Deep Pour Epoxy Calculator
Deep pour epoxy is a specialized product designed for river tables, casting blocks, and pours over 1 inch thick. The calculation is straightforward — but heat management across multiple layers is what separates a successful project from a cracked, yellowed disaster. This guide covers both.
Use the free calculator to plan your deep pour layers and total resin volume.
Calculate Epoxy Amount →Volume Formula for Deep Pours
Volume (mL) = Length (cm) × Width (cm) × Depth (cm) × 10
For river tables, measure the average width of the river channel at several points, then calculate volume using that average. Most channels range from 30–50% of the table's total width.
River Table Resin Estimates
Based on a river channel that is 6 inches wide (a common ratio for a 24-inch wide table). Adjust for your actual channel width.
| Table Length | Channel Depth | Resin (6" wide channel) | Resin (8" wide channel) |
|---|---|---|---|
| 48 in (4 ft) | 2 in | ~32 fl oz (0.25 gal) | ~43 fl oz (0.33 gal) |
| 60 in (5 ft) | 2 in | ~40 fl oz (0.31 gal) | ~53 fl oz (0.41 gal) |
| 72 in (6 ft) | 2 in | ~48 fl oz (0.37 gal) | ~64 fl oz (0.50 gal) |
| 84 in (7 ft) | 2.5 in | ~70 fl oz (0.55 gal) | ~93 fl oz (0.73 gal) |
| 96 in (8 ft) | 2.5 in | ~80 fl oz (0.63 gal) | ~107 fl oz (0.83 gal) |
| 96 in (8 ft) | 3 in | ~96 fl oz (0.75 gal) | ~128 fl oz (1.0 gal) |
Add 15% for wood absorption and overpour buffer. These are channel-only volumes — add a flood coat for the full tabletop surface.
Deep Pour Resin Types — Max Pour Depth
| Resin Type | Max Single Pour | Cure Time | Best For |
|---|---|---|---|
| Standard table top epoxy | 1/4 in (6mm) | 24–48 hrs | Coating surfaces only |
| Deep pour / casting (standard) | 2 in (50mm) | 36–72 hrs | River tables, small casts |
| Deep pour / casting (heavy) | 3–4 in (75–100mm) | 48–96 hrs | Thick casting blocks |
| Ultra-clear deep pour | 4+ in | 72–120 hrs | Large casting, inclusions |
Layer Planning — 6-Foot River Table, 2.5 Inch Deep Channel
| Pour # | Depth Added | Cumulative Depth | Volume (6" chan.) | Wait Before Next Pour |
|---|---|---|---|---|
| Pour 1 | 1.5 in | 1.5 in | ~36 fl oz | 36–48 hrs (firm gel) |
| Pour 2 | 1.0 in | 2.5 in | ~24 fl oz | Final cure: 72 hrs |
| Total | — | 2.5 in | ~60 fl oz | — |
⚠ Exothermic Warning: Pouring more than the recommended depth with standard epoxy causes runaway heat buildup. The resin can crack, yellow, smoke, or in extreme cases ignite. Always use a deep-pour formula and stay within its rated depth. Never pour regular table-top epoxy more than 1/4 inch deep in a single pass.
Heat Management Tips
- Cool the room: Work in a space at 65–72°F. Warmer temperatures accelerate the exothermic reaction and raise risk.
- Cool the resin: For large batches, place the mixed resin container in an ice bath for 5 minutes before pouring to slow the reaction.
- Pour in layers: Even with deep-pour resin, thick sections (over 3 inches) should be done in 2 layers with a full cure between them.
- Don't enclose the project: Keep the project in open air during cure. Enclosing generates more heat.
- Use slow hardener: Some systems offer slow, medium, and fast hardeners. For deep pours, always use slow hardener — it generates less heat per unit time.
Frequently Asked Questions
How deep can you pour epoxy in one layer?
Standard table-top epoxy should not exceed 1/4 inch per layer. Deep pour casting resins are formulated for 2–4 inches in a single pour. Always check the product's spec sheet for its rated pour depth.
How much deep pour epoxy do I need for a river table?
For a 6×60 inch river channel at 2 inches deep: 720 cubic inches ÷ 1.805 = ~399 fl oz (~3.1 gallons). Add 15% buffer for absorption and waste: ~3.6 gallons total for the channel fill.
What happens if you pour epoxy too deep?
Excessive depth triggers uncontrolled exothermic reaction — the resin generates too much heat, causing cracking, yellowing, smoking, or fire in extreme cases. Always respect the manufacturer's maximum pour depth and use deep-pour formula for thick casts.