News

We publish what we learn about black cathodic electrodeposition, answer the questions customers ask most, and post company news. Explaining the process clearly is the first step in earning trust.

COMPANY NEWS

Company news

2024-10

Relocated to Dalang, Dongguan: Xintai Metal Surface Treatment is established

In 2024, to meet growing demand, Dongguan Xintai Coating Technology Co., Ltd. moved its entire operation to Dalang Town, Dongguan, and established Dongguan Xintai Metal Surface Treatment Co., Ltd. The new plant sits in Guangda Manufacturing · Dalang Tech Park, with 3,200 m² of floor space and quick access to the Guan-Shen and Chang-Hu expressways. All existing business, engineering staff and customer relationships transferred to the new entity.

Company newsCapacity upgrade

2025-11

Line upgrade complete: four e-coat lines plus imported inspection equipment

The line upgrade is finished: two automatic and two manual e-coat lines, four in total. The automatic lines run high-volume production; the manual lines handle low-volume, high-mix work, unusual geometries and prototype runs. We also brought in a Konica Minolta spectrophotometer (Japan), a ZGM gloss meter (Switzerland) and a Fischer coating thickness gauge (Germany), so thickness, color and gloss are measured rather than judged by eye.

Equipment investmentQuality control

TECHNICAL ARTICLES

Technical articles

These are the technical questions that come up most often in our plant and from customers. We have written them up for reference.

2026-08

Four parameters that control e-coat film thickness uniformity

Uniform film thickness is the main reason to choose e-coating over spraying, but uniformity does not happen by itself. It depends on holding four parameters steady: voltage (sets the deposition rate), bath temperature (affects film resistance and how much deposits), solids content (affects throwing power and film build), and dwell time (directly sets how much deposits). Rack design and anode placement change the field distribution too, and therefore where the coating ends up thicker or thinner. Our practice is to fix the parameters per part type and check them on a schedule, rather than let operators adjust by feel.

Thickness controlProcess parameters

2026-07

Why MIM parts get pinholes after e-coating, and how to prevent them

Sintered MIM (metal injection molded) parts contain interconnected micro-porosity. During pretreatment those pores fill with cleaning liquid; in the oven the liquid vaporizes, expands and pushes pinholes through the film. There are three ways to deal with it: (1) add ultrasonic cleaning to pretreatment so liquid is displaced out of the pores; (2) apply a suitable sealing treatment to reduce open porosity; (3) drain and blow off thoroughly before baking, and use a stepped ramp so residual liquid escapes slowly. In production we usually need all three together, which is exactly why MIM parts have to be validated during sampling.

MIM partsDefect analysis

2026-06

E-coat vs black oxide vs paint: choosing a black finish

The difference between the three processes fits in one sentence: choose e-coat for corrosion resistance, black oxide for low cost, paint for a simple cosmetic finish. Black oxide is only 1–2 μm thick and is essentially an oxide layer with limited corrosion resistance, usually topped up with oil. Paint goes on thicker but misses recesses, varies in thickness and sags, and wastes roughly 50% of the material. E-coat at 15–25 μm is deposited by an electric field, so it reaches edges and cavities, uses over 90% of the coating, and performs far better in salt spray. For complex precision hardware that needs a consistent appearance and genuine corrosion protection, e-coating is usually the better choice.

Process selectionComparison

2026-05

How 1,000 hours of salt spray is actually achieved: three factors

Salt spray resistance is not a matter of spraying the coating thicker. Three things decide it: pretreatment first — the density and uniformity of the phosphate layer set the bond between coating and substrate. This is the step most often overlooked and the one that matters most; coating formulation second — a high-corrosion e-coat shields the substrate far better than a standard formulation; and cure third — too little temperature or time leaves the film under-crosslinked and less dense, and salt spray results drop off sharply. Let any one of the three slip and the numbers fall. That is why we insist on process control with batch records instead of a single outgoing inspection.

Salt sprayQuality control

FAQ

About this section

Do the figures in these articles apply to every part?

Not exactly. They are experience values taken under standard process conditions and on common substrates. Real results depend on substrate type, pretreatment method, coating formulation, part geometry and the requirements on the drawing. Treat sample-run measurements as the reference — we provide a full inspection report once sampling is done.

Can these articles be republished?

Yes, with attribution to Dongguan Xintai Metal Surface Treatment Co., Ltd. and a link to the original. For commercial use or technical questions, contact us by phone or email.

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