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Overlanding: 7 Dry Bag Mistakes to Avoid

What overlanding does to a bag that a weekend trip does not

Overlanding combines three stresses that rarely occur together: continuous vibration across a wide frequency range, sustained abrasive dust, and full-spectrum UV at altitude. A bag that has been perfect for twenty weekends can fail on a single 600 km gravel stage, because the failure modes are cumulative and largely invisible until they are not. The three are also mutually reinforcing: UV weakens the film, dust abrades the weakened film, and vibration propagates the resulting crack.

Distance matters too. On a weekend you can repack, inspect and improvise. On a ten-day route with two water crossings and no resupply, an unnoticed failure on day two costs you sleep for eight nights. That is why the overlanding approach is redundancy, inspection and repair, in that order, rather than simply buying the heaviest bag available.

Mistake 1: treating waterproof as dust-proof

The ingress protection code has two digits, and the second one is the one everybody quotes. IPX7 means the enclosure survived immersion to one metre for 30 minutes; the X means it was never tested against solids at all. The IEC defines the code in IEC 60529, and the solids digit runs from IP1X to IP6X, with IP6X meaning fully dust-tight under a defined test. A bag can be genuinely IPX7 and still deliver a camera full of grit.

Overlanding dust is the worst case: mineral particles from 2 to 60 microns, generated by the vehicle itself and following it in a low-pressure wake for hundreds of metres. Fine dust behaves less like sand and more like a gas. It finds the gap in a zip slider, the stitch line in a webbing tab and any fold that has not been pressed flat, and it stays there, abrading on every subsequent vibration cycle.

The fix is a roll-top closure plus an inner liner for anything sensitive. A roll has no slider and no teeth, so there is no pumping mechanism, and three folds pressed flat give a genuinely good particulate seal. Cameras, medication and documents then go inside a second sealed pouch, because two independent barriers are worth more in dust country than any single rating.

Mistake 2: filling the bag past the fold line

Roll-top bags lose usable volume to the roll itself, and the amount is larger than people assume. Three folds on a 20 L bag consume 2.5 to 4 litres, which is up to 20 per cent of the nominal capacity. A bag filled to the brim with 20 litres of kit cannot complete even one fold, and a closure that cannot complete three folds is a splash cover rather than a seal.

The habit that fixes it is a fixed fill line and an air press. Pack to roughly 85 per cent of nominal volume, press down on the contents to expel the air before the first fold, then roll. Trapped air is not neutral on a vehicle: it makes the bag prone to bursting at altitude, it pushes against the fold from inside, and on a corrugated road it acts like a spring that slowly works the closure open.

Altitude compounds this. A bag closed at sea level and driven to 3,000 m sees an internal overpressure of roughly 35 kPa, which is enough to deform a soft bag noticeably and to stress a weld line that was already under strap load. Purge valves exist for exactly this reason, and if your bag has one, use it after packing rather than after rolling.

Mistake 3: one giant bag for the whole trip

A 90 L bag looks efficient on paper and fails in the field. It is the first thing you load and the last thing you reach, it weighs 25 kg when full, which is beyond what most people can lift safely from a roof rack, and it puts every category of kit behind a single closure. If that closure is damaged by a strap or a sharp edge, you lose sleeping bag, clothing and food together.

Three bags with fixed jobs is the standard overlanding answer, and the split is by consequence rather than by size. One bag for sleep, one for clothing, one for food and cooking, each between 30 and 60 litres, plus a small grab bag in the cab. A 40 kg load then becomes four lifts of 10 kg, and a single failure costs you a category, not the trip.

Access is the hidden benefit. On a ten-day route you will open the food bag three times a day and the clothing bag twice, and you will almost never open the sleep bag. Packing in that order means the sleep bag can be buried deep, sealed once and ignored, while the food bag rides at the tailgate where it belongs.

Mistake 4: leaving bags on the rack through the UV day

A roof rack is the worst place on the vehicle for soft goods and the most convenient place for bulky kit, and that tension is resolved badly more often than not. A dark bag on a rack in 32 °C air reaches 65 to 70 °C on its surface within an hour, and UV dose accumulates: at 2,000 m elevation, irradiance is roughly 8 to 10 per cent higher per 1,000 m than at sea level, so an alpine overlanding route delivers a tropical dose with cold air.

PVC ages fastest under that combination, because heat drives plasticiser migration and UV drives chain scission, and the two together produce the chalky, stiffened bag that splits at the fold. TPU laminate has no plasticiser to lose and holds flexibility far longer, which is the main reason expedition operators specify it. Lighter colourways help regardless of film: a tan or grey shell runs 12 to 15 °C cooler than black.

The practical compromise is to accept roof duty for heat-tolerant kit only and to cover everything else. Empty water containers, recovery boards and dry firewood are fine on the rack. Clothing, food and bedding go inside, or on the rack inside a light-coloured cover with an air gap, which drops surface temperature by 15 to 20 °C for about 400 grams of extra kit.

Mistake 5: crushing the closure with a ratchet strap

A ratchet strap generates far more tension than a soft bag is designed to take. Two clicks past snug on a 25 mm strap easily produces 150 to 250 kgf, and that load is delivered across a 25 mm line rather than across a broad face. The result is a crushed fold, a deformed buckle, and in the worst cases a peel failure at the weld near the closure.

Vibration makes it worse, because a strap that is tight on a static load slackens and retightens thousands of times over a corrugated stage, and each cycle works the closure a little further open. The classic symptom is a bag that was sealed at the start of the day and is wet inside at the end, with no visible damage and no water anywhere else.

