup is very forgiving. Keep the riffles and expanded tho. You will want them if you plan to run more material. I use 12" wide deep v at the end of my sluice. My keene a51 catches 70 to 90%. The v rib off the back catches the super fine stuff very nicely.

 

[wingmaster]

Yep was planning later down the road to add something on to the end, maybe another 3' section of some matting.

 

[DizzyDigger]

Just last night (early this morning?) I modified my A52 and removing the riffles,
expanded metal and carpet, and replaced it with v-matting for the full length,
with expanded metal over the top. This sluice has been run in it's original
configuration since I bought it back in the early 1980's, and I'm looking forward
to doing some experimenting to see if I can improve the fine gold retention.

I've got a local creek that doesn't show much gold over 20 mesh, but the
black sands are loaded with gold down to 200 mesh and beyond. My goal is
to classify down to <20 mesh, and collect as much of that black sand as possible.
In the process of building a 18" x 60" Miller Table with a slate top, and when winter
returns I'll have a few 3 gal. buckets loaded with that black sand concentrate
to run. No idea how much gold I'll actually end up with, but it's the best way
I can come up with to mine enough of this material to potentially make it worthwhile.

Pics added as thumbnails, so best to expand them to full size for max sharpness.