Immediately after painting, dimples in a polka dot pattern appear. The culprit may not be the paint, but rather the rust prevention oil or lubricant left on the steel. I will explain how to identify and address this issue.
Immediately after application, the paint shrinks and dents like water droplets. If it continues only with steel materials from the same lot, the cause may not be the paint. 【First, please look here】 □ The base material is visible at the center of the dent → Oil residue remains □ Common with coil materials and pressed products → Rust prevention oil, pressing oil □ Only appears where wiped → Oil is spread during wiping 【Why does it happen?】 Steel materials arrive coated with rust prevention oil or lubricating oil to prevent rust and scratches. If even a small amount of this oil remains, the paint cannot adhere to the surface, causing it to be repelled only in the areas with oil. Depending on the type of oil, some may be difficult to remove with regular degreasing. 【Countermeasures you can take starting today】 1. Confirm the type of oil being applied with the supplier of the materials. 2. After degreasing, spray water to check if it beads (water repellency). 3. Record the temperature and concentration of the degreasing solution daily. 【Free materials】 The identification and countermeasures for beading are summarized in "Eiwa Kogei_Painting Trouble Introduction_Identification and Countermeasure Guide."
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Subject: Powder coating of steel materials and pressed products / Verification items: Types of rust-proof oil and lubricant, temperature and concentration of degreasing solution, confirmation of water drainage.
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Countermeasures for defects in baked coatings of steel materials, coil materials, and pressed products, focusing on water droplet-shaped dents, as well as quality control personnel and training for newcomers.
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We are not just a "subcontracted painting factory." Established in 1958, our company has a foundation of painting technology and also specializes in chemical treatment, stripping, and cleaning, functioning as the "external surface treatment department" in your organizational chart. Based on our philosophy of "preparation is eight-tenths of the work," we emphasize participation from the "upstream process" before the drawings are finalized. We conduct test painting on a wide range of metals and difficult materials, and we produce the entire process from assembly, packaging, to delivery, thereby reducing your management workload. Additionally, by being able to perform zinc phosphate treatment in-house, we achieve stable painting quality. Furthermore, our micro-heating stripping technology