QUESTION
You recently mentioned that Lotus Marques is in the process of manufacturing replacement rear radius arms for my Esprit and they would have an electro-plated finish.
I was wondering if powder coating would be as good as electro-plating?
J.G. - Wyalkatchem, Western Australia.
ANSWER
Electro-plating is where metal components (usually steel) are suspended in a large bath filled with an electrolyte (mild acid).
Also suspended in the same bath (but not touching) is the coating material (commonly zinc, chrome etc)
A DC current is then applied across the target component and the coating material.
Tiny particles (molecular level) are then attracted from the coating material and slowly deposited onto the target component.
The coating grows thicker with current and time leaving a a corrosion resistant metal layer on the surface.
The finished radius arms will be zinc coated followed by a secondary passivated coating which leaves the component gold in colour.
This secondary coating provides an additional level of corrosion protection and is a standard finish on most current production vehicles.
Powder coating is a painting technology that uses paint in a dry powder form (that has no solvent).
This is applied using a special electro-static charged paint gun.
Paint particles are drawn to the target component by the electro-static charge.
When the paint is applied to a new part it appears to drift across from the gun in the form of a cloud.
Once the part is fully coated, its then carefully moved into to an oven where the powder paint is baked on at high temperature.
Baking the powder form paint on leaves a tough and durable finish that is abrasive resistant.
However if the powder coated layer is chipped and reveals the metal underneath, it is very difficult to repair.
One very important point to remember - only ever use powder coating on new bright metal components that have been bead-blasted.
The bead-blasting process provides a suitable "keyed or etched surface" for the paint to adhere to.
Never use powder coating on rusty parts even when prepared correctly.
Rusty parts often contain micro-crevasses so the powder will sit on top of the concealed openings.
Eventually moisture gets drawn into these tiny hollows and the corrosion process continues.
As the rust grows and expands, it lifts the paint off the component surface (some times in large flakes).
Powder coating provides a great surface finish but it has no wicking action where "wet paint" is drawn into voids to prevent further corrosion.
Copyright © 2013 Lotus Marques
You recently mentioned that Lotus Marques is in the process of manufacturing replacement rear radius arms for my Esprit and they would have an electro-plated finish.
I was wondering if powder coating would be as good as electro-plating?
J.G. - Wyalkatchem, Western Australia.
ANSWER
Electro-plating is where metal components (usually steel) are suspended in a large bath filled with an electrolyte (mild acid).
Also suspended in the same bath (but not touching) is the coating material (commonly zinc, chrome etc)
A DC current is then applied across the target component and the coating material.
Tiny particles (molecular level) are then attracted from the coating material and slowly deposited onto the target component.
The coating grows thicker with current and time leaving a a corrosion resistant metal layer on the surface.
The finished radius arms will be zinc coated followed by a secondary passivated coating which leaves the component gold in colour.
This secondary coating provides an additional level of corrosion protection and is a standard finish on most current production vehicles.
Powder coating is a painting technology that uses paint in a dry powder form (that has no solvent).
This is applied using a special electro-static charged paint gun.
Paint particles are drawn to the target component by the electro-static charge.
When the paint is applied to a new part it appears to drift across from the gun in the form of a cloud.
Once the part is fully coated, its then carefully moved into to an oven where the powder paint is baked on at high temperature.
Baking the powder form paint on leaves a tough and durable finish that is abrasive resistant.
However if the powder coated layer is chipped and reveals the metal underneath, it is very difficult to repair.
One very important point to remember - only ever use powder coating on new bright metal components that have been bead-blasted.
The bead-blasting process provides a suitable "keyed or etched surface" for the paint to adhere to.
Never use powder coating on rusty parts even when prepared correctly.
Rusty parts often contain micro-crevasses so the powder will sit on top of the concealed openings.
Eventually moisture gets drawn into these tiny hollows and the corrosion process continues.
As the rust grows and expands, it lifts the paint off the component surface (some times in large flakes).
Powder coating provides a great surface finish but it has no wicking action where "wet paint" is drawn into voids to prevent further corrosion.
Copyright © 2013 Lotus Marques