Summary for fingerprints on textured powder coat Discussion
fingerprints on textured powder coat are discussed as a finish problem that may not be solvable by cleaning alone. Rob Maday says the silver textured epoxy powder on thin-walled steel tube develops fingerprint-like mottling over time, and that methyl ethyl ketone removes the marks but also seems to dull the finish, while stripping and repainting is the other sure fix. Terry Hickling answers that the issue is common with aluminum powder finishes and suggests the coating may be made with leafing aluminum flake, which rises to the surface during baking and leaves a bright but more fingerprint-prone film. He says perspiration can attack the exposed aluminum, whereas non-leafing flake is trapped in the film and resists fingerprints better, though it gives a duller appearance. The thread points toward a coating-formulation issue rather than a simple surface-cleaning remedy.
2002
RFQ: I need a product to remove finger prints from powder coating. Many
surfaces are perforated so I cannot use a paste of any type.
Kenny R [last name deleted for privacy by Editor]
– Panama City, Florida
Ed. note: This RFQ is outdated, but technical replies are welcome, and readers are encouraged to post their own RFQs. But no public commercial suggestions please ( huh? why?).
Q. We manufacture display elements and one of these elements is a thin walled steel tube which is powder coated using a textured epoxy powder in a silver color. We are seeing fingerprint-like mottling of the surface over time and handling. The only ways that I have been able to remove this is with
methyl ethyl ketone ⇦ on
eBay or
Amazon [affil link]
(which I suspect is removing a layer of the coating and also dulls the finish slightly) or by stripping and re-painting. Is there any other possibility for removing this? Is it possible that something is reacting with the steel (it is not primed but does go through a wash system)?
Rob Maday
exhibits – metal manufacturing – Eagan, Minnesota, USA
2004
A. Dear Rob,
Your problem is quite a common one – Aluminum powder finishes can be made from leafing or non-leafing aluminum flake. The defects you describe suggests your powder is made using leafing aluminum flake. This means that during the baking cycle the Al flake floats to the surface of the applied powder giving a very bright finish. The aluminum on the baked film surface is subject to attack from perspiration excretion of uric acid), and things can become even worse if handled by the gentler sex at certain monthly cycles.
Non leafing results in the powder flake being entrapped in the powder film and thus protected from finger marks but produces a duller aluminum finish.
Terry Hickling
Birmingham, United Kingdom
2004