When buyers compare an aluminum casting pots set from different suppliers, the conversation will usually start with the casting method and the wall thickness. Specs are important but they are not the determining factor of how long the pot stays in service. The coating is. A well cast pot with a poorly bonded coating will fail sooner than an average cast pot with a well bonded surface. Knowing what the coating does, and where it fails, helps procurement teams specify the right product for their market.
What the Coating Does
The coating on an aluminum casting pots set has two purposes, and only one of them is related to cooking performance. The first is non-stick release, which determines how easily food can be released from the surface and how much oil the user has to use. The second is more important for safety. The coating is the barrier between the aluminum body and the food. Bare cast aluminum is not designed to come into direct contact with foods, especially when cooking acidic ingredients such as tomatoes, wine or vinegar. If the coating is scratched through to the metal, the pot should be replaced, not because it is no longer non-stick, but because the food contact barrier is broken.
Failure of Coatings
The loss of coating rarely occurs uniformly over the entire surface. It begins at the edges, and at the points where the rivets or the handle mounts, and at the bottom where the utensils scrape. These are the areas where the coating is thinnest, or where there is a concentration of mechanical stress. In commercial kitchens the first thing that wears is the bottom. Metal utensils are used all the time. In home use, the rim is often the first place to chip, since the coating is applied thinner at the edge and the rim is subject to impact when the pot is set down or stacked. When purchasing an aluminum casting pots set, inquire with the supplier about coating thickness at the rim and base, not just the average over the surface.
Things to Look for Before Buying in Bulk
Two practical checks can help to verify coating quality before committing to a bulk order. The first is in layer count. In general a three layer system (primer, mid coat and top coat) will last longer than a single layer spray. Second is surface preparation. A properly blasted or etched aluminum surface gives the coating something to grab onto. Smooth, un-etched surfaces will tend to peel early. Buyers sourcing aluminum casting pots destined for export markets should also verify that the coating is PFOA-free and that the supplier can provide FDA or LFGB documentation. The most reliable step is sample evaluation prior to bulk production. The visual and functional quality of cast cookware is highly dependent upon mold condition and coating control, which a specification sheet cannot reveal.
