# The Repair Hewn Shop Notes · https://hewn.build/shop-notes/the-repair AI-drafted, not yet checked: Drafted by Chip, the writing system Hewn runs on Claude, from Hewn's craft corpus. Jonathan Salomons has not read this note yet, and no outside reader has checked it. Read it as a shop note: check a number before you cut to it. Cite as: "The Repair." Hewn Shop Notes, hewn.build/shop-notes/the-repair. Drafted 2026-05-02; AI-drafted, not yet checked. --- The first thing you notice about a repair job is how much you don't know. New builds are clean. You chose the species, watched the moisture content come down to 7 or 8 percent, cut the joints, mixed the glue, applied the finish. Every decision is yours. If something goes wrong, you know where to look. Repair starts in the middle of someone else's story. That's harder. It's also where you really learn. The piece in front of you has a history — maybe twenty years, maybe eighty. Humidity swings it never fully recovered from. A finish that might be oil, might be varnish, might be something they stopped making before you were born. Joinery that was cut well or badly, and you won't know which until you get in there. Your job is to read what you're looking at, work backward to understand what happened, then figure out what to do now. Old pieces teach things that years of new work can miss. Consider a quarter-sawn white oak case, old growth, with a panel that had moved nearly 3/4 inch in each direction every year for decades, locked in a frame with nowhere to go. The damage is obvious. The cause is a geometry problem built in at the start. The builder did fine joinery on a structurally flawed plan, and the wood was patient about proving it. That's what repair gives you. The piece is evidence. The failure tells you something about how things fail. --- **Three categories.** **Structural.** Joints, frames, corner blocks, support elements. The piece looks fine but something has let go. Most structural failures trace back to a glue line. Most glue line failures are predictable once you understand what load the joint was carrying and what the material does under stress. **Surface.** Finish damage — scratches, watermarks, worn areas, crazing, peeling. The structure is sound. The surface isn't. The question is whether you can repair the surface without disturbing what's underneath, and whether you can match what's there. The second question is usually harder than the first. **Seasonal.** The wood moved, and the build didn't accommodate it. Split panels. Racking cases. Breadboard ends that pulled free. The damage is visible now. The cause was set in place years ago by someone who either didn't know the math or didn't believe it applied. These take the most diagnosis, because you're not just reading the failure — you're reconstructing the conditions that produced it. --- **Diagnosis first.** A repair started without a diagnosis is a guess. Guesses occasionally work. They also occasionally make things worse. From there: the three failure types. Then the inherited piece — the one that arrives with no documentation, no history, no record of species or finish or what happened or when. That's its own discipline. The through-line is the same as every build: preparation is the work. In repair, preparation means reading the failure before you pick up anything. Not in general terms. Specifically, in the piece in front of you. --- Some of the best work you will ever handle comes through the door as a repair job. Old growth, hand-cut joinery, a finish system applied by someone who knew what they were doing. What you carry back to the bench from that is worth more than the repair fee. Every failed joint is a mechanics lesson with real answers. Every split panel is a wood movement equation with the variables already filled in. You stop guessing at cause and start reading it. That's the skill repair teaches. Monday's a good day to start.