Making Woodworking Joinery Finishing And Upholstery

---
name: making-woodworking-joinery-finishing-and-upholstery
description: "Use when building or repairing furniture: wood movement with moisture content and seasonal dimensional change and why ignoring it splits panels, joinery and which joints resist which forces, adhesives and fasteners, wood finishing from oils to film finishes with surface preparation, upholstery with foam, webbing and springs, and seating geometry and frame construction."
---

# Fabric, Clothing and Furniture: Wood Movement, Joinery, Adhesives and Fasteners, Wood Finishing, Upholstery, and Seating and Frames

> **Part 3 of 5** of the *Making Fabric, Clothing and Furniture — and Caring for Them* reference (plugin `making-fabric-clothing-furniture-laundering`), covering §16–§21. Sibling skills: `making-fibres-yarn-weaving-knitting-and-dyeing` (§0–§7), `making-garment-drafting-seams-and-construction` (§8–§15), `making-laundering-stain-removal-care-and-mending` (§22–§26), `making-reference` (§27–§32). Section numbers are shared across the set; a reference written as §N → `skill` points into that sibling skill.
>
> **Currency:** The crafts are centuries old and stable. Two areas moved. See §27 → `making-reference` for microfibre shedding and filter regulation, and PFAS restrictions in textiles and furniture.

> **⚠️ Four crafts unified by one principle: the MATERIAL'S behaviour determines
> everything downstream.** ⚠️ **Fibre decides yarn, which decides fabric, which decides
> what garment is possible and how it must be washed.** **Wood species and grain decide
> joinery, which decides what will survive a winter of dry indoor air.** **⚠️ Almost every
> failure in this document is someone fighting the material instead of designing with it.**
>
> **Complements a cooking/cleaning/waste reference (surfactant chemistry and disinfection
> in general), and a materials or thermo reference for the underlying physics.**
>
> **⚠️ GOTCHA** boxes mark the received wisdom that's wrong, and the mistakes that destroy
> the work irreversibly.
>
> **The three ideas that organize this document:**
> 1. **⚠️ GRAIN is the master concept in both textiles and wood** (§8 → `making-garment-drafting-seams-and-construction`, §16). **Fabric
>    behaves differently along the warp, the weft and the bias; wood moves across the
>    grain and not along it. Both wreck the work when ignored.**
> 2. **⚠️ Wood MOVES, seasonally and forever** (§16). **Every joinery decision in §17 is
>    downstream of that one fact, and cross-grain construction is the single most common
>    reason furniture self-destructs.**
> 3. **⚠️ Laundering has four interchangeable levers** (§22 → `making-laundering-stain-removal-care-and-mending`). **Temperature, chemistry,
>    mechanical action and time trade off against each other — which is why cold washing
>    works if you adjust the others, and fails if you don't.**

---

## §16. ⚠️ Wood Movement

> **⚠️ THE single most important fact in woodworking, and the reason most amateur
> furniture eventually splits itself apart.**
> ⚠️ **Wood absorbs and releases moisture with ambient humidity, FOREVER — a hundred-year-old
> table still moves seasonally.** **⚠️ It moves substantially ACROSS the grain and
> essentially not at all ALONG it.**
> **⚠️ Tangential movement (roughly along the growth rings) is about TWICE the radial
> movement, which is why flatsawn boards cup and quartersawn boards stay flat.**
> **⚠️ A wide solid panel can move by a quarter of an inch or more across its width between
> summer and winter.**
> **⚠️ THEREFORE: never fix a solid wood panel rigidly on all four sides across its grain.**
> **It will either split itself or tear out its fastenings.**

```
⚠️ THE SOLUTIONS, all of which are the same idea
  FRAME AND PANEL  ⚠️ the panel FLOATS in a groove. The oldest and best
     solution to the problem, and why every traditional door looks like that
  BREADBOARD ENDS  attached with elongated holes or a single fixed pin
  ⚠️ TABLETOP FASTENERS  buttons, Z-clips or figure-8s that let the top
     slide relative to the base
  ELONGATED SCREW HOLES  wherever cross-grain fastening is unavoidable
  ⚠️ PLYWOOD / MDF  dimensionally stable — which is the real reason
     sheet goods dominate casework
```
**⚠️ Moisture content**: ⚠️ **acclimatize lumber to the space it will live in BEFORE
building** — **kiln-dried to roughly 6–8% for heated interiors, higher for outdoors.**
**A moisture meter is cheap and prevents expensive failures.**
**⚠️ Reading a board**: **grain direction for planing (⚠️ plane "downhill" or you tear
out), cup, bow, twist, crook; ⚠️ and reaction wood, which moves unpredictably and should
be rejected.**

