19 May 2026

A water-stained saya

I began by checking the fit: blade in and out, koiguchi, and whether the seam had opened. If the wood has swollen, forcing the blade is the main risk, so I let it dry slowly in a stable room, away from a radiator.

For the finish, I used a mild abrasive only at the edge of the lifted lacquer, not across the bare wood. Where the stain sat in the wood, I left most of it; sanding would change the shape and the fit. A thin touch-up was enough to stabilise the area.

The piece left with the patina it had earned and a note to keep it away from damp. Not every mark needs to be removed. Sometimes the better repair is to stop the damage and leave the history.