Material guide
Resin & epoxy
What works on cured epoxy and resin: when it's ready to drill, how to cut and sand it, how to make new epoxy stick, and how to handle the dust.
Quick facts
- Ready to work
- Wait for a full cure. ArtResin lists 24 hours to hard and 72 hours to full. Check your resin's sheet.
- Best drill bit
- A small twist bit first, then step up in size. Keep holes away from the edge.
- Glue to cured epoxy
- Wash off amine blush with water, then sand glossy spots with 80-grit
- Sanding grits
- 80 to 120 to scuff between coats. 320, 600, then 1500 wet for a smooth matte finish.
- Dust
- Dust from partly cured epoxy raises your risk of an allergy. Wear an N95 mask.
- Skin
- Wear gloves with uncured resin. Stop work if a rash starts.
Epoxy resin starts as two liquids, a resin and a hardener. Mix them and they react and turn into a hard plastic. Crafters pour it into molds and over art. Woodworkers fill gaps and coat tabletops with it. Boat builders glue and seal with it.
Most problems come from timing. Resin goes from liquid to gel to rubbery to hard, and it keeps getting harder for days. Drill or sand too soon and it smears, tears or gums the tool. The dust from partly cured resin is also more likely to give you a skin allergy.
Once it's fully cured, epoxy is easy to work. It drills, cuts and sands like a hard plastic. Go slow so it doesn't heat up, and keep holes away from thin edges, where it chips.
To add more resin later, prep the old surface first. A waxy film called amine blush can form on top as it cures. Wash it off, then sand, and the new coat will bond.
Drill into resin & epoxy
Cured resin drills well, but wait for the full cure. Start with a small bit and drill all the way through, then step up to the size you want. Stay away from the edge and wear a dust mask. For tiny holes, a pin vise works.
What to use: Small twist bits + pin vise
Guides
- How to make a hole in resin without a drill
- How to drill resin and epoxy castings cleanly (coming)
Cut resin & epoxy
Once fully cured, resin cuts like a hard plastic. Use a fine-tooth saw, scroll saw or band saw, and clamp the piece. Feed slowly so the blade doesn't heat up and gum. Sand the cut edge after.
What to use: Fine-tooth blade + clamps
Guides
- Cut cured epoxy and resin castings (coming)
Glue resin & epoxy
New epoxy sticks to cured epoxy if you prep it. Wash the surface with clean water and an abrasive pad to remove amine blush, a waxy film. Let it dry, then sand glossy spots with 80-grit. If the old coat is still tacky, you can pour over it without sanding.
What to use: Abrasive pad, water, 80-grit paper
Guides
- Will new epoxy stick to cured epoxy? (coming)
- Epoxy still sticky after 24 hours: causes and fixes (coming)
- How long does epoxy take to dry (and why it stays tacky) (coming)
- Minimum temperature for epoxy and glue to cure (coming)
- Remove dried epoxy from tools, floors, and skin (coming)
Screw or anchor into resin & epoxy
For a hanger or jump ring, mold the hole in before you pour. In a cured piece, drill a hole and glue the hardware in with epoxy, so the load spreads. Keep holes well away from edges, where resin chips.
What to use: Mold-in hole or epoxy-set hardware
Sand or finish resin & epoxy
Scuff between coats with 80 to 120 grit. For a smooth matte finish, wet sand with 320, then 600, then 1500 grit. Move up only when the scratches are gone. Bring back the gloss with a thin coat of resin or a polishing compound.
What to use: Wet-or-dry paper + polishing compound
Guides
- Sand and polish epoxy resin (wet-grit sequence) (coming)
- Sandpaper grit chart: which grit for which job (coming)
Safety basics
- Wear nitrile gloves. Uncured resin and hardener can give you a lasting skin allergy. Stop if a rash starts.
- Wear an N95 mask and glasses for dust. Sand wet when you can, and wait for a full cure before you sand.
- Air out the room. Work with a window open or a fan, especially in a small space.
- Don't burn or melt it. Heating cured epoxy gives off smoke you shouldn't breathe.
Sources
- ArtResin technical data sheet: hard cure 24 h, full cure 72 h (ArtResin)
- Can I drill into ArtResin after it cures? Fully cured resin is machineable; small bit first; not near the edge; dust mask (ArtResin)
- How to sand epoxy resin: 80-120 grit between coats, 320-600-1500 wet, N95, glasses, gloves (ArtResin)
- Surface preparation: wash amine blush with water and an abrasive pad, sand glossy areas with 80-grit (WEST SYSTEM)
- Epoxy resin and hardener basics: cure stages (Epoxyworks, WEST SYSTEM)
- Preventing overexposure: gloves, eye protection, stop if you react, partly cured dust raises sensitization (WEST SYSTEM)
- Common shop dusts: partially cured epoxy dust, wet sanding, ventilation (WEST SYSTEM)