Hi, I’m looking at re configuring the dredge I recently brought, it’s been well made by someone in the South Island previous to who I brought it from.
It runs a swimjoy pump on a 9 hp honda engine.
( my mistake it’s a gx 140 5.5 hp running a p180 equivalent pump.) Suction hose is 3 meters.
It’s clear from the great help I need to classify and build a wider box. Will email and thank those who have generously contributed personally.
I have 17 riffles 50mm x 250mm, with classification this may help keep the boxes open and stop clogging? (Insert some technical term here)
Mixing in expanded mesh may also help clearing and capture?
I’m chasing flood gold so is flaky and light. Maximum size to date is .3gm
I. Working my permit near Kumara, West Coast.
Problems, tends to block up the pipe unless running at 3/4 or above, resulting in jetting out over the box.
It’s got a 5 inch suction pipe on it which is probably over sized for the pump.
The box is 250mm wide by 1700mm long. It runs riffles and collects lots of rocks etc. It has about 100mm deep of water when running going through the box and the end of the box is submerged… the force of water going out seems to not cause any back pressure.
I tend to have better recovery with my hand sluice box.
Improvements, I am looking at or have done.
I put a grate on the nozzle to reduce the size of rock going through and blockages but it just means less production and more arm and hand work.
Would periodically stopping dredging and running full throttle to clear the suction hose upset the sluice bed if not picking up gravel?
When things open up again, I want to set up a classifying mesh or punch plate in the box, this will have a wave at the start to deflect any jetting due to blocked up suction hose.
Does anyone have experience with gold hog Matt’s or dream Matt in a dredge? I guess they would reduce the concentrates but imagine the rocks rolling would unsettle the bed holding the gold.
If I run it over 3/4 throttle I am concerned the light flood gold will float away.
Pros of the unit is the portability and width, can break down and carry into tight gorges…
Classification is probably the most urgent , with a longer and heavier dampening mat, in future will re engineer a wider box. It wouldnt take much to lift the box and engine.
If any one has some suggestions or input that will help that would be great.
New users can’t put up more than 1 photo sorry.