A typewriter that has sat in an attic for forty years is almost never broken. It is dirty, its lubricants have polymerised into varnish, and its rubber has hardened. Cleaning done in the right order fixes the first two problems and reveals which of the third you actually have. Cleaning done in the wrong order turns a two-hour job into a two-month one, because you will spend the extra time undoing decal loss, softened rubber feet, and a paint plate that now shows every brush stroke.

What not to use

Three products are responsible for most preventable damage.

• WD-40. It is a water displacer with a light solvent carrier. It does move grime, but it also leaves a thin oil film that attracts dust, and within a month you will have a stickier machine than you started with. Never in the segment.
• General-purpose penetrating oils. Same problem, larger residue. Reserve for genuinely seized fasteners, never for typebars.
• Household 'oil soap' or furniture polish. Silicone content will contaminate any surface you later try to paint, glue, or re-decal.

Two products are safe and available almost anywhere.

• Odorless mineral spirits (Stoddard solvent, white spirit). Cuts hardened grease without touching paint, decals, or period plastics. Evaporates cleanly. This is the primary solvent for the segment and typebars.
• Isopropyl alcohol, 90 percent or higher. For polished metal, glass keys, and type slug faces. Never on paint, decals, or rubber.

Anything more exotic — acetone, brake cleaner, ultrasonic tanks — belongs to advanced restoration and is easy to over-apply.

The sequence

Work from the top down and from dry to wet. Wet solvent runs downhill, and any grime you loosen must have somewhere clean to fall.

Step 1: dry brush and vacuum

Remove the ribbon and set it aside. Cover the platen with a strip of paper. With a soft one-inch paintbrush, sweep from the top of the segment outward, letting dust fall onto the paper. Vacuum through a cloth over the nozzle so nothing small gets pulled into the machine bag. Ten minutes of dry brushing removes eighty percent of what looks like "grease" on a neglected machine.

Step 2: exterior wipe

A slightly damp microfibre cloth on the paint plate, followed by a dry cloth. No solvents yet. If the paint is filthy with nicotine or attic film, a tiny amount of mild dish soap in warm water on the cloth is fine — but avoid running water over the decals, and dry immediately.

Step 3: keys

Cotton swab dipped in isopropyl alcohol, one key at a time. If the keys are glass, this is safe indefinitely. If they are plastic (mostly post-1955 portables), be brief; long alcohol contact will haze some formulations.

Step 4: the segment

The heart of the job. Tilt the machine forward on a folded towel so the segment overhangs the bench edge and any solvent drips onto the towel, not into the mainspring. With a small artist's brush loaded — not soaked — with mineral spirits, work solvent into the segment slots between the typebars. Two brush loads per slot is enough. Immediately depress each typebar three or four times to let the softened grease work loose.

Do not spray. Do not flood. Do not walk away. The whole segment cleaning should take twenty minutes, and every drop of solvent should evaporate before you leave the bench.

Blot escaped solvent with a folded paper towel pressed against the base of the segment. Repeat the brushing pass twice more with fresh solvent; by the third pass, the brush should stay clean.

Step 5: type slug faces

Roll a strip of masking tape sticky-side up around a small block of wood. Press each type slug into the tape to lift decades of caked ink and paper fibre. For stubborn slugs, a stiff-bristled toothbrush and a drop of isopropyl alcohol finishes the job. The difference in printed characters after this step alone is often the largest single visible improvement in the entire restoration.

Step 6: lubrication (almost none)

A typewriter is a dry-running machine at the segment. The only places that want lubricant are the carriage rails, the escapement pivot, and the mainspring hub. One drop of light instrument oil, applied on the tip of a wire, per location. That is the entire budget. Any additional oil migrates into the segment and starts the varnish cycle over again.

Step 7: test and rest

Type the alphabet twice. Type the pangrams that stress every letter. Note which typebars still drag; a second segment pass with fresh solvent almost always frees them. Leave the machine open on the bench overnight so any solvent still in the joints evaporates before the case is closed.

A first cleaning done in this sequence takes an evening, uses under a hundred millilitres of solvent, and returns almost every non-broken machine to writing condition. The temptation to do more — to strip the paint plate, to soak the segment, to oil everything that pivots — is the temptation to make new problems. Resist it, close the case, and write with the machine for a week before you touch it again.