I googled it before I asked but not with TNet. I saw this in images when I looked up the gold grabber 4" dredge. It said it was saved to Pinterest from Tnet. I was hoping someone might remember it. I'll keep digging. Thanks for replying.
Are you looking to make a sump on the end of the sluice? This is something similar that I made. It worked but wasn't really worth carrying around the extra gear.
Years back I made a fluid bed for the rear of my 4 inch dredge. Yes it caught gold but also lots of black sand that is heavy and it lowered the rear of my dredge like it was doing a wheelie. I got rid of it and was going to make another fluid bed to be mounted in the middle of my sluice. I never got around to making it happen .
You are going to lose some gold no matter what you do, the best way to try and save it is to construct an undercurrent classify the material so it is mostly fines and slow the water down, your classifier should do this. You could also jig your undercurrent a little this helps the heavier fines to drop out quicker.. it's very interesting to play with good miners Moss too really traps the fines..l the shape of the gold has a lot to do with recovery, thin flat pieces tend to float and sail over riffles it's the heavier looking pieces that are easier caught. . Then too no matter what you do your black sand production will increase but that's just part of gold recovery... Have fun I did. I learned a lot and was able to better recovery.