Coating thickness
A great many surfaces are a thin layer over something else entirely. Once you know how thin, most compatibility questions answer themselves.
In detail
The single most useful thing a reader can know about a surface is often not what it is made of but how much of it there is. Vehicle clear coat is on the order of forty to fifty microns. Decorative plating is measured in microns too. An anodic layer on aluminium is finite and cannot be regrown domestically. A laminate worktop's decorative layer is a printed paper. A mirror's reflective coating and backing are exposed at every cut edge. Once a surface is understood as a finite layer, three rules follow without needing to be memorised separately. Abrasion spends it rather than marking it, so every polish, cream and pad is a withdrawal from an account that cannot be topped up — the conservation position on plated silver is exactly this, that plate carries a finite thickness and frequency should therefore be minimised. Chemical attack on a coating is not recoverable by cleaning, because there is nothing beneath it of the same material. And a coating usually fails at its edges and its stress points first, which is why damage appears at a mirror's rim, a laminate's seam, a moulded plastic corner and a wheel's rim rather than in the middle of a panel.
Why
- Tarnish is explained by Coating thickness
- Silicone residue is explained by Coating thickness
- Bird droppings is explained by Coating thickness
- Brake dust is explained by Coating thickness
- Vehicle clear coat is explained by Coating thickness
- Lacquered metal is explained by Coating thickness
- Silver plate is explained by Coating thickness
- Plated and coated tap finishes is explained by Coating thickness
- Mirrored glass is explained by Coating thickness
- Anodised aluminium is explained by Coating thickness
- Laminate worktop is explained by Coating thickness
- Furniture polish is explained by Coating thickness
- Leather conditioner is explained by Coating thickness
- Conditioning is explained by Coating thickness
- Gold plate and vermeil is explained by Coating thickness
Sources for this page
Sources
Caring for your collections: Silver and plate
The Institute of Conservation (Icon) · Trade or professional body
Relied on for: That polishing removes metal, that plate carries a finite thickness of silver over a base metal, and that polishing frequency should therefore be minimised. (states this directly)
Verification: a person has read the passage relied on.
Read on — The tarnish, cleaning, and methods-to-avoid sections. Supports the claim as stated.
AAMA 609 & 610-02: Cleaning and Maintenance Guide for Architecturally Finished Aluminum
American Architectural Manufacturers Association (AAMA), 2002 · Standards body
Relied on for: That marks resulting from mistreatment of anodised aluminium may be permanent. (states this directly)
Verification: a person has read the passage relied on.
Read on — Read in full. Sections 3 General, 4.1 light surface soil, 4.3 organic coatings, and 5 Cleaning Precautions. Supports the claim as stated.
Glass Technical Paper FB06-05: Proper Procedures for Cleaning Flat Glass Mirrors
National Glass Association (NGA), Mirror Division, 2019 · Trade or professional body
Relied on for: That a mirror carries a reflective coating and a backing exposed at the edges which acidic and alkaline cleaners attack. (states this directly)
Verification: a person has read the passage relied on.
Read on — 'Care and Cleaning of Mirrors', the numbered recommendations 1 to 8. Supports the claim as stated.
Last reviewed by a person on .