# The Fit Hewn Shop Notes ยท https://hewn.build/shop-notes/the-fit-74 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 Fit." Hewn Shop Notes, hewn.build/shop-notes/the-fit-74. Drafted 2026-04-22; AI-drafted, not yet checked. --- The joint doesn't close on the first try. If yours does, you're either very lucky or very slightly off somewhere you haven't found yet. Either way, plan for iteration. This is fitting. It's different from cutting. Cutting is committing the geometry. Fitting is listening to what you committed. --- The diagnostic tool is chalk. Blue chalk on light wood. Pencil graphite on dark species where chalk disappears into the grain. Rub it across the faces and edges of the tails. Slide the joint together under hand pressure โ€” not mallet, not body weight, hand pressure. Where it stops is information. Pull it apart. Look at the pin sockets. The chalk has transferred to the high spots, the places where the tails made contact before the joint fully seated. Those marks are the problem. Everything else is not. This is the only thing you pare. Not what looks suspicious. Not what seems like it might be an issue. The chalk mark, and nothing else. Work the long walls of the pin sockets. Pare toward the baseline, not through it. That baseline is the hardest commitment in the joint โ€” breach it and the shoulder can't seat. You're easing a contact point, not re-cutting the shape. Keep the chisel flat against the socket wall. Light passes. A sharp chisel only. Then: wipe the chalk off the tails. Reapply. Fit again. That's the cycle. Chalk, fit, read, pare, repeat. You're converging on a specific answer, not estimating your way to something approximate. --- The target is a joint that closes under firm hand pressure. Tails fully seated against the pin board, baseline flush against the end grain, no light at the shoulders. When that happens, stop. The temptation is familiar. You want a little more clearance, a little insurance for glue-up day. Here's the problem: glue swells wood. A joint that needs a mallet dry will not close under glue. Every pass after hand-tight is removing precision you already earned. You're not building in forgiveness. You're introducing slop. Stop when it closes by hand. --- A few things go wrong in the fitting. Gap at the baseline after assembly: you pared through a high spot into a low spot. Light enters the shoulder where it shouldn't. Prevent it with more chalk iterations and less aggressive passes. Once it's there, you're refinishing that face. Joint racks during assembly โ€” closes tight on one side, loose on the other: go back to the transfer. If the tail board drifted even one degree during scribing, you get asymmetric contact. The chalk will show it. One side fully marked, one side barely touched. Ease the side that's marking early. Joint won't close at all after multiple passes: check the baseline on the tail board itself. A baseline that stops short on one face means the tails can't fully seat. Re-cutting the baseline is the fix, and it's harder than anything you just did fitting the joint. --- The chalk shows you where the joint is thinking. Your job is to agree with it, one pass at a time, and stop the moment it stops asking for more.