Bronze and brass have unmistakeable natural patinas, which provide a perfect foil for strong and dramatic planting, such as evergreen specimen trees.
Both materials are also some of the longest lasting of planter materials, particularly bronze.
IOTA’s planters are manufactured from 1.2mm bronze / brass sheet clad onto 2.0mm or 3.0mm stainless steel. The resulting double-skin planters deliver the unique aesthetic of both, whilst relying on the superior strength and stiffness of steel for the planters’ technical performance.
IOTA’s bronze and brass planters are made from architectural-grade sheet, clad onto robust stainless steel planters.
The inner stainless steel planters are fully-welded and faired, and fabricated to the highest standards. Although these planters will not be seen, their structural integrity is central to the longevity of the final bronze / brass-clad planters.
The architectural-grade sheet is bonded to the inner stainless steel planters using industrial contact adhesives. These adhesives not only create an extremely robust and long-lasting bond, but their flexibility is also necessary to mitigate the differential thermal expansion rates of the bronze/brass and stainless steel.
All of the edges and corners of the bronze or brass sheet are then welded and faired, before the finished planters are expertly patinated by hand.
Bronze and brass planters are highly comparable, with differences being at the margin. The most commonly specified material for planters is brass; and, in fact, most of the windows and storefronts visible across London that are called "architectural bronze" are actually an alloy structurally closer to high-tensile brass [copper and zinc with a trace of manganese or lead].
Material, Performance and Technical Considerations
Feature | Bronze Sheet Planters | Brass Sheet Planters | |
| Material | Primary Alloy | Traditionally an alloy of 88% copper and 12% tin. Adding additional elements can add superior strength and corrosion resistance. | An alloy primarily made of copper and zinc. Varying the ratios creates different levels of strength and workability. |
| Raw Color | Deep reddish-brown. | Bright yellow-gold. | |
| Aged Patina | Darkens into a rich, deep statuary brown or dark charcoal-green patina, rather than a bright green. | Oxidises over time into a muted, antique brown before eventually developing a pale, powdery green verdigris. | |
| Performance | Rigidity | Highly rigid; resists flexing under soil weight. | More malleable; requires thicker gauges for larger planters. |
| Corrosion Resistance | Exceptionally high [marine-grade]. | High, but prone to zinc stripping if exposed to harsh salts. | |
| Longevity | Virtually indefinite. When exposed to rain and soil, bronze forms a tough, self-protecting patina layer [copper carbonate] which seals the underlying metal from further degradation. | 30 to 50 years for thin sheets, but 100+ years for heavy architectural gauges. While brass also forms a protective patina, it is more vulnerable to harsh chemical environments. | |
| Cost | More expensive. | Less expensive. | |
| Technical Considerations | Structural Degredation Risk | None. Bronze does not warp or degrade from frost, UV rays, or extreme heat. The Only Risk: Acidic fertilizers or heavily pooled water can eventually cause pitting. However this process takes place over many decades; and with IOTA's construction methodology, this risk is mitigated, as the bronze is not in contact with the growing medium. | Dezincification. If unlined brass stays in constant contact with wet, acidic soil or chemical fertilizers, the zinc can slowly leach out of the alloy. This leaves behind a brittle, porous copper frame that can eventually crack under the pressure of expanding roots or heavy soil. With IOTA's construction methodology, this risk is mitigated, as the brass is not in contact with the growing medium. |
| Manufacturing Complexity | Requires specialist high-heat brazing or TIG welding. | Readily soldered or brazed with standard workshop tools. |
Bronze and brass planters are typically specified for high-end, public-facing, and structurally demanding environments where premium aesthetics must align with generational longevity. Rather than just being planters, they are treated as permanent architectural fixtures.
Such environments include:
Speak to IOTA about the potential benefits of Bronze and Brass for your specific project.
