{"id":7971,"date":"2026-10-15T04:25:09","date_gmt":"2026-10-15T04:25:09","guid":{"rendered":"https:\/\/chinametalfoundry.com\/?p=7971"},"modified":"2026-10-15T04:25:09","modified_gmt":"2026-10-15T04:25:09","slug":"casting-packaging","status":"publish","type":"post","link":"https:\/\/chinametalfoundry.com\/fr\/blog\/casting-packaging\/","title":{"rendered":"Casting Packaging: Export Crating, Rust Prevention and Freight Damage Control"},"content":{"rendered":"
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A container of castings can survive five weeks at sea and still fail the moment the crate is opened \u2014 rust blooms on a machined bore, a crushed bottom crate, a missing IPPC stamp that holds the shipment at customs. Casting packaging<\/strong> is the last process step nobody writes into the drawing, and the first one the buyer blames when parts land unusable.<\/p>\n<\/div>\n

This guide treats casting packaging as an engineering and cost problem, not a packing-list afterthought. It covers the four-layer protection system, how much water actually condenses inside a 40 ft container on a tropical route, what ISPM-15<\/a> means for your crates, how to size desiccant, and when an upgraded packaging spec pays for itself \u2014 with two cost models you can copy into your own RFQ. Standards and practice notes referenced from AFS<\/a> et ASTM<\/a>.<\/p>\n

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Export crating is a load-bearing structure, not a box: the bottom crate in a three-high stack carries the two above it.<\/figcaption><\/figure>\n

Why Casting Packaging Belongs in the Cost Model, Not the Packing List<\/h2>\n

Packaging typically runs 1.5\u20133% of landed part value<\/strong> for machined castings and 3\u20136% for heavy iron parts, because a crate heavy enough to survive stacking costs more than the corrosion protection inside it. That number looks small next to tooling or casting cost per piece<\/a>, which is why it gets delegated to whoever is loading the truck.<\/p>\n

The damage it prevents does not look small. A 1.8% arrival-defect rate on a 24,000-piece annual program is 432 parts that either get reworked, get scrapped, or trigger a customer complaint and an 8D report. Weighted at roughly $150 of real cost per incident part \u2014 rework labour, replacement value, freight both ways, and internal quality handling \u2014 that is about $65,000 a year<\/strong> decided by a $10-per-crate decision.<\/p>\n

There is also a schedule dimension. Packaging failures are discovered at goods-in, weeks after the parts were made, so a replacement has to restart the whole chain \u2014 which is exactly the delay pattern mapped out in our casting lead time<\/a> breakdown. A crate that costs $10 more is cheap insurance against a five-week loop.<\/p>\n

If you are new to the process side, start with our Guide sur la fonderie des m\u00e9taux<\/a> and then come back to this page \u2014 every casting packaging decision below depends on how the part was made, what alloy it is, and what condition its surface is in when it reaches the packing bench.<\/p>\n

The Four Layers of a Casting Packaging System<\/h2>\n

Every export-ready casting packaging build is four independent systems stacked on each other. Failures happen when one layer is asked to do another layer’s job \u2014 for example expecting a desiccant sachet to compensate for a crate that lets rain in.<\/p>\n\n\n\n\n\n\n\n\n
Layer<\/th>\nWhat it does<\/th>\nTypical materials<\/th>\n<\/tr>\n<\/thead>\n
1. Surface protection<\/td>\nStops corrosion on bare or machined metal<\/td>\nRust-preventive oil, VCI paper or VCI film, primer or topcoat<\/td>\n<\/tr>\n
2. Moisture control<\/td>\nKeeps the micro-climate dry for the whole voyage<\/td>\nDesiccant (CaCl\u2082 or clay), PE liner, sealed bag<\/td>\n<\/tr>\n
3. Cushioning and separation<\/td>\nStops part-to-part contact damage in transit<\/td>\nEPE foam sheet, corrugated dividers, edge protectors, dunnage<\/td>\n<\/tr>\n
4. Containment and unitisation<\/td>\nCarries stacking load, survives handling, moves as one unit<\/td>\nPlywood crate, pallet, steel or PET strapping, stretch film<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Layers 1 and 2 are chemistry; layers 3 and 4 are mechanics. Most buyer specifications get layer 4 right \u2014 everyone argues about crate thickness \u2014 and leave layers 1 and 2 to the supplier’s default, which is where corrosion claims come from. A good casting packaging spec states all four layers explicitly, because the supplier’s default is built for the cheapest route that usually works.<\/p>\n

Layer 1 is not always a packing decision. If the part is primed, painted or otherwise treated before it reaches the packer, that treatment is the real first layer \u2014 see how surface treatment<\/a> et traitement thermique<\/a> change what the packer is protecting. Writing a casting packaging clause without knowing the surface state is guesswork.<\/p>\n

Rust Prevention: Oil, VCI, Desiccant or Coating<\/h2>\n

Pick the casting packaging protection method from the surface condition and the voyage length, not from habit. As-cast surfaces with intact mill scale or paint tolerate a lot; a machined bore at Ra 1.6 \u00b5m will flash-rust in a humid afternoon.<\/p>\n\n\n\n\n\n\n\n\n\n
Method<\/th>\nTypical salt-spray resistance (ASTM B117)<\/th>\nBest used for<\/th>\n<\/tr>\n<\/thead>\n
No protection (as-cast, dry store)<\/td>\n4\u20138 h before first rust spots<\/td>\nDomestic or short inland moves only<\/td>\n<\/tr>\n
Thin rust-preventive oil film<\/td>\n24\u201372 h<\/td>\nMachined faces on short sea legs; cheap, but needs degreasing at goods-in<\/td>\n<\/tr>\n
VCI paper or VCI bag, sealed<\/td>\n200\u2013400 h equivalent protection in a closed pack<\/td>\nDefault for machined castings on 30\u201345 day ocean routes<\/td>\n<\/tr>\n
Primer or topcoat (epoxy, polyurethane)<\/td>\n500\u20131,000 h<\/td>\nAs-cast parts stored outdoors at destination; see casting surface finishing<\/a><\/td>\n<\/tr>\n
VCI + desiccant + PE liner (combined)<\/td>\nVoyage-rated, not hour-rated<\/td>\nHigh-value machined parts, tropical routes, long dwell at port<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

How much water actually condenses inside a 40 ft container<\/h3>\n
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“Container rain” is not a myth, and it is easy to size. Take a 40 ft high-cube container with 76 m\u00b3 of internal volume loaded on a humid day:<\/p>\n