Keeping a forty-year-old knitting machine working

Almost every domestic knitting machine in use was manufactured between the 1960s and the 1990s. They were built well and they last, but nothing about the support system around them has lasted equally: manuals are out of print, parts come from the second-hand market, and the specialists who service them are fewer every year and charge £60–£150 when you find one.

That sounds worse than it is. These are mechanical machines with no electronics in most cases, the failure modes are few and well understood, and the great majority of what goes wrong is dirt, an old sponge bar, or a bent needle. All three are things an owner can deal with. The purpose of this guide is to draw the line between those and the things worth paying somebody for.

No lubrication schedule or service interval appears here. Those are model-specific, the correct product differs between machines, and the wrong oil in the wrong place attracts dirt and makes things worse. Your machine’s manual is the authority, and where it is missing the model-specific user groups are — which is the standing answer in this hobby for almost everything.

Most common fault

Dirt, by a wide margin

The perishable part

The sponge bar

What kills machines

Damp storage

The authority

Your model’s manual and user group

If you take one thing from this guide, take this. The sponge bar is a strip of foam in a metal channel running the length of the needle bed, and it presses the needle butts down so they sit correctly and return properly. Foam perishes. On a machine of this age it will be flat, crumbling or entirely gone, and it is the single commonest cause of a machine that "does not work" — dropped stitches, needles that will not return, and knitting that looks like a tension problem and is not.

• Assume it needs replacing on any machine you buy — Budget £15–£30 for a new one regardless of what the seller says. A machine that has been in a loft for twenty years has a flat bar whether or not it looks like it. This is the first thing to do with a second-hand machine and before concluding anything else is wrong.
• How to tell it has gone — Pull the bar out and look at it. Healthy foam is springy and stands proud of the channel; perished foam is compressed, hard, crumbly or reduced to dust in the bottom of the channel. If needles feel loose in the bed, or if stitches drop apparently at random across the width, look here first.
• Replacement is a strip of foam in a channel — Replacement bars are sold ready-made for common models, and re-sponging an existing bar with the correct foam is a routine job in this hobby rather than an advanced one. The thing to get right is that the foam must be the correct depth for your machine, which is why buying for the model rather than by eye matters.
• It is consumable, not permanent — Expect to replace it periodically for as long as you use the machine. Treating it as a wear item rather than a repair is the correct mental model and stops people concluding the machine is failing.

• Lint and old oil are the enemy together — Yarn sheds constantly, the fibre works down into the needle bed, and it combines with old lubricant into a grey paste that stiffens everything it touches. A machine that has become heavy to push, or that has developed intermittent faults across the bed, is very often simply dirty. This is the first thing to try and it costs nothing.
• Work along the bed, not at it — A soft brush and a lint-free cloth, working the length of the needle bed and the needle channels rather than dabbing at the visible surface. The dirt that matters is under and between the needles where you cannot see it.
• The carriage underside is where the sticking lives — Turn the carriage over and look at the cams and the running surfaces. Fibre and old oil accumulate here and produce exactly the symptom people describe as the carriage "catching" at one point in the row. Clean it before adjusting anything.
• Do not flood it with solvent — Cleaning products that seem obvious can strip lubricant from places that need it, damage plastic parts, or leave residue that attracts more dirt. Follow the manual for your model, and where there is no manual, ask the user group before applying anything wet.
• Clean when you finish, not when it fails — A brush along the bed after each session takes a minute and prevents almost all of the above. This is the single habit that separates machines that stay sweet from machines that get progressively worse.

A needle problem shows up in the fabric before it shows up anywhere else, and it shows up in the same place every row — which is what distinguishes it from a tension problem or a sponge bar problem, both of which are distributed.

• A repeating fault in one column is a needle — A dropped stitch, a pulled loop or a tuck appearing in the same wale row after row means that needle. A fault appearing randomly across the width is the sponge bar or tension. Reading which of the two you have saves an hour.
• Check the latch first, then the hook — Latches must swing freely and close fully; a latch that is stiff, bent or missing will not close over the yarn and drops the stitch every time. Hooks that are bent or splayed catch. Both are visible if you bring the needles forward and look along the bed at eye level, which is the standard inspection.
• Bent needles are replaced, not straightened — Needles are cheap, available for common models, and a straightened needle goes back to being bent. Replacing one is a routine operation and part of ordinary ownership.
• Inspect the whole bed occasionally rather than only when something fails — Bringing every needle forward and looking down the line takes a few minutes and catches the ones that are on their way out. It is the mechanical equivalent of the tension swatch.

• Damp is the thing that ends machines — Lofts, garages and outbuildings kill knitting machines by rusting needles and beds. More machines are lost to twenty years in an unheated space than to any amount of use. If a machine must be stored, store it somewhere heated and dry.
• Clean before storing, always — Lint holds moisture against metal. Putting a machine away dirty is what turns a season off into a corrosion problem.
• Take the sponge bar out for long storage — It will perish anyway, and leaving perished foam compressed in the channel makes the eventual clean-out worse. Removing it costs nothing.
• Keep the accessories with the machine — Clamps, weights, the sponge bar, punchcards, the ribber connection and above all the manual. A machine separated from its accessories loses a large part of its value and capability, and this is exactly why completeness rather than condition sets the second-hand price.
• Cover it, but let it breathe — A cover keeps dust off. Sealed plastic against cold metal produces condensation, which is the thing you were trying to avoid.

• Anything requiring the bed to come apart — Stripping a needle bed is not a first repair. It is recoverable in skilled hands and expensive to get wrong, and the machine is worth much more assembled.
• Carriage internals beyond cleaning the running surfaces — The cams and their timing are the part where a confident amateur does real damage. Clean it, and if it still catches, ask.
• Anything on a punchcard or electronic machine’s pattern mechanism — The pattern mechanism is the most complicated part of any domestic machine and the least forgiving of exploration.
• Any lubrication question at all — Which product, where, and how much are model-specific and this guide gives none of them. The manual is the authority and the user group is the fallback.
• Where to ask — Model-specific user groups are the defining institution of this hobby and are unusually good — the machines were mass-market, the communities formed around individual models, and collectively they hold knowledge that exists nowhere else in writing. Find yours before you need it.