Stainless Steel, High-Grade Material for Metal Garden Objects
Steel sorts under the name of “stainless steel“ show a high corrosion resistance. The reason is the protective film, developed by the chemical compounding, which is called “passive layer”. Non-oxidizing steel has a unique ability, it is self-healing. On the basis of its alloy content it develops an extremely thin, transparent passive layer on the surface. Even if the non-corroding steel is being scratched or damaged, it instantly develops this passive layer under the influence of oxygen in the air or in the water again. That is why stainless steel does not need any coating or other forms of surface protection.
Bench substructure, made from stainless steel, seat rest made from black plastic
“Stainless steel” does not always equal “stainless steel”. For outdoor purposes and in nearly all cases Gartenmetall® uses the especially high-graded and corrosion resistant stainless steel with material number 1.4404 (V4A).
Compared to the common stainless steel (V2A) this stainless steel has got an increased resistance towards chloride, acids and sulphur dioxide. We categorically advise against using chloride-containing water admixtures e.g. for reducing water turbidity, as it can – if used intensively – lead to extra strain and corrosion of the material.
In principle Gartenmetall® can deliver all surfaces. Well-known surfaces are brushed or grinded. The daily use, however, has shown that “rotex-grinded” surfaces are especially suitable for metal garden objects. Because of the undirected polish the sunlight is broken evenly and fingerprints are hardly invisible. And the most important advantage: Scratches, that are caused by installation or use, can be removed easily and without loss of quality on site.
Rotex-grinded Gartenmetall®-stainless steel
Attention: Handling of stainless steel
Stainless steel (V2A and V4A) can oxidize at the surface because of adhering external iron particles. These particles can come to the surface e.g. by touching the steel, by rust particles from nearby patina surfaces or by abrasive cutting. If the rust particles have not been on the stainless steel surface for very long, they can normally be removed with a simple kitchen sponge. But if the particles have already rusted into the surface, then we recommend the use of special steel cleaners as we offer them.
Maintenance cleaning with surfaces made from stainless steel
Abrasive powder should not be used, as it scratches the surface. Very oily and greasy stains can be removed by using alcoholic cleaners and solvents, e.g. spirit, isopropanol or acetone, that are uncritical with stainless steel. Splashes of mortar and cement can be removed with warm, undiluted phosphoric acid. Please rinse afterwards with neutral, ideally demineralized water. Alternatively vinegar can be used, diluted with water, depending on the level of dirt.
As additional care for stainless steel surfaces we recommend the same polish as for chrome-plated parts.
STAINLESS-STEEL-CARE for maintenance cleaning
Cleaning with persistent stains
A remarkably strong stainless steel cleaner is our Gartenmetall® product STAINLESS-STEEL-LOTION. It was especially developed and is especially produced for removing corrosion stains on stainless steel. At the same time the surface is being cleaned, optically brightened and maintained with a seal. However, it should not be used for the “normal” maintenance cleaning of stainless steel as the surface is processed sharply.
STAINLESS-STEEL-LOTION for removing corrosion stains on stainless steel
Visible rust stains on stainless steel before the treatment
After the treatment the rust stains are gone.
Suggestion for Tender Template
“High-quality stainless steel, material number 1.4404, AlSI 316L (V4A) or of equal value, material properties according to DIN EN 10088 – 2. Surface of visible sides rotex-grinded up to sample. All welds stained and passivated.”
reference (in extracts):
Merkblatt 965 – Reinigung und Pflege von Edelstahl-Rostfrei im Bauwesen (Informationsstelle Edelstahl Rostfrei, 2009)