The correct load path spreads the strap across the bag rather than through it. Two straps over the top of a bag sitting in a cradle or between rigid boxes works well; a single strap pulled down across a soft bag does not. Where a strap must cross a closure, put a 100 mm pad under it, and never route a strap over the folded section itself, which is the part that does the sealing.

Mistake 6: storing fuel, water and food together

Diesel and petrol vapour migrate through polymer films over days, not minutes, and the effect is strongest exactly where overlanding puts it: a hot enclosed space with the fuel can and the food bag in contact for a week. Twenty litres of diesel weighs 16.6 kg and a full steel can weeps at the gasket under vibration, after which everything in the same bag tastes of fuel. Water containers are not innocent either; a plastic cube picks up fuel smell from the air alone.

Separate by chemistry and by position. Fuel goes outside the vehicle or in a sealed exterior locker, never in the cabin and never in a bag that will ever hold food. Water goes in its own containment bag as a second wall, as far from fuel as the vehicle allows. Food goes in a welded bag with a closure that has never been near hydrocarbons, because TPU will hold that smell long after you have washed it.

One more rule from expedition practice: never repurpose a bag. A bag that has carried fuel carries fuel forever, and a bag that has carried detergent or sunscreen should not become a drinking water bag. Mark bags with a permanent marker for their contents and accept that the marker is permanent, because the alternative is a week of coffee that tastes of diesel.

Mistake 7: no repair kit and no inspection

A 5 mm puncture in a TPU bag is a five-minute repair with the right kit and a ruined week without it. Overlanding routes produce punctures from sharp luggage edges, from grit trapped between a bag and a rack bar, and from the simple act of dragging a loaded bag across rock. The repair itself is straightforward: clean, dry, patch, press, wait.

Inspection is the other half, and it takes five minutes a week. Turn each bag inside out in good light and look at the weld corners, where fatigue shows as a white stress line before it becomes a split. Run a thumb along every fold for grit, squeeze the closed bag and listen for a hiss, and check that buckles still hold tension when pulled.

Abrasion is measurable rather than guesswork: the ASTM maintains standard abrasion test methods used across the soft goods industry, and any serious spec sheet should be able to state which method and which load a film was tested at. If a listing cannot tell you that, it is a reason to keep looking rather than a reason to trust the photograph.

Dust exposure by road surface

Dust load varies by an order of magnitude across the surfaces an overlanding route will throw at you, and the exposure is cumulative over the day rather than concentrated in any one section. A convoy of four vehicles is far worse than a solo vehicle, because each one lifts dust for the ones behind, which is why spacing matters as much as speed.

Two habits scale with that table. Wipe the fold line with a damp cloth before every close, which costs ten seconds and removes most of the risk, and never open a bag on the vehicle during a dusty stage. Opening a bag at a fuel stop in a silt cloud admits more dust in five seconds than a hundred kilometres of sealed driving.

A three-bag load plan for a ten-day route

The plan below covers two people for ten days with resupply at day five. It assumes a mid-size four-wheel drive with a roof rack and rear drawer system, and it keeps every bag under 15 kg so that any one of them can be lifted by one person. Total soft-bag volume is 130 litres against roughly 900 litres of usable vehicle space, which leaves room for water, fuel and recovery gear.

Note that the heaviest item by far is water at 21 kg, and it is placed low and chocked, exactly as it would be on a desert route. Everything else is arranged by access frequency, with the sleep bag deepest because it is opened least and the food bag on top because it is opened most. That ordering is the difference between a five-minute camp set-up and a twenty-minute one.

Water crossings and river recovery

A water crossing is the one event that tests a bag in the way the rating describes, and it is also the one event where a bag can cost you the vehicle. Anything strapped outside will be submerged for the duration of the crossing, so it needs three folds and a closure above the load line, and anything inside needs to be above the wading depth of the vehicle, which is usually the bottom of the door sill.

After a crossing, open and check before you drive on. Water enters at the closure under pressure even in a bag that passes a static immersion test, because a crossing adds flow and a bow wave. A 30-second check at the far bank is cheap; discovering a wet sleeping bag on night three of a wet stage is not.

Pre-departure checklist

• Fill every bag to about 85 per cent and confirm three folds complete without force.
• Purge air or open the valve after packing, and again after a big altitude gain.
• Split the load into three bags with fixed jobs, each under 15 kg.
• Keep fuel outside the cabin and never in a bag that will carry food.
• Cap strap tension at hand-tight plus one pull, with pads under every contact.
• Pack a 700 g repair kit and inspect weld corners weekly.
• Wipe every fold line before closing, and never open a bag in a dust cloud.

Expedition operators and rental fleets use the same checklist as a purchasing brief, because volume, film thickness, closure type, colour and hard points are the five lines that decide whether a bag survives a season of this work. Our production partner has built waterproof bags since 2014 in an SGS-verified 4,950 m2 facility, with a 500-piece minimum and sampling in 6 to 10 working days, and overlanding briefs are among the most demanding we take.

Finish by walking the vehicle once with the checklist in hand, because most failures are set up in the first ten minutes of loading rather than on the road. Compare your plan with our ATV durability notes for vibration detail and the motorcycle luggage setup for strapping geometry, then use the multi-day touring plan if the route stretches past ten days. Punctures are covered step by step in the puncture repair guide, and the broader buying checklist is worth a final read before you commit to a size. All of our bags share one closure geometry, which you can see across the full product line.