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 a pour deeper than your product’s rated depth, often about 2 inches, has to be split into lifts.
Last updated October 22, 2026
Deep pour epoxy cures via an exothermic reaction, and too much mass at once traps heat, which can crack, cloud, or yellow the cure. Pours deeper than the product’s rated depth (often about 2 in) need to be split into multiple lifts, with a wait between each that your product’s TDS sets. 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 your product’s rated depth (often 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 a 2 in rated depth, the calculator’s default), 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 the rated depth, which is a common way to crack, cloud, or yellow a river table
- Not waiting the time the TDS sets between lifts (24 to 36 hours is common, longer in cool temperatures, and some products want the previous lift fully cured)
- Using a fast hardener where the product calls for 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 holds a lot of heat in a thick mass, so an off-ratio batch has more room to overheat. 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 a pour deeper than the product’s rated depth gets split into multiple lifts instead of one pour. Ratings vary by product, from about 1.5 in to 4 in per pour, and about 2 in is common, so check your TDS.
How long do I wait between lifts?
Your product’s TDS sets it. 24 to 36 hours is common, longer in cool temperatures, and some products want the previous lift fully cured before the next goes on. Some installers use an infrared thermometer to confirm the previous lift has cooled to near room temperature before pouring the next.
Do I need a special hardener for a deep pour?
Use the hardener your deep pour product specifies. Many kits ship one slow hardener engineered for a lower rate of heat buildup; if yours offers speeds, pick the slow or extra-slow one for thick sections. 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.