Reported practice · r/Kintsugi

Kintsugi repair sequence and troubleshooting dull gold-powder finishes

A practitioner presents three completed or in-progress kintsugi repairs (a teacup, a teapot lid, and a small bowl) and the thread develops into a detailed discussion of how to achieve a bright, durable finish when using fine versus coarse gold powder, and what to do when the result looks flat and lifeless.

This page is written from one discussion thread. It records what practitioners reported and what they linked it to — not documented workshop practice. Every claim below links to the comment it rests on, so you can read it in context.

Safety

Raw urushi (ki-urushi) and its mixed preparations (mugi-urushi, sabi, e-urushi) are potent skin sensitisers. Contact can trigger a delayed urushiol-type dermatitis that may appear 24–72 hours after exposure and can persist or recur with subsequent contact. Gloves that are not permeable to the sap, and careful removal of contaminated rags, are essential.

What the thread establishes

The answer.

The thread establishes that the coarser round powder (marufun), once polished or burnished, produces a more wear-resistant final surface than the finest powder (keshifun) applied as a top layer. For keshifun to show its characteristic soft, pearlescent reflectivity, the underlying ground must be perfectly level, the adhesive lacquer coat must be applied at the thinnest workable thickness and kept free of any foreign matter, and the coat should be allowed to reach a uniform partial-cure tack before the powder is sprinkled. An alternative technique is to thin a gilding-grade lacquer with turpentine, camphor, or ethanol to produce an ultra-thin film, let the solvent flash off, and apply the powder to the resulting tacky surface. For the specific repairs shown, the practitioner beveled crack edges, used raw lacquer or wheat-flour lacquer for adhesion, filled with sabi putty, applied iron-oxide lacquer as the powder bed, and finished with #1 marufun—polishing the glazed teacup and burnishing the porous teapot lid to avoid staining the glaze with abrasive residue.

What goes wrongGold powder applied as a final decorative layer appears flat, matte, or dull rather than showing the expected metallic or pearlescent luster. Unpolished marufun in particular reads as a lifeless brown with no reflective quality. The practitioner in the thread reports that despite following basic instructions, the keshifun consistently looks lackluster.

What recovers itVerify that the substrate beneath the powder is free of scratches, ridges, or depressions. Re-apply the adhesive lacquer at the minimum thickness that will hold the powder, ensuring no dust or debris is trapped in the film. Allow that coat to cure to an even, uniform tack—neither still wet nor fully set—before sprinkling. If the problem persists, switch to a solvent-thinned gilding lacquer to achieve a thinner, cleaner adhesive film, and apply the powder once the solvent has evaporated and the surface is tacky.

01

Prepare the ground for fine gold powder

Sand or polish the substrate beneath the final gold layer until it is as level and unblemished as possible. Any residual scratch, ridge, or depression will scatter light and reduce the reflectivity of the powder.

02

Apply the adhesive lacquer at minimum thickness

Lay down the urushi coat that will hold the powder at the thinnest workable film, and ensure it is entirely free of dust, lint, or other foreign particles. Excess lacquer or contamination will cause the powder to aggregate and lose its luster.

03

Cure the adhesive to a uniform tack

Allow the lacquer coat to enter a partial cure before sprinkling the powder. The target state is an even, consistent stickiness—neither still liquid nor fully set. If the coat is too wet, the powder will ball up. Experiment with humidity and time to find the right window.

04

Alternative: solvent-thinned gilding lacquer

Thin a gilding-grade urushi preparation (a formulation historically used for adhering gold leaf) with turpentine, camphor, or ethanol to produce an extremely thin film. Apply the gold powder once the solvent has flashed off and the surface has returned to a tacky state.

··Reported

What was reported

  • A hairline crack in a teacup attributed to a kiln firing fault rather than mechanical impact can be repaired by beveling the edges, infilling with raw lacquer followed by sabi putty, and finishing with iron-oxide lacquer and #1 marufun gold; the repair held without failure over a decade.
  • When the repaired vessel has a porous glaze, burnishing the gold powder is preferable to wet polishing because abrasive polishing compounds can stain or mark the glaze surface.
  • For a teapot lid with a drop crack, the practitioner beveled the edges, adhered the halves with wheat-flour lacquer, filled with sabi, and finished with iron-oxide lacquer and #1 marufun, burnished rather than polished.
  • A large chip in a small bowl whose fragments were too small and pulverized to reassemble presents a choice between a simple wood-dust filler (kokuso) or a more robust layered build-up of hemp, fired-clay powder, charcoal, and fine polishing clay.
  • Polished or burnished marufun is more durable as a final decorative layer than keshifun applied without further finishing.
  • Keshifun left unburnished produces a soft, matte, pearlescent sheen; marufun polished yields a solid metallic luster; marufun burnished gives a glittery luster; and marufun left entirely unworked reads as a flat brown with no reflectivity.
  • The practitioner's background in urushi work (wood finishing, maki-e, raden on small objects) preceded and informed the kintsugi practice, and initial learning relied heavily on reading Japanese-language sources, watching limited video material, and extensive self-directed experimentation.
  • Synthetic whetstones in 2000 and 3000 grit, identical to those sold by a Japanese urushi supplier, are available domestically in the United States through Japanese knife retailers.
  • A Japanese urushi supplier (Watanabe Shoten) carries a broader range of tools and materials than the Mejiro brand the questioner had been using.
  • The teapot lid being repaired is of a shape the original maker no longer produces, making the repair the only way to retain the vessel in a usable form.

Limits of this source

What the thread does not answer.

  • The bowl chip repair is undecided: the practitioner has not yet chosen between a simple kokuso fill and the more labour-intensive layered build-up of hemp, jinoko, charcoal, and tonoko.
  • The keshifun troubleshooting advice in the thread is cut off mid-sentence, so the final tip the practitioner intended to give is lost.
  • The questioner's difficulty finding suitable polishing stones and other supplies in the United States is only partially addressed; the whetstone question is answered but the broader supply-chain problem remains open.
  • Whether the dullness the questioner experiences with keshifun is ultimately a technique issue, a powder-quality issue, or both is not resolved; the practitioner offers procedural fixes but does not confirm the questioner's specific cause.
Read the documented methods