Fittings in bronze acquire added radiance over the years. They acquire a very special aesthetic appeal in the course of being used that testifies to a credible process of ageing and to something gained through change.
Patina should not be understood as damaging the material. It is rather a sign of credible aging and profiting from change. Bronze is not a material which is not used up, it is just used.
For our fittings, we use a copper-tin alloy with 92 % copper and 8 % tin, which is called CuSn8, or material no. 2.1030. This composition is characterised by high strength and it is very hard. Its resistance to wear makes it suitable for heavily stressed products which are used every day.
The bronze fittings with FSB 7615 and FSB 7625 finishes finish are first polished and then pretreated using a process especially developed by FSB.
Immersion in a bath for metals containing copper imitates the material’s natural aging process. With this pre-aging, we create a typical bronze patina, which is just as good as that produced naturally. The final waxing in the factory, protects it from external influences which would lead to discolouration of untreated surfaces. On request, pre-aging with a dark patination is possible as version 7615.
Antimicrobial action and surface hygiene
Owing to the increasing occurrence or antibiotic-resistant germs, FSB’s bronze takes on a new significance owing to its bactericide effect. Critical studies in the USA and in Great Britain show that bacteria on copper alloy surfaces are 99.9 % killed off after two hours at the latest. This group of bacteria includes the Methicillin-resistant Staphylococcus aureus (MRSA), one of the most virulent and dangerous germs known.
When the prescribed hygienic measures are carried out at the same time, it was confirmed that contamination was prevented by more than 99 %. Owing to this fact this characteristic of the copper alloy used by FSB, called CuSn8 (UNS designation C52100) has been officially taken up by the EPA (Environmental Protection Agency) into US building regulations, US registration number 82012-2.
Additional information on fittings in Bronze
Regularly handled hardware components in Bronze or Brass are self-polishing in dayto- day use. Any parts with which hands do not come into contact acquire a natural patina as a function of environmental conditions and the surroundings into which they have been fitted. This change in colour relative to the condition of the finish when delivered is natural to the material and as such does not constitute grounds for complaint, let alone a defect.
We use wax to – as far as possible – keep the finish in the condition produced at the works. The wax is used to keep polished Brass or, respectively, the bright copper-coloured patina of Bronze in exworks condition as well as to preclude any natural patina formation during storage, delivery and assembly. Our aspiration is for your Brass and Bronze fittings to arrive “ fresh” at your windows and doors and to only develop a patina in the course of use. The wax employed is safe, biodegradable and can be readily removed by wiping – even without the use of cleaners.
Adding a few drops of cooking oil is known to be effective. Naturally varying environmental impacts may lead to slight chromatic fluctuations in the degree of patination between batches that are unavoidable, with the result that any fittings supplied at a later date will differ from those already in use on your doors and windows and on which patina has already begun to form. This state of affairs is natural to the material and environmentally determined and as such does not constitute grounds for complaint, let alone a defect.
