Traditional Kintsugi with Urushi and Gold

Pick your fork before you buy anything

Two honest paths, and neither one is the fake one

One question decides which path you are on

Almost everything sold as a kintsugi kit is one of these two things. They are not the same craft wearing different hats. They produce different objects, on different timescales, with different rules about what you are allowed to eat off afterward.

Every comparison of traditional and synthetic kintsugi is really one question wearing a lot of clothes: are you going to eat or drink off this pot?

• Yes, it goes back in the cupboard

  Traditional urushi. Two months, a real skin hazard while you work, and a repair that is genuinely food safe and will outlive you. There is no shortcut version of this that is also safe to eat off.

• No, it lives on a shelf

  Synthetic. Two-part epoxy and mica powder, done in an evening, no lacquer rash. Treat it as decorative, keep it off drinking rims, and enjoy it for exactly what it is.

Neither column is cheating. What is cheating is selling a synthetic repair as food safe, or letting somebody eat off an epoxy seam because it looks like gold. The rest of this page teaches the left column first and then the right column properly, because most people should probably start on the right.

The shopping list

What you actually need, and what the words mean

The vocabulary is the barrier, not the technique. There are really only three lacquer mixtures in this whole craft, and each one is raw urushi plus one other thing. Once that lands, the rest of it is patience.

All of this is bring-your-own. The studio does not stock urushi, gold powder or any part of a kintsugi kit, and we have no plans to. Buy a kit from a Japanese maker rather than assembling it yourself the first time. The proportions in a kit are already right and getting them wrong is how a repair fails in month two.

Buy a starter kit from a Japanese maker rather than assembling one yourself. The proportions are already right, and getting them wrong is how a repair quietly fails in month two. Add plain wheat flour, ethanol, vegetable oil, wet and dry sandpaper, masking tape and a box of nitrile gloves from your own cupboard.

The three mixtures, decoded

On top of those three you use two coating lacquers. Black urushi, the middle coat that gets sanded flat and gives the gold something even to sit on. And bengara urushi, a red-brown lacquer, which is the last wet layer and the one the metal powder actually lands in.

Plus two coating lacquers: black urushi for the middle coats, and bengara, a red-brown, for the last wet layer that the metal lands in.

The kit list

• Raw urushi The base of everything. Refrigerate it, use it within about a year.
• Black urushi and bengara urushi The two coating lacquers.
• Tonoko and wood powder The fillers you mix into sabi and kokuso.
• Metal powder Pure gold, silver, platinum or brass. See the gold section below.
• Wheat flour Plain flour from your own cupboard. It has to contain gluten, so most gluten free flours will not work.
• Spatulas Cypress or plastic, for mixing and applying paste.
• A menso brush A very fine lacquer brush for the final line.
• An ashirai brush or a soft dusting brush For laying down metal powder.
• A silk ball Wadded silk. This is what you burnish the gold with.
• Wet and dry sandpaper Roughly 400 up to 1500 grit.
• A small file or craft knife For carving back hardened squeeze-out.
• Masking tape Not optional. This is what stops gravity undoing your glue-up.
• Ethanol For degreasing the break and cleaning tools.
• Vegetable oil For getting urushi off skin and off brushes.
• An acrylic sheet or glass tile Your mixing surface.
• Nitrile gloves A box of them. You will change them often.
• A cardboard box This becomes the curing box. Next section.

Two words you will meet in catalogs. Keshifun is fine matte metal powder, the beginner default, and it needs no polishing. Marufun is a coarser round powder that gives a deep mirror finish and has to be burnished and consolidated. Start on keshifun.

The traditional path

Six stages, and five of them are mostly waiting

Six stages, and one video to work from

Here is the whole method in one place. Each stage has a short list you can work from and video of somebody doing that exact stage. Work down the page in order and do not skip a cure, however tempting it looks.

Do these in order and do not skip a cure, however tempting it looks. Every wait below is in the damp box.

