Backpack Sluice Box

Why this design

Most store-bought sluices are either too heavy to hike with or too flimsy to trust. This one started as a cardboard mock-up and went through three versions before I was happy with it. The sides fold down, the riffle tray lifts out, and the whole thing slides into a daypack.

Cut the sheet

1. Lay out the cut lines from the PDF on the flashing with a marker. Double-check the fold lines before cutting anything.
2. Cut the outline with tin snips. Take small bites so the edge stays straight.
3. File every edge. Flashing is sharp and you will be handling this wet.

Fold the sides

Clamp the sheet along a fold line to a table edge and work it over slowly with a block of wood. Aim for a clean 90 degrees. Do the long sides first, then the flare at the head end.

Riffle tray

The expanded metal sits on the rubber mat and gets held down by the four printed clips. Drill the clip holes after the sides are folded so everything lines up.

Tip: Angle the riffles so the open side of the mesh faces downstream. It catches noticeably more fine gold.

Field notes

• Set the sluice at about one inch of drop per foot. Faster water blows out the fines.
• Clean out every 30 to 45 minutes when the material is rich.
• After a season the rivets at the head end loosened. Version two uses stainless rivets there.