By Show Me Step by StepPublished
Based on a video by ResinObsession.
Resin jewelry rarely comes out of the mold ready to wear. Resin creeps up the mold walls and leaves a sharp lip, or you overpour and end up with a thin skirt of resin around the piece. Katherine from Resin Obsession shows how she cleans up a set of cast earrings with wet sandpaper, kitchen shears, a flex shaft and a couple of small files.
The same method works on pendants, charms, keychains and coasters.
Dry sanding throws fine resin dust into the air, and you do not want to breathe it. Water traps the dust as a slurry. It also keeps the surface cool, so the dust does not melt back onto your piece and smear. Use wet/dry sandpaper, the black or grey kind sold at hardware and auto parts stores. Ordinary paper sandpaper falls apart once it is wet.
Never skip more than one grit. Deep scratches from a coarse paper will still show under a fine one.
Sanding leaves resin cloudy. That is normal. To bring the shine back you have three options. Keep working up through the grits to 2000 or 3000, then rub on a plastic polishing compound with a soft cloth. Or brush a thin top coat of resin over the sanded area, which fills the scratches and cures glossy. For small pieces, a quick coat of clear gloss spray also works. Rinse and dry the piece before any of these.
Wear safety glasses and a dust mask any time you use a rotary tool on resin. Sand on a tray or an old baking sheet, and keep tools you use for resin away from food prep. That includes the kitchen shears.
Flat spots or a lopsided edge come from sanding one side at a time. Keep the piece moving and turn it as you go. Little half moon dips on an inner edge mean the rotary tool sat in one place, so keep it moving too. White haze that will not go away usually means you skipped grits. Go back one grit and work up again. If the resin feels soft or gummy while sanding, it has not fully cured; leave it another day or two.
Coasters and trays follow the same order, only larger. Tape the sandpaper to a flat board so it does not slide, and sand the edges with the piece standing on its side. A sanding block keeps the edge square. Rinse between grits so a stray coarse grain does not scratch your finer work.
Pour slowly and stop a little below the rim of the mold. A slight dome from surface tension is fine. Overfilling is what causes the lip.
New to resin? Start with how to mix epoxy resin and use resin molds, then try resin earrings. If a piece cures tacky, see how to fix sticky resin, and for a glossy finish on top, dome it with resin.
9 steps · about 7 minutes.Check off each step as you go and your progress saves automatically.
Run a finger around each piece once it has fully cured. Look for a raised lip where resin crept up the side of the mold, or a thin skirt where you overpoured. These edges can be sharp enough to scratch your neck. Decide how much you want to remove. A light pass takes the edge off; more work can reshape the piece.
Tip
Sand only fully cured resin. Soft resin clogs the paper and tears instead of sanding.
Lay a sheet of 400 grit wet/dry sandpaper on a flat surface and wet it well. Put the earring face down on the paper and move it in small circles with light, even pressure. Change direction now and then and rotate the piece. Sanding flat like this takes the same amount off all the way around.
Tip
Keep a cup of water nearby and splash the paper whenever it starts to feel dry.
Pick the piece up every few circles and look at the edge. Compare it to one you have not sanded yet. Resin is soft, so it changes fast. Stop when the ridge is gone and the edge feels smooth to your finger. If you want a finer finish, move on to 600 grit and repeat the same circles to remove the 400 scratches.
Tip
Wipe the slurry off before you judge it. Wet resin looks clearer than it really is.
When a casting has a wide skirt of extra resin, sanding it all away takes forever. Cut most of it off first with heavy duty kitchen shears. Work around the piece in short snips and get as close to the edge as you can without cutting into the shape itself. Thin overpour cuts like stiff plastic.
Tip
Shears used on resin stay in the craft room. Do not use them for food again.
Shears leave a sharp, choppy edge, so go back to the wet sandpaper. Press the piece on the paper and turn it as you sand, instead of sanding one spot and then turning. Sanding in one place leaves flat facets, like a stop sign. A few strokes remove a lot, so check often.
Tip
Hold the piece by its face, not its edge, so your fingers do not catch on the paper.
Lift the ring and look all the way around. The outer edge should now be even and smooth. You may still see rough bits on the inside of the ring where the paper cannot reach when it lies flat. For a small amount, fold a strip of wet sandpaper and work it around the inner edge by hand.
Tip
Tilt the piece toward a window. Raking light shows bumps your fingers miss.
Put on safety glasses and a dust mask first. Fit a split mandrel with a strip of 600 grit sandpaper to a flex shaft or rotary tool. Hold the handpiece in your palm and brace it with your thumb. Run the spinning paper lightly along the inside edge and keep the ring turning so you do not dig half moons into it. Let the tool do the work.
Tip
No flex shaft? A Dremel with a small sanding drum does the same job.
For one stubborn bump, a heavy duty nail file from a beauty supply store is often quicker than getting a tool out. Hold the piece steady and file in short strokes on that one spot. Check after every few strokes. It is easy to take off more than you meant to on a small piece of jewelry.
Tip
Coarse emery boards work too, but they wear out quickly on resin.
Diamond needle files have tiny diamonds bonded to thin steel shafts, so they reach into narrow cracks and inner curves. Slide the file along the rough spot with light pressure. They cut fast, so a few passes are usually enough. When you are happy with the shape, rinse the piece and move on to polishing.
Tip
Dip the file in water now and then to keep resin dust from loading up the diamonds.
Keep going
How to Remove Bubbles from Epoxy Resin
How to Sand Resin Jewelry and Polish the Edges
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