How To Build A River Table

Prepare the Wood

Make sure whatever wood you use is dried and seasoned. If you buy your live edge slabs from a lumber store, they should already have been kiln-dried.

Clean up any bark and sand off any loose material from the live edges. You need to create a good clean surface for the epoxy to bond to. Cleaning the surface also eliminates voids that could trap air bubbles during pouring, and it adds to the strength of the tabletop.

Once your slabs are prepped you can start to cut them to the desired length. Make sure the ends and edges are square. We’re using a table saw, but you can do this by mitre saw, track saw, or even circular saw with a straightedge.

Alright, now it’s time to start building the mold. Cut the base and side pieces to your desired dimensions. We used melamine, but MDF or plywood will also work great for this. Make sure the sides of the mold are at least half an inch taller than the thickness of the slab, to avoid any overflows during the pour. Cover the pieces of your mold with sealing tape, like this tuck tape. We recommend using screws to put the mold together. This will help when it comes to removing the mold later. Apply a bead of silicone to the inside corners of the mold. You could also tape the edges but silicone is easier to apply and better at creating a leak-proof seal.

OK, the mold is finished, and it’s time to clamp down your boards. The wood would float in the epoxy otherwise, so this keeps them flat and in place. Now, it’s really important you don’t screw the slabs from underneath. All epoxies experience a small amount of expansion and contraction during the curing process. The slabs could pull apart if they aren’t free to move a little, that’s why clamping is best. Ensure that the form is level and as leakproof as you can make it. The last thing you want is a blowout. It’s also a good idea to put down a piece of poly below your mold, to ensure any blowouts end up on the poly, and not on your floor.

The next step is to figure out how much resin you’ll need. In the past, that meant figuring it out with a formula and a calculator, but now we can use the handy FlowCast Volume Calculator. The link is right there on the front page at EcoPoxy.com. Just figure out the average gap between the slabs and enter that as the width. Then enter your length and depth measurements into the volume calculator, and it’ll tell you the volume of FlowCast you need in gallons, or in litres. The volume calculator even includes an additional 5% in the calculated volume, to account for resin that may fill any voids and cracks in the wood during the pour. In this instance our average gap was 5.5inches, the length was 50 inches, and the depth was three inches. So, when we plug that into the volume calculator that gives us 3.75 gallons, or 14.2 litres. We always round up to ensure we have enough product, so for this table we ended up using 15 litres of Liquid Plastic. If we did that pour today, we’d use the same amount of FlowCast. Both products are a 2:1 mix ratio by volume, which can pour up to 1.5 inches in a single pour. Always mix the desired amount of resin with exactly half the amount of the hardener, and then mix until clear. Now we’re going to add the pigment. For this table we’re going to use one of our metallic pigments called caviar. We wanted the river table to be opaque, so we’re going to add about half of the 15-gram container of pigment. You could also use regular pigments for a solid colour, or maybe add polyester glitters, or even no pigment for a glass-like appearance. Once the epoxy is mixed, let it rest for 15 to 20 minutes. This eliminates a lot of the air bubbles.

Now pour the deep cast resin, making sure to get every part of your table. We want to pop any remaining air bubbles. We used a torch, but a heat gun also works. As you may have noticed, this pour is a lot thicker than the recommended 1.5inch depth, but you can do thicker pores if you have proper heat dissipation. So, we’re going to set up these two fans to help dissipate some of the heat that’s generated during the curing process. You only need to turn on the fans when the temperature approaches 30 degrees Celsius, or 86 Fahrenheit, and that occurs around 6 to 8 hours after the pour. If you’re going to exceed 1.5 inches in a single pour, make sure you use an infrared thermometer to keep an eye on the temperature. Now we’re going to let it cure for a full 72 hours. Ok it’s been three days, and now it’s time to unscrew the mold. Remove the sides and the back gently with either a putty knife or a pry bar.

You can finish the tabletop with a belt sander, like we did, or you can use a planer, or even a router with a router sled jig. Once it’s flat and smooth on both sides, it’s time to start sanding. Always start coarse and slowly increase to a finer grit. For this project, we sanded the wood all the way up to 220 grit. We sanded the epoxy section to a 320 wet-sand, removing all the marks from the previous rounds of sanding. We wanted the table to have a satin look, so we finished it with two coats of Osmo Polyx-oil clear satin hardware oil finish, but for a durable glossy look, you could always use our UVPoxy crystal clear coating resin as a final topcoat.

And just like that, we’ve turned reclaimed wood into a beautiful one-of-a-kind coffee table you’d be proud to display in your living room. Thanks so much for watching, we really hope you enjoyed seeing how a table like this comes together. If you want to see more videos like this one, you can subscribe to our YouTube channel, and while you’re there, be sure to click the notification bell, and hit the like button. You can also like and follow us on Facebook, and Instagram, and visit us any time at ecopoxy.com.

Thanks again.