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ARMORTHANE PROTECTING YOUR WORLD

PROTECTING YOUR WORLD

ARMORTHANE PROTECTING YOUR WORLD

Grain Bin Coatings: Protecting Storage From The Steel Out

    Grain Bin Coatings:
    Protecting Storage
    From the Steel Out

    How spray-applied polyurea coatings help grain operations fight corrosion, moisture, and wear, and the one question to settle before anyone coats the inside of a bin.
    A grain bin looks simple from the outside. Corrugated steel, a cone roof, a foundation ring. But the conditions in and around a bin are hard on materials. Moisture cycles, temperature swings, the constant movement of grain against steel, and the slow chemistry of corrosion all pull against the structure from the day it goes up.

    When a shell starts to fail, the cost is rarely just steel. It shows up as spoiled grain, downtime in the middle of harvest, and eventually a capital replacement nobody budgeted for. A protective coating is one of the more cost-effective ways to slow that clock. Here is a practical look at how spray-applied coatings work on grain storage, where they belong on the structure, and the food-contact question every operator should answer first.
    grain bin

    What actually wears a grain bin out

    Most bin problems trace back to a few predictable failure points.

    Corrosion. Steel, moisture, and oxygen are all it takes. Condensation forms on the underside of the roof and on interior walls as temperatures swing between day and night, and that thin film of water keeps surfaces wet far longer than most people expect. Over enough seasons, that is what thins the steel.

    Moisture intrusion at seams and fasteners. Bolted seams, roof panel laps, and eave lines are the first places water finds a path. Once it gets behind a panel, it sits.

    Abrasion. Grain flowing along sidewalls and across floors, plus sweep augers doing their work, wears surfaces down mechanically over time.

    The base and foundation. Where the steel shell meets the concrete ring, moisture gets trapped and corrosion takes hold quietly, out of sight. <br.
    grain bin out
    spray polyurea instead of paint

    Why spray polyurea
    instead of paint or epoxy

    A conventional paint film is thin and relatively brittle. It protects for a while, then chalks, cracks, and lets moisture back to the steel. Epoxy is harder and chemically tough, but it tends to be rigid, which works against it on a structure that expands and contracts with every hot day and cold night.

    Spray polyurea takes a different approach. It is applied with plural-component equipment and reacts in seconds, building a seamless, monolithic membrane with no joints or laps for water to exploit. It stays flexible, so it moves with the steel through temperature cycling instead of cracking away from it. Applied over properly prepared steel or concrete, it bonds tightly and resists the abrasion that grain handling puts on a surface.

    The specific physical properties, tensile strength, elongation, hardness, and cure times, come straight from the product data sheet for whichever system is specified. Those numbers should always be pulled from the TDS, not estimated.

    Where coatings belong on a grain bin

    Not every surface calls for the same treatment, and not every surface should be coated with the same product.

    • Roof and seams (exterior). Sheds water and seals the panel laps and fasteners where leaks usually start.
    • Exterior walls. A corrosion barrier and weather shell over the steel.
    • Base and foundation transitions. The steel-to-concrete joint where moisture collects and rust hides.
    • Secondary containment and handling areas. Spill and containment surfaces around grain handling equipment.
    • Interior grain-contact surfaces. This is where the important question comes in. Keep reading before you spec anything here.
    coatings belong on a grain bin

    The interior question: grain is food

    The interior question:
    grain is food

    Here is the part that matters most, and the part a lot of quick durability pitches skip over.

    The moment a coating touches stored grain, it becomes a food-contact surface. That means the coating has to be certified for food contact for that specific use, under FDA 21 CFR 175.300 or an equivalent NSF food-contact standard, before it goes on an interior grain-contact wall or floor. General durability, corrosion resistance, and a strong data sheet do not by themselves make a coating safe for direct grain contact.

    So the rule is simple. For interior grain-contact surfaces, confirm the food-contact certification for the exact product first. If a product is not certified for food contact, keep it on exterior and structural surfaces where it does real work without touching the grain. That distinction protects the operation, and it is the honest way to spec the job.
    grain is food
    ArmorThane manufactures

    Getting it right: prep
    and applicatio

    Coating performance lives and dies on surface preparation. Most coating failures are not the coating, they are the prep. Steel needs to be blasted or profiled, clean, dry, and above the dew point before anything is sprayed. Rust, scale, and contamination have to come off, because adhesion is only as good as the surface underneath.

    This is commercial work, not a roller-and-bucket weekend project. Plural-component polyurea is applied with heated, high-pressure equipment by trained applicators who understand the spray window and the substrate. That is the difference between a coating that lasts and one that peels in a season.

    ArmorThane manufactures its own coatings and builds its own spray equipment in-house, trains applicators at headquarters, on site, or remotely, and backs the work with 24/7 technical support. There is no franchise model behind it, just direct manufacturer support before, during, and after the job.

    Frequently asked questions

    Only with a product certified for food contact for that use. Confirm the certification for the specific product before any interior grain-contact surface is coated.

    For a structure that moves and stays damp, generally yes. A seamless, flexible, abrasion-resistant membrane holds up to temperature cycling and grain wear better than a thin paint film. Paint costs less up front, but it is thinner and shorter-lived. 

    Yes, but only after the rust and contamination are removed and the steel is properly prepared. Adhesion depends entirely on that prep. 

    It depends on the product, film thickness, surface prep, and exposure. A properly specified and applied system on well-prepared steel significantly extends the service life of the structure. Ask for the specifics tied to the product data sheet rather than a blanket number. 

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    Talk to ArmorThane

    If you run grain storage or coat it for a living, ArmorThane can help you spec the right system for the surface, from exterior corrosion protection to the food-contact question on the inside.

    Call (417) 831-5090
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