1. Clean, dry-fit, tape

   Wash the break faces, degrease with ethanol, dry the pot for a day. Assemble it dry with tape first to work out the order the pieces go in, and cut your tape strips before you mix anything. Grease left in the break is why repairs let go months later.

2. Glue with mugi urushi, then wait two weeks

   Smooth flour paste, then an equal volume of raw urushi folded in until the color is uniform. Thin film on both faces, press, tape under tension across every join, wipe the squeeze-out with an oiled cotton bud while it is wet. Box for one to two weeks.

3. Fill any gaps, then smooth them

   Only if there is a chip or a missing piece. Kokuso putty packed slightly proud for volume, in layers rather than one thick plug. Then two or three rounds of sabi urushi, wet sanded back at 600 grit between each, until a fingernail does not catch on the seam.

4. Two or three black urushi coats

   A lightly loaded fine brush, one smooth pass along the line, cure, then a very light wet sand at 1000 to 1500 grit. Repeat. This stage is what separates a repair that looks professional from one that looks homemade.

5. Bengara, wait for tacky, dust the metal

   Paint a thin red-brown line, then wait somewhere between fifteen minutes and two hours until it is tacky rather than wet. Paint the same line on a scrap shard at the same time and use it as your timer. Tap the powder on with a soft brush, do not paint it on.

6. Cure a week, burnish, then wait a month

   Brush the loose excess away, box it for a week, then burnish gently with a silk ball. Keshifun needs almost nothing. Wait a further month before you eat off it.

Keep this video open on your phone while you work. It is the whole method, food safe, in one sitting.

Stage 1. Clean and prepare the break

Nothing sticks to grease. This stage feels skippable and is the single most common cause of a repair that lets go three months later.

• Wash everything Warm water, dish soap, a soft brush into the break faces. Old pots carry decades of oil.
• Dry it completely A day in a warm room. Trapped water in a porous body will fight the lacquer.
• Wipe the break faces with ethanol Both sides of every join.
• Dry-fit before you mix anything Assemble the whole pot with masking tape and no glue. Work out the order the pieces go in. A three-piece break has a right order and a wrong one that locks you out.
• Number the pieces Small pencil marks on the inside. You will be glad an hour later.
• Cut your tape now Strips ready on the table edge. You do not want to be tearing tape with lacquered gloves on.

Stage 2. Glue with mugi urushi

Mugi urushi is flour, water and raw urushi. It is the glue, and it is strong enough that a properly done join will break somewhere else next time.

• Make a flour paste first A little plain flour, water added drop by drop, worked with a spatula until it is smooth and about the thickness of toothpaste. No lumps.
• Add raw urushi in roughly equal volume Fold it in on the acrylic sheet, scraping and folding, until the color and texture are completely uniform. Streaks mean it is not mixed.
• Apply a thin film to both faces Thin. A visible bead of glue is too much and will squeeze out into a ridge you have to carve off later.
• Press and hold Line the pieces up by feel, not by eye. Run a fingertip across the join through a glove. Level beats visually straight.
• Tape it under tension Strips across every join, pulling the pieces together. Gravity will open a join overnight if you let it.
• Wipe squeeze-out now A cotton bud with a little oil, while it is still wet. Ten seconds now saves twenty minutes of carving later.
• Into the box for one to two weeks Yes, weeks. Mugi urushi is slow and rushing it here undoes everything after it.

Stage 3. Fill the volume with kokuso

Only if you have a chip or a missing piece. A clean break with no losses skips straight to stage 4.

• Carve back the hardened squeeze-out first A craft knife held almost flat, working along the join rather than across it. Gloves on: this dust is the classic way people get a rash weeks in.
• Mix kokuso Raw urushi, a little mugi urushi, and fine wood powder until it is a stiff putty that holds a shape.
• Pack it in slightly proud Press it into the gap and leave it a touch above the surrounding surface. It shrinks a little as it cures.
• Shape it while it is soft A wet spatula gets you most of the way to the pot’s real curve. Every minute here is five minutes of sanding saved.
• Build big gaps in layers Never one thick plug. Two or three thinner passes with a cure between each.
• Cure three to seven days per layer Back in the box.

