My first post here, been happy to be a reader for a long time though and this topic caught my eye, got reading and I too have a GS21 that I have been playing round with and making adjustments to as well. Out of the box the GS21 felt a little smaller than expected and somewhat roughly finished, but I guess you get what you pay for and I really did get it cheap thanks to an Ebay 25% off sale and I do like the clay/dirt bustin hopper, in the field it really does bust up material. I think 2017 will be the year of the Gold Rat 12" Outback Pioneer Series for me, or maybe the Gold Hog Raptor Flare 2.0...if i can get over the international freighting cost!
First thing I did with the GS21 was to put some feet on the legs as I found them a little unstable and they tended to bury a bit, constantly adjusting the height and level when I took it for its maiden run.
They say to run the header box fairly flat, but I found that it was having trouble clearing the grizzly bars (I feel they may be a bit too close together), it helps to have a 2nd set of hands sitting there helping to clear it but if its just one person it can be a pain so I put some extensions on the bars that hold the header box up to increase the pitch....seems to be working much better. I put a big tray at the back of the grizzly's ran a few buckets and then test panned, was not losing anything and the rocks were washed clean. I kinda wish the grizzly's were adjustable/removable so I could play around and make some a bit wider or with a bit more spring.
I took the carpet out and also replaced it with V mat and miners moss over the top, exactly how you have it. The only thing I did differently is fabricated a clamp for the mat, pretty much the same as the Gold Rat Highbanker mat clamp, looks like a Hungarian riffle. It allows the water to pool a bit before material hits the moss.
I'm also thinking about putting in a square of raised aluminium punch plate at the back of the sluice for what His Holiness, "Doc" from Gold Hog calls a "quiet capture zone similar to a quasi fluid bed" and changing the existing expanded mesh (which is tiny) out for some with a larger profile around that 8mm high by 38mm x 19mm? and width and maybe getting rid of the original riffles altogether or make some Hungarian riffles to suit......actually finding the punch plate and expanded mesh off cuts to suit is the problem, Hen's teeth right?
Pretty keen to see how your trip goes Boulders I hope you see a major difference in the amount of yellow you are capturing.
Looks like tomorrow should be nice so I'm heading up the upper Turon around Palmers Oakey in the morning, hopefully get some good colour
