How Much Epoxy for a River Table or Deep Pour (Lifts, Pours & Wait Times)
Deep pour epoxy cures via an exothermic reaction, which is why depths over about 2 inches need multiple lifts, not one big pour.
Deep pour epoxy cures via an exothermic reaction, and too much mass at once traps heat, which can crack, cloud, or yellow the cure. Depths over about 2 in typically need to be split into multiple lifts, with a 24 to 36 hr wait between each. The calculator handles the volume math for rectangle, round, or river-table shapes; the lift count is guidance you plan around it.
How to read the inputs
Mold Shape
- Rectangle, round, or river table, and each shape asks for the dimensions it actually needs
River Table Dimensions
- Table length and width, plus both slab widths. The calculator subtracts the slabs from the width to estimate the river gap
Pour Depth, Total
- Your full intended depth. Past about 2 in, plan multiple lifts rather than one pour (see the FAQs)
Waste / Overage Allowance
- Defaults to 0%. The app’s own guidance is that 5% to 10% is typical for mixing residue and mold seepage
Worked example
A river table: 84 in long, 36 in table width, with 15 in and 14 in slabs, so the two slabs leave a 7 in river gap. Footprint = 84 × 7 = 588 in². Poured 3 in deep: volume = 588 × 3 = 1,764 in³, or 1,764 ÷ 231 = 7.64 gal raw. With a 10% waste allowance: 8.40 gal total to order. At 3 in deep (over the roughly 2 in single-pour threshold), this pour needs 2 lifts of about 1.5 in each, not one shot.
Try it with your own mold
Pick your shape and enter its dimensions plus pour depth. Waste defaults to 0%, so dial in 5% to 10% yourself.
Full result gives total gallons, quarts, fl oz, and liters to order.
Open the live calculator →Common mistakes
- Pouring the full depth in one shot past about 2 in, which is the single most common way to crack, cloud, or yellow a river table
- Not waiting long enough between lifts, when 24 to 36 hours is typical, longer in cool ambient temperatures
- Using a standard fast hardener instead of a slow or extra-slow one rated for thick sections
- Treating the river gap estimate as exact for a wavy live edge. Measure at a few points along the river and average them
Deep pour resin is one of the most ratio-sensitive products on the site, so see epoxy mixing ratios explained before you mix a batch.
Frequently Asked Questions
Why can’t I just pour a deep river table in one shot?
Deep pour epoxy cures via an exothermic reaction, and too much mass at once traps heat, which can cause cracking, cloudiness, or yellowing as it cures. That’s why depths over about 2 inches typically get split into multiple lifts instead of one pour.
How long do I wait between lifts?
24 to 36 hours is the typical range, depending on the product and ambient temperature, so check your product’s TDS. Some installers use an infrared thermometer to confirm the previous lift has cooled below roughly 85°F before pouring the next.
Do I need a special hardener for a deep pour?
Yes. Deep pour products use a slow or extra-slow hardener engineered for a lower rate of heat buildup. A standard fast epoxy hardener is not rated safe for thick sections.
How accurate is the river gap estimate for a live-edge slab?
It’s a straight-line estimate from your two slab widths. For a wavy live edge, measure the actual gap at a few points along the river and average them for a more accurate number.