# The Season

Hewn Shop Notes · https://hewn.build/shop-notes/the-season

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 Season." Hewn Shop Notes, hewn.build/shop-notes/the-season. Drafted 2026-05-01; AI-drafted, not yet checked.

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Nobody tells you upholstery is temperature-dependent. The books are written from temperate coastal shops or heated commercial workrooms. Those writers have never done this in a BC Interior shop in March where the stove has been off since Thursday night.

Temperature isn't a comfort issue. It's a performance threshold. Below certain numbers, materials behave differently — not slightly worse, but wrong.

Here are the numbers.

**Contact cement** — foam to frame, gimp, trim — needs 16°C. Both surfaces and ambient air. Below that, solvent evaporation slows, open time goes unpredictable, bonding requirements change. Cold-bonded joints pass visual inspection and fail at the first flex load. That's a post-delivery problem.

**Water-based fabric adhesive:** 15°C minimum. Cold-applied adhesive can bond without full penetration. Looks fine. Fails under tension when the cover gets pulled tight.

**Fabric layout and cutting:** 15°C. Cold woven fabric has residual memory from storage. It won't lie flat, and it won't read grain accurately until it's relaxed to room temperature. For pattern matching, that's a cutting error in progress.

**Leather:** 16°C before you bend it to mark or cut. Below that, chrome-tanned hides lose elasticity and can surface-crack at sharp fold lines. You won't see it at the bench. You'll see it in a photograph the client sends six months later.

**Foam:** No hard floor for handling, but foam stored below 5°C needs two to four hours to return to working memory. Cut it cold and the dimensions are accurate. Wait for it to warm up and the dimensions are different. Cut after acclimation. This one surprises people.

The scheduling implication is straightforward. You stop improvising and start planning. Cold-tolerant operations — stripping, frame inspection, foam rough-cuts, spring work — go when the shop is still cold. Temperature-sensitive work — adhesive application, fabric layout, leather — goes after the shop has been at temperature long enough to be stable throughout. Not just at the heater. Throughout.

It's the same discipline you already use for finishing. The finishing area needs temperature control through the first cure phase. Upholstery is the same trade-off. The cover is a finish. The conditions it's applied in determine how long it holds.

One thing the cold shop has going for it: BC Interior winter air is dry. Lower humidity means faster tack in solvent-based adhesives and no humidity-related problems in water-based ones. The cold shop's limitation is temperature. Its advantage is humidity. Know which operations benefit and schedule accordingly.

The season governs this. Build around it.