Stage 4. Smooth it with sabi urushi

Sabi is the fine filler. It closes hairlines, pinholes and the texture kokuso leaves behind, and it is what turns a structurally sound repair into a smooth one. Everybody underestimates how many rounds of this it takes.

• Slake the tonoko Tonoko powder with just enough water to make a stiff clay-like lump. Let it sit a few minutes.
• Add raw urushi Work it in until it is uniform and about the consistency of soft butter.
• Skim it along the seam A spatula almost flat, pressing it into the line and scraping the excess off. You want it in the gap, not spread across the glaze.
• Cure two to four days Box again.
• Wet sand back 600 grit or so, with water, working only the fill and staying off the surrounding glaze. Gloves, and rinse the slurry away rather than letting it dry into dust.
• Repeat until it is genuinely flat Two or three rounds is normal. Run a fingernail across: if it catches, it is not flat.

Stage 5. The black coat

Black urushi is the middle coat. It seals the fill and gives the gold a hard, even bed to sit on. Gold laid straight onto sabi looks dull and patchy, because sabi is porous and drinks the lacquer under it.

• Load the menso brush lightly Wipe most of it off. A loaded brush floods the line.
• One smooth pass along the seam Follow the line, do not scrub back and forth. Slightly wider than the fill, so the seam reads as a deliberate line.
• Cure one to three days Box.
• Wet sand at 1000 to 1500 grit Very light. You are flattening, not removing.
• Coat and sand again, two or three times The line should end up glassy. This is the stage that separates a repair that looks professional from one that looks homemade.
• Clean the brush in oil immediately A dried menso brush is a dead menso brush.

Stage 6. Bengara, then the metal

The last wet layer is bengara urushi, a red-brown lacquer. The metal powder does not get glued on afterward. It gets dusted into the bengara while it is still tacky, and the lacquer grabs it. Timing is the whole skill here.

• Paint a thin bengara line Same technique as the black coat, one clean pass.
• Wait for tacky, not wet Put it in the box and check it. Somewhere between about 15 minutes and two hours depending on humidity and the lacquer. Too wet and the powder sinks and goes dull. Too dry and it will not hold at all.
• Test on a scrap first Paint a spare line on a broken shard at the same time and use it as your timer. This one habit saves more first attempts than anything else on this page.
• Dust the powder on A soft brush or silk ball, tapped over the line like tapping ash off a cigarette. Do not paint it on.
• Cover it fully, then stop Once the line is covered, adding more does nothing but waste gold.
• Back in the box for 30 minutes to two hours Then brush the loose excess away gently with the tip of a dry brush.
• Cure a week, then burnish A silk ball, light strokes. Keshifun needs almost nothing. Marufun needs real burnishing over several sessions.

The same six stages, in one sitting, from a second teacher

Two teachers is better than one. Chimahaga is a Tokyo repairer whose full walkthrough covers a broken pot end to end with the same food safe method, and hearing it explained twice by different people is what makes it stick.

The expensive part

Gold, and the four decisions nobody warns you about

• Keshifun or marufun

  Keshifun is fine and matte, sits down evenly, needs no polishing, and is right for a first repair. Marufun is coarse and round, has to be burnished and consolidated over several sessions, and gives the deep liquid mirror you see on museum pieces. Marufun is a skill; keshifun is a technique.

• Which metal

  Pure gold never tarnishes and is inert. Silver is cheaper and beautiful and will darken, which some people want. Platinum gives silver’s color without the tarnish. Brass is the budget option, looks close to gold at first, oxidizes over years, and should be kept away from food surfaces.

• How much you need

  Far less than feels right. A tenth of a gram covers a surprising length of seam. Kits ship that quantity for a reason. Most beginners waste half their gold on the first pass by loading the brush and painting instead of tapping and dusting.

• Whether to use metal at all

  A repair finished in plain black or red lacquer with no metal is a real, traditional, complete result. It has its own name and its own following. If the gold is what is stopping you starting, skip the gold and start.