Epoxy River Table Sanding: 80–240 Dry, 400–3000 Wet

Epoxy river tables look spectacular—until swirl marks, cloudy bands, or uneven reflections spoil the illusion. Getting that glassy, distortion-free surface isn’t magic; it’s a disciplined sanding process that stays flat, controls heat, and uses a tight grit ladder. This guide walks you through a proven sequence: 80–240 dry for shaping and flattening, then 400–3000 wet for clarity—finishing with quick buffing for mirror gloss.

Why Sanding Epoxy Matters

Epoxy cures hard but can still print sanding mistakes. Heavy pressure creates heat that smears resin and clogs sheets; skipping grits leaves deep tracks that appear as hazy lanes under polish. A smart approach (1) levels wood-to-epoxy transitions without dishing, (2) tightens the scratch field in small, predictable steps, and (3) controls heat and dust so clarity keeps improving rather than plateauing at a dull sheen.

Tools You’ll Need

• Random-orbital (DA) sander with variable speed; soft interface pad for minor crowns, firm backer for flats.
• Hand blocks: one firm (for flats) and one soft foam pad (for edges and gentle contours).
• Wet/dry silicon-carbide sheets: 80, 120, 180, 240 (dry) and 400, 800, 1200, 2000, 3000 (wet).
• Water + a drop of dish soap in a spray bottle (lubricant) and a rubber squeegee.
• Vacuum with brush head, microfiber towels, tack cloth.
• Raking/inspection light and pencil for guide marks; straightedge for flatness checks.
• Compounds and pads for final buffing (cut + finish); clean applicator cloths.
• PPE: respirator (P100), eye/ear protection, nitrile gloves, and good ventilation.

Recommended Grit Sequence

• 80 → 120 → 180 → 240 (dry): Flatten and refine without overheating. 80 only where needed to remove planer marks, ridges, or dust pimples.
• 400 → 800 → 1200 → 2000 → 3000 (wet): Clarity ladder that reduces time on compounds and leaves a uniform, easy-to-polish haze.

Step-by-Step: Flat, Clear, and Ready to Polish

1. Map the surface and protect edges. Under raking light, pencil a faint crosshatch across the top. Mask knife-sharp edges and live-edge bark you want to preserve. Guide lines show when each grit has done its job so you avoid extra cutting.
2. Reset only where necessary at 80 (dry). For ridges, planer marks, or stubborn dust nibs, make brief, overlapping passes at low speed with a firm backer—pad dead-flat, feather-light pressure. For a dependable starter sheet, stock 80 Grit (25-pack). Stop the moment the pencil map just disappears; don’t try to flatten the world with 80.
3. Refine at 120 → 180 (dry). Vacuum, wipe, then slightly change your pass direction (finish with the grain/flow). Replace all 80 tracks at 120, then all 120 at 180. Keep speed moderate; heat smears epoxy and loads paper. Use the firm block on flats and the soft pad only on minor crowns to avoid waves.
4. Pre-finish dry pass at 240. This tightens the scratch field before you switch to water. A short, even 240 pass erases 180 lines and leaves a uniform satin. If you need fresh stock for this exact step, grab 240 Grit (50-pack).
5. Set up for wet sanding. Flood the surface with a light film of soapy water. Keep a squeegee handy—wiping the slurry every minute lets you read the scratch field and spot any lows or leftover tracks before you climb grits.
6. Clarity ladder: 400 → 800 → 1200 → 2000 → 3000 (all wet). Work each grit with feather-light pressure and long, overlapping passes. At each step, squeegee often; you should see a progressively finer, even haze. If you can still find 240 scratches at 800, back up—don’t force it with pressure. Finish the ladder with a gentle 3000 pass for a fast polish; stocking a big box pays off here: 3000 Grit (100-pack).
7. Inspect, then buff. Rinse and dry with clean microfibers. Under raking light, the sheen should be uniformly dull-bright with no coarse ghosts. Compound with a cutting pad at low/medium speed until the haze clears, then follow with a finishing polish for full depth. Keep pads clean—contamination reintroduces scratches.
8. Edge & profile discipline. Remove tape and hand-sand edges lightly at your current grit (two strokes only). Most sand-through happens on edges; many pros skip sanding there and just polish.

Special Cases

Wood–epoxy transitions: Use a firm block while dry-sanding up to 240 so you don’t dish earlywood next to resin. Wet steps then blend everything visually.
Trapped dust or fisheyes in epoxy: Spot-level locally starting at 120–180 (dry), then re-enter the ladder. Don’t try to grind out deep craters with 400 wet; you’ll just polish the walls.
Soft, freshly cured pours: If epoxy gums at 240 dry or 400 wet, wait longer. Gummy resin smears and makes mystery scratches.
Inlays and live-edge bark: Hand-sand those zones and keep machines off uneven geometry; polish them separately if needed.

Pro Tips

• Flat backer = flat reflection. Foam is for crowns only; flats need a firm pad/block to avoid waves that halos will reveal under gloss.
• Read with a squeegee. Wipe the slurry often. If you still see directional 240/400 lines after an 800 pass, you’re not done—don’t climb yet.
• Fresh sheets beat pressure. The instant cut slows, rotate to a new quadrant. Pressure creates heat, smears epoxy, and prints swirls.
• Crosshatch, then finish with the flow. A small angle change at each grit reveals leftover scratches, then finish with the table’s visual flow for uniform reflection.
• Keep it cool & clean. Rinse sheets and surface frequently; one rogue coarse grain scratches everything.
• Don’t skip 240. It’s the bridge between shaping and clarity—skipping it makes 400 work too hard and leaves ghosts.

Aftercare

• Allow polish oils to flash, then seal (wax/sealant) per label; reapply protection as needed.
• Clean with pH-neutral soap and soft cloths; avoid abrasive pads that reintroduce swirls.
• Use coasters and felt feet—epoxy is tough, not scratch-proof.
• For a quick refresh months later, a light 3000 wet pass and a finishing polish restore clarity fast.

FAQs

• Can I start at 120 instead of 80? Yes—if your surface is already close. Use 80 only where defects demand it, then return to the ladder.
• Why do I see haze after polishing? Incomplete refinement. Revisit that area with 1200 → 2000 → 3000 wet, then compound lightly and finish polish.
• Do I need to wet-sand all the way from 400? For best clarity, yes. Dry steps are for shaping; wet steps are for optical refinement.
• What about Micro-Mesh above 3000? Optional. If you want ultra-gloss with minimal compound time, 4000–12000 works well—keep it wet and clean.
• My edges look dull. That’s normal if you protected them. Polish edges gently rather than sanding to avoid strike-through.

Watch & Learn

Closing: Crystal clarity comes from process, not pressure. Keep the ladder simple—80 → 120 → 180 → 240 (dry), then 400 → 800 → 1200 → 2000 → 3000 (wet)—and read the surface with a squeegee at every step. Stock the exact sheets so you stay disciplined: knock down defects quickly with 80 (25-pack), tighten the field before water with 240 (50-pack), and finish fast with 3000 (100-pack) before a quick cut-and-polish. Do that, and your river will look like liquid glass.