---

## §17. Joinery

```
⚠️ MECHANICAL STRENGTH COMES FROM LONG-GRAIN TO LONG-GRAIN GLUE SURFACE.
   ⚠️ End grain glues poorly — it's like gluing a bundle of straws end-on.
   Every good joint exists to create long-grain contact and/or
   mechanical interlock
⚠️ MORTISE AND TENON  the frame joint. Strong, resists racking
⚠️ DOVETAIL   ⚠️ mechanically interlocking in one direction — resists
   being pulled apart even without glue. Drawers
⚠️ HALF-LAP · BRIDLE · BOX/FINGER JOINT
DOWEL · BISCUIT · ⚠️ DOMINO (loose tenon)
POCKET SCREW  ⚠️ fast, adequate, and visibly not fine work
BUTT JOINT + fastener  ⚠️ weakest; end grain
⚠️ HOUSING/DADO and RABBET  for casework and shelving
```
**⚠️ The design question is always which forces the joint must resist**: ⚠️ **racking
(frames), tension (drawer fronts), shear (shelves), or compression (legs)** — **and
choosing a joint that resists the wrong force is how a chair loosens.**
**⚠️ Chairs are the hardest furniture** because ⚠️ **every joint is loaded in racking by a
moving person, with long lever arms and no panel to stiffen the structure.**

---

## §18. Adhesives and Fasteners

```
⚠️ PVA (yellow/white)  the default. ⚠️ Stronger than the wood itself in
   long grain. Not gap-filling; needs clamping pressure. Type II/III
   for water resistance
⚠️ HIDE GLUE  ⚠️ REVERSIBLE with heat and moisture — which is why
   antiques can be repaired and modern glued furniture often can't.
   Liquid or hot hide; the conservator's choice
POLYURETHANE  ⚠️ foams (the expansion is NOT gap-filling STRENGTH),
   moisture-cured, messy
EPOXY  ⚠️ genuinely gap-filling, waterproof, good for end grain and
   dissimilar materials
CA  fast, brittle, for small repairs
```
**⚠️ Clamping**: ⚠️ **pressure, not squeeze-out, is the objective; even distribution
matters more than force; and ⚠️ a joint that needs heavy clamping to close is a joint
that's cut wrong and will be under permanent stress.**
**Fasteners**: **pilot holes (⚠️ always, in hardwood), pocket screws, knockdown fittings,
and ⚠️ the fact that screws into end grain hold poorly.**

---

## §19. Wood Finishing

```
⚠️ FILM FINISHES  sit ON the wood — protective, repairable-by-recoating
  ⚠️ SHELLAC   fast, non-toxic when cured, ⚠️ dissolved by alcohol,
     excellent as a barrier/sealer coat under almost anything
  LACQUER      fast, sprayed, ⚠️ solvent-heavy
  ⚠️ VARNISH / POLYURETHANE  durable, slow, ⚠️ hard to repair invisibly
  WATER-BASED  low odour, ⚠️ raises the grain (sand between coats)
⚠️ PENETRATING  soak IN — easy to apply and repair, less protective
  ⚠️ OIL (tung, linseed)  ⚠️ "Danish oil" and "teak oil" are marketing
     names, not defined products — read the actual contents
  WAX  ⚠️ a maintenance coat, not a finish on its own
```
> **⚠️ GOTCHA — oily rags from linseed or tung oil can SPONTANEOUSLY COMBUST.** ⚠️ **The
> oil cures by exothermic oxidation, and a crumpled rag insulates the heat.** **⚠️ Spread
> rags flat to dry, or submerge them in water in a sealed metal container.** **This starts
> real fires every year and it is the one genuine safety hazard in this section.**

**⚠️ Surface prep is most of the result**: ⚠️ **sand progressively without skipping grits,
remove all dust, and ⚠️ raise the grain deliberately with a damp cloth before the first
water-based coat.** **⚠️ Blotch-prone woods (pine, cherry, maple) need a conditioner or a
shellac washcoat before stain.**

---

## §20. Upholstery

**⚠️ The traditional stack, bottom to top**: **frame → webbing → springs (⚠️ coil, tied
eight ways, or sinuous/zigzag) → burlap → edge roll → stuffing → muslin → wadding →
top cover.**
**⚠️ Foam**: **density vs firmness are DIFFERENT properties** — ⚠️ **density predicts
LONGEVITY, firmness predicts feel, and cheap furniture uses low-density foam that feels
fine and collapses within a couple of years.**
**⚠️ Fabric selection for upholstery**: **abrasion resistance measured in double rubs
(⚠️ Wyzenbeek or Martindale — different tests, not interconvertible), cleaning codes
(⚠️ W water-based, S solvent, WS either, X vacuum only), and ⚠️ railroading (running the
fabric sideways to avoid seams on wide pieces).**
**⚠️ Reupholstery is worth it when the FRAME is good** — **hardwood, joined rather than
stapled** — **and rarely otherwise.**

---

## §21. Seating and Frames

**⚠️ Ergonomic basics**: **seat height ~16–18", depth ~18–22", ⚠️ seat angle and back angle
(a reclined seat needs a reclined back or you slide out), lumbar support, and armrest
height.**
**⚠️ Structural**: ⚠️ **triangulation and stretchers resist racking; corner blocks stiffen
frames; and the failure mode of nearly every chair is the joint between leg and rail
working loose under repeated racking** (§17).
**⚠️ Wobble diagnosis**: ⚠️ **a wobbling chair is usually a loose joint, not a short leg —
and gluing a loose joint without first cleaning out the old glue produces a repair that
fails again within months.**

---

# PART IV — CARE