Burnished brass · For architects
The figures that belong in a tender document, and the cases in which we advise against burnished brass.
Examples from completed projects, a selection from considerably more.
Whether burnished brass suits another area of use is something we settle project by project. Please ask before you specify it.
Material data to EN 1652 and the manufacturers' material data sheets, weight per square metre calculated with a density of 8.44 kg per cubic decimetre for CuZn37.
The decision belongs in the specification. It does not determine how the surface looks on handover day, but how it looks in ten years.
The metal stays open and keeps reacting with its surroundings. Outdoors the surface darkens and develops its own marking over time. That is not a defect, it is the property of this finish.
Suitable when the change is part of the design.
A wax layer slows the exchange with the air. The development continues, but more slowly, and marks from handling are easier to remove. Wax wears off and has to be renewed.
Suitable when the surface is indoors and someone can take on the care.
The lacquer closes the surface. The colour stays at the state of the day the surface left the workshop. The texture of the substrate remains visible, the reaction underneath stands still. The price for that is finality.
Suitable when the surface should look unchanged for years or is heavily used.
The most common damage is done with the best intentions. A cleaner takes the dark surface for tarnished brass and polishes it bright. Ten minutes undo what the workshop built up. Whoever cleans the building should know before the first clean.
Galvanic corrosion. Brass is nobler than aluminium, zinc and galvanised steel. In direct contact with moisture present, the less noble metal is attacked. Solution: a substructure and fixings in stainless steel, or separating, non-conductive layers.
Every surface is unique. Temperature, concentration, processing time and handwork lead to fine differences. The colour character is repeatable, the exact marking is not. For large continuous areas we agree in advance how elements are produced and sorted.
The finish belongs in the specification. Natural, waxed or lacquered decides how the surface looks in ten years. Leaving that line open may produce a surface that behaves differently from the one that was designed.
For architects and planners who specify burnished brass or carry it into detailed design. The specification text goes straight into the bill of quantities, the data sheet provides the figures for substructure, structural checks and tender comparison. Both PDFs are available here directly, no registration.
