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System Three Rivercast Epoxy

System Three Rivercast Epoxy
System Three Rivercast Epoxy
System Three Rivercast Epoxy
System Three Rivercast Epoxy
System Three Rivercast Epoxy

RiverCast is an clear epoxy system designed specifically for woodworking casting applications.  It produces ultra-clear casts with minimal bubble entrapment.  Use RiverCast to make beautiful river tables or to fill large inclusions in wood substrates. For small voids, use MirrorCast.

  • Fill voids up to 1.5” thick in a single pour
  • De-aerates rapidly
  • Contains no VOCs
  • Easy 2:1 mix ratio

Working Conditions:

In the winter months, RiverCast may be exposed to very low temperatures during transit. In some cases, the Part A can turn cloudy from the exposure to cold temperatures. If the Part A is cloudy, it will need to reconstitute the material. Heat the Part A only in a water bath at approximately 120°-130°F throughout. Once the Part A returns to a clear state, no further heating is necessary. Allow the material to return to room temperature before beginning your project.


Building a Form:

When fabricating a river table or when filling large inclusions that go through the entire slab, it’s necessary to build a framework to contain the epoxy. Plastic sheet goods or smooth, rigid plywood covered with clear packing tape work well for constructing a non-stick form.

In most instances, large slabs are not perfectly flat. The form material when mated against the wood slab may have intermittent gapping along its length. Gaps can be closed by drilling pilot holes through the non-stick material. Use screws that easily pass through the pilot for maximum effectiveness. Once the form is complete, use a carpenter’s level to level the slab in both directions.



Pre-sealing the walls of the void prevents large air bubbles from forming in the epoxy. After curing overnight, the seal coat will likely be tacky. The RiverCast can be poured over the tacky seal coat without issue.


Before filling the void with RiverCast, inspect the seam between the wood substrate and the non-stick material for gaps.


Mix Times:

Drill and Paddle Mixing

1 Gallon3-5 Minutes
2 Gallons4-6 Minutes
3 Gallons6-8 Minutes


Hand Mixing

1/4 Gallon3-5 Minutes
1/2 Gallon3-5 Minutes
1 Gallon4-6 Minutes


For batches larger than 1 gallon, use a drill and paddle mixer. The Jiffy mixer brand is an excellent choice for mixing larger batches of RiverCast. This mixer is available on the System Three website or most paint stores



The surface of RiverCast will initially be filled with bubbles from the mixing process. These bubbles will dissipate within 4-6 hours. Also of note is the surface in this timeframe will have a skin-like appearance. This too will dissipate within 4-6 hours.

If constructing a river table, it’s best to keep the slab contained within the form for a full 7 days. In the early days of cure, the epoxy is underdeveloped and could possible warp or bend if not fully supported. Keeping the slab supported and contained as it cures greatly minimizes potential unwanted movement of the wood slab/epoxy.

Casting resins are designed to cure very slowly. This design feature allows the end-user to pour large volumes of epoxy without experiencing a runaway exothermic reaction. Because of this slow cure, it can take RiverCast multiply days to harden.

Mix Ratio by Volume100:50
VOC Content0 g/L
Mixed Viscosity260-290 cps
Minimum Curing Temperature70° F (21° C)
Working Time @ 70° F (21° C)3 hours

Measure the length (L) x the average width (W) x the average depth (D).


L x W X D = total cubic inches. From the total cubic inches see which RiverCast kit meets your needs. It’s advisable to pad your estimate by 10% to ensure that enough material is available.


RiverCast Kit SizesCubic Inches
1.5 Gallon Kit346
7.5 Gallon Kit1,730
15 Gallon Kit3,460

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  • Stock: In Stock
  • Model: Rivercast
  • Weight: 15.00lb
  • Dimensions: 18.00in x 12.00in x 16.00in

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