What Survives The Container: Packing A Welding Machine For Sea Freight

A machine that welds perfectly at run-off can arrive at the customer's door in a state nobody would accept. The distance between those two conditions is not covered by anything in the specification. It is covered by a wooden case, a sheet of film and a bag of desiccant.

Packing is also the part of a purchase that is entirely the supplier's responsibility and almost never written down in the contract, which is a bad combination for a buyer. What follows is what the sea actually does to a machine, and what we now put in the way of it.

A container is not a dry room. In the sun the roof reaches temperatures that would burn a hand; at night the steel cools below the dew point of the air inside, and the moisture that the cargo and the pallets released during the day condenses on the ceiling and drips onto whatever is underneath. The trade calls it container rain, and it is the reason a machine can leave with bright machined faces and arrive with rust blooms on them.

Then there is movement. A machine standing on castors will walk across the container floor for four weeks; guards chafe against the frame; a plug works itself loose; a foot pedal left unsecured arrives at the other end as a loose object that has been hitting the cabinet. None of that is a manufacturing defect. All of it is a claim.

The walls of a case keep rain and dust off. The base carries the weight, and it is the base that is usually got wrong. The machine has to be bolted down through its own feet or base plate, not strapped; the case needs skids underneath so a forklift can get its tines in without levering against the bottom panel; and the whole thing has to be able to be lifted at the centre of gravity rather than where it happens to be convenient.

A closed plywood case and an open frame are two different arguments. The closed case keeps water out and traps moisture in, so it needs desiccant. The open frame breathes and lets the rain in. We use closed cases, and we treat the inside as a sealed volume: the machine goes into a VCI bag, the bag is sealed, and the desiccant is calculated from the enclosed volume rather than grabbed by the handful.

Copper is its own problem. Electrodes, secondary bars and shunt laminations tarnish in damp air, and a tarnished contact face is a resistance problem at commissioning. They are bagged separately with their own protection rather than left on the machine.

There is a detail that decides whether any of this works. The bag and the desiccant are one system, not two precautions: desiccant thrown loose into a plywood case does almost nothing, because the case exchanges air with the container through every joint and the desiccant saturates on the first day. Sealed inside the bag with the machine, it has a small volume to dry and it stays effective for the voyage. When a supplier says the machine is protected, this is the question worth asking.

Marking matters for the same practical reason. Gross weight, centre of gravity and lifting points stencilled on the case, in the language of the people who will actually lift it, cost nothing and prevent the most expensive kind of damage.

Our first container to the Gulf went out on a pallet with a single winding of stretch film and no desiccant, because the machine was oiled and the oil was assumed to be enough. Thirty-four days later the customer sent photographs of rust on the arm faces, a guard that had bent against the frame, and the foot pedal lying loose in the bottom of the case.

The money was not the point; we replaced the parts. The point was that the customer's first physical impression of our quality was a rust spot on a machined surface, and no amount of run-off video repairs that. Since then the packing has been a procedure with photographs, and the photographs travel with the shipping documents so that both sides can see what was put in the case and when.

A closed plywood case on skids with fork pockets; the machine bolted through the base; a sealed VCI bag around it; desiccant sized to the volume; machined faces greased and covered; loose items boxed and bolted to the base rather than dropped in; shock and tilt indicators on the outside of the case, so that damage in transit is a fact rather than an argument.

And a seal. The container is sealed at our door, the seal number goes on the packing list and on the bill of lading, and we photograph the closed doors with the number legible. A damage claim that begins without a seal number and without photographs of the case before loading is a claim that is decided by whoever is more patient.

A buyer can specify all of this, and the ones who do get fewer surprises.

• Case type and base: closed plywood on skids, or open frame, and who pays for it.
• Whether the machine travels assembled or partly dismantled, and whether the case is returnable.
• Moisture protection: VCI and desiccant, stated as a method rather than as a promise.
• Marine insurance, and whose policy it is, because the claim is filed at the destination and not at ours.
• Packing photographs and the seal number, sent with the documents before the vessel sails.

None of this makes the machine weld any better. It decides whether the machine that welded here is the machine that arrives there, which for a buyer is the same thing.

PDKJ continues to provide customized laser welding and resistance welding solutions based on different materials, workpiece structures, welding requirements, and production applications.

• Spot Welding Machines
• Medium Frequency Inverter Seamless Spot Welding Machine

Send us your part drawing or a sample, and our engineers will run a welding feasibility trial on your own material and recommend the equipment configured for your application.

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Email: jay@gd-pw.com

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