Most tool cases do not wear out, they get filthy and then get thrown. The failure sequence we see on returned samples is almost always the same: grit packs into the zipper track, the slider starts skipping, someone forces it, and the tape splits. Cleaning a case takes ten minutes a month and pushes that failure years out.
Weekly: grit first
Empty the case completely once a week if it lives in a vehicle. Tip it upside down and tap the corners, then run a soft brush along the zipper track and vacuum the crevices where the insert meets the shell. Dust and metal swarf are what grind the foam and the lining, and they are also what makes a zipper feel stiff. Check the die-cut insert while it is out: EVA foam that no longer springs back after you press it has taken a compression set and is no longer holding the tool, which on a precision instrument means it is time to replace it, not time to push harder.
Washing the shell
Use lukewarm water at 30-40 C with a pH-neutral detergent diluted about 1:50, and a soft brush or microfiber cloth. Work in short strokes with the grain of the laminate, and rinse with a clean damp cloth rather than a hose, because driving water into the seam under pressure pushes dirt in with it. Never machine wash and never tumble dry: agitation delaminates the fabric from the shell, and heat above roughly 70 C starts to distort molded EVA. Dry the case open and upside down in shade for 24 hours. A 5-10 g silica gel sachet dropped into the cavity afterwards handles the residual moisture.
For specific marks, isopropyl alcohol on a cloth lifts marker pen and adhesive residue without touching the shell. A melamine foam sponge takes scuffs off a PU leather laminate, but go lightly, because it is a fine abrasive and will dull a gloss finish. Baking soda left in the open case overnight, or an activated charcoal sachet for a few days, deals with the smell that builds up after a wet job. Bleach will disinfect but it also fades dyed fabric trims; if disinfection is what you need, use a quaternary ammonium wipe and rinse after.
Solvents must never touch EVA. Acetone, nail polish remover, paint thinner, MEK, toluene and brake cleaner all attack the surface within seconds and dissolve the adhesive behind the laminate, so wipe any splash off immediately with water and detergent. Steam cleaners and pressure washers are out for the same reason: heat and pressure get behind the fabric. Prolonged direct sunlight is slower but just as damaging, since EVA chalks and yellows under UV and dyed trims fade unevenly, so keep the case out of a window. Our EVA tool case line uses a PU leather laminate partly because it survives this routine.
Zipper, handle and seam checks
Brush the teeth, then run a dry silicone or wax-based lubricant along the track; do not use oil, which collects dust and makes matters worse. Pull the slider through a few times and look at the closed teeth from the side: if they stay spread apart behind the slider, the slider is worn and the tape will split soon. Replacement sliders cost very little against a new case. On the handle, check the bar-tack stitch where the webbing meets the shell and the seam line along the base. Any thread lift, or a gap that catches a fingernail, should be repaired before the next heavy load. The laminates and zipper grades we stock for replacement builds are on the customization page, and the small EVA pencil cases follow the same rules at a size you can rinse in a sink.
A fleet customer in Rotterdam keeps a two-year log of zipper replacements across 400 cases and orders 60 sliders every spring. Their spare insert sets for the 2024 shell are on the packing bench this week, cut at 60 kg/m3 because the first batch compressed out after about eighteen months of daily use.