Resin and epoxy river tables

Overview

A river table is two live-edge slabs, or one slab split down the middle, set apart and filled with casting epoxy to look like a river flowing through the wood. The resin may be clear, tinted, pigmented or metallic. It is a finished-object look rather than a wood species: you are paying for the Live-edge slabs, the resin, and a lot of careful work. People pick it for a statement piece, and it is among the most skill-demanding projects in this guide.

Pros

• Bold, modern look that shows off the slab edges.
• Resin can stabilise cracks and voids that would otherwise ruin a slab.
• Can rescue a split or narrow slab pair into a wide top.
• Colours are limitless, from clear to opaque.

Cons

• Cost and effort: wood, resin, moulds, release agent and finishing materials add up.
• Heavy, and prone to heat marks and scratches.
• Resin cure is exothermic and can overheat; deep pours need the right product and depth.
• Epoxy can sensitise skin; a single exposure may be enough.

Variants and subspecies

• Clear river: transparent resin between two slabs.
• Coloured or pigmented river: translucent dyes, mica or opaque pigment.
• Inlay or fill: resin used only to fill cracks, knots and voids in a single slab.
• Resin type: tabletop epoxy is for thin coats; deep-pour or casting epoxy is slow-curing and low-exotherm.

Working and finishing

Dry the wood: resin-expert advises moisture content below 12 percent, then seal the wood generously with resin so it does not outgas into the pour. Bondcraftor describes deep-pour epoxy as a slow-curing, low-exotherm epoxy designed for pours of 2 to 4 inches per layer, and warns against substituting tabletop epoxy; another maker notes some casting epoxies are limited to one inch and others to two, so read your product's directions. Wikipedia notes that curing is exothermic and, in some cases, hot enough to cause thermal degradation. Pour in layers if the channel is deep, then flatten, sand and finish both resin and wood.

Staining and finishing colour

Resin and wood take finish differently. Finish the wood with oil or hard-wax oil, or a clear topcoat over both. Do not stain resin; colour it with dye, mica or pigment before pouring. Wear a respirator when sanding cured epoxy, because Wikipedia notes sanding dust of epoxy compounds, especially if not fully cured, can cause respiratory problems.

Sustainability and handling

Epoxy is not a green material, and a cured table cannot easily be recycled or repaired. West System states that fewer than 10 percent of epoxy users react when overexposed to resin or hardener, usually with contact dermatitis, and that less than 2 percent are likely to develop allergic dermatitis (sensitisation), which can occur after many exposures or just one. Use gloves and ventilation, avoid skin contact, clean spills with the manufacturer's recommended method, and keep partially cured sanding dust off skin. Heavy tops need a strong base and two people to move.

Popular projects

Dining, coffee and console tables, desks, bar tops and shelves: anywhere a wide slab pair is the focal point.

Buying notes

Most people build rather than buy. Buy slabs kiln-dried (walnut at $13 to $28 per board foot from Lancaster Live Edge; rustic slabs at $3 to $10 from Cassens) and a deep-pour resin sized to the channel. Check the resin's maximum depth per pour and its cure time. Ready-made tables are common but expensive; check the wood moisture, the resin bond, and any bubbles or yellowing before paying.