Ecoat – also known as electrocoat or electrophoretic paint – is a liquid immersion coating process that utilizes a chemical resin-water emulsion and electricity to build a protective coating layer on conductive metal substrates. E-coat is well known for it’s use in automotive applications but it also has a history of use on variety of non-automotive products

1. Metal parts are loaded onto coating racks that hold and fixture the parts as they move through the process line. These parts travel though a pretreatment series of tanks that clean, etch and apply a conversion coating preparing the surface for the E-coat step.
2. During the E-coat coating process metal parts are submerged in a liquid coating bath that is an emulsified mixture of coating resins and water. Solvents and acids make up another small fraction of the bath that keeps the emulsion/mixture balanced. Pigments and matting agents in the emulsion provide the color and surface texture of the finished coating.
3. Once submersed, electricity is applied in a controlled manner to initiate the coating process and film build. The electrical charge alters the pH of the solution at the surface of metal making it bond while the combination of voltage and time determines how thick the coating layer builds on the part surface.
4. After the coating bath they travel through a number of rinse baths prior to final curing in an oven where the paint cross links to fully cure to a hard, durable finish.

There are three types of ecoat - epoxy, acrylic and polyurethane ecoat. We have epoxy and polyurethane ecoat on our line. Epoxy ecoat is the industry standard, gloss black in color with no UV stabilizers. It is often referred to as underbody or primer because it lacks UV stability. Polyurethane ecoat is UV stable and can be colored – we have matte black and matte grey on our line. Both ecoat varieties have excellent chemical resistance. Both ecoat varieties run 15-25 microns in thickness. The epoxy is a softer coating than the polyurethane making it more forgiving to dings although both are very physically durable.

Raditional epoxy ecoat is a great product but it lacks UV stabilizers to stand up to prolonged outdoor UV exposed applications. After prolonged exposure an epoxy ecoat will bleach or chalk as the sunlight oxidizes the coating. Unlike epoxy, our polyurethane ecoat from LVH Clearclad contains UV stabilizers that provide excellent UV durability. The UV stabilizers are a major selling point for polyurethane and allow for ecoat as a standalone, final finish. Current and past UV sensitive polyurethane applications have been architectural lighting, automotive sensors, head lights, firearms, drones and electronics.

Ecoat is very thin and performs best around 15-25 microns of thickness (.0005”-.0009”). An average powder coat thickness is 2-3 mils thick (.002”-.003”). Often times customers seek out ecoat because the powder coating is too thick or uneven by comparison causing mating or other tolerance issues on a part. If your part has tighter tolerance requirements you should consider how ecoat may solve the problem.

Customers are often surprised at how well ecoat transfers heat between parts or to the environment. The typical approach to heat transfer is to mask areas down to the substrate but that can be difficult, expensive, and tedious. Past customers have been able to use thermal paste right on top of the ecoat between mating parts. Outside testing has shown our matte black ecoat has an emissivity rating of about .96 making it a great way to release heat from your device as-is. Customers have replaced plating solutions with our matte black ecoat and witnessed significant improvements in emissivity. 

Durability is usually the second most important characteristic of a coating after aesthetics. Unfortunately durability means something different in every application and it depends on what you need. A general rule of thumb is the greater the coating thickness the more protection you get from corrosion or physical damage like scratches and dings. The hardness of a coating may play an important role too where a softer coating resists dings better but a harder coating resists abrasion better – it all depends on the application. Both epoxy and polyurethane ecoat are very durable for a coating that is roughly one third the thickness of the average powder coating. Epoxy is softer and provides great wear resistance but it lacks UV stabilizers for final finish applications. The polyurethane is harder and more vulnerable to dings but it contains UV stabilizers for use in the sun.

Ultimately Ecoat is a topical coating on the metal substrate and not part of the substrate itself like anodize or to some degree plating. Ecoat can be scratched off much like a paint compared to anodize and plating. In firearms applications it’s tough to beat a hard anodized surface for its durability and that is why it’s a great option especially on billet metals. That said many die cast customers prefer ecoat’s ability to coat the surface uniformly and show less of the substrate (relative to thickness) and it’s alloying effect that may yield uneven or splotchy anodizing or plating. Moreover environmental regulations have made various plating operations scarce or hard to reliably source. The thickness of ecoat and benefits like improved emissivity might be other advantages over plated finishes. While Ecoat might not eclipse hard anodize it has many advantages that make it a worthy competitor to anything less.

Typically ecoat comes in the color that is already installed on a production line. The maintenance and operation of an ecoat bath are very involved compared to opening a color bag of powder coating. A custom ecoat color is possible in polyurethane but the project would require substantial annual volume to maintain a bath – 100k EAU or more. We have space on our line to facilitate custom colors for large OEM customers with the right project. Otherwise our polyurethane distributor, Clearclad Coatings of Harvey IL, is a resource for customers seeking custom ecoat capability.