Spares Rolling Around the Locker? Print Labelled Storage Jars Sized to Fit

Every boat has the same drawer: loose screws, spare fuses, split pins, cable ties, a few mystery washers and the one fitting you need right now, somewhere underneath. In a seaway it gets worse, because everything migrates, rattles and ends up in the bilge. A set of labelled, screw-top jars fixes most of it, and you can print them to exactly the size of your locker.

Why store-bought jars rarely fit a boat

Kitchen jars are made for kitchen shelves. On a boat, lockers are odd-shaped, shelves have fiddles at fixed heights, and you want the jar to be as wide as the space allows without wasting height. Plastic tubs from the supermarket also crack with UV and age, and their printed labels rub off. A printed jar can be sized to the gap, and its label is embossed into the body, so it never peels or fades.

The protagonist: a free parametric storage jar

The Storage Jar with Screw Lid + Custom Name is a wide-mouth jar with a screw-on lid that has a knurled grip. According to the product page, you set the diameter and height, type your label text, and the lid and lettering adapt automatically. You download a ZIP containing the jar and the lid. It is free and for personal use.

What to measure

• Locker opening and depth: the jar must clear the opening with your hand around it.
• Shelf height: leave a few millimetres above the lid so you can lift it out.
• What goes inside: a fuse assortment needs a small jar, a box of washers a taller one. A wide mouth lets you get fingers or tweezers in.
• Label: keep it short. Three or four words embossed around the body read better than a sentence.

Material and print settings

The product recommends PETG, PLA or ASA, at 0.2 mm layer height with 3 perimeters, and the lid prints best open-side down. My practical take for boat use:

• PETG for general stowage below deck. It tolerates humidity and a hot cabin better than PLA.
• ASA if the jar lives in a cockpit locker or anywhere that gets sun. See our UV resistance guide.
• PLA only for dry, cool lockers; it softens in a closed cabin on a hot day.

Print the jar and lid with the same settings and check the thread fit before you fill it. If the lid is tight or loose, tune your printer first; our tolerance calibration guide covers it. Threads are not watertight: a printed jar keeps things together, not dry. For moisture-sensitive items such as spare fuses and electrical connectors, add a sachet of silica gel or use a gasket (see sealing 3D prints).

Making a system out of it

One jar helps; a standard set transforms a locker. Some ideas:

• Print all jars the same diameter and vary only the height, so they stack and share a footprint.
• Label by job, not by object: "Engine spares", "12V fuses", "Rig pins".
• Use a colour per zone: one for engine, one for rigging, one for electrics.
• Put the heavy jars low and wedge the locker with a foam strip so nothing slides.

Related designs

If your storage is on a wall rather than in a drawer, the Modular Jar Kit mounts one to three square jars on a rail, and we cover the idea in this wall rack guide. For cans, bottles, pens and cups, the Modular Cylinder Holder Kit uses the same wall-bar approach. Browse everything in Interior & Cabin, or the free designs.

A note on food

The jar is designed as a general storage container. Printed surfaces have tiny layer gaps that can trap residue and bacteria, so do not assume a printed jar is food-safe for tea, coffee or anything you will eat unless you have verified the material and finish. Our food-safe printing guide explains the limits. For spares and hardware, there is no such concern. To build the full kit, see the onboard spares kit.

Safety note

Printed parts are not certified marine equipment. Verify the material and suitability before use, and do not rely on a printed container for anything critical, such as flares, medical supplies or safety gear that must stay dry and reliable. Inspect your jars regularly, since UV, heat and age affect plastic.

Questions about sizing or printing? Email us at info@marinelab3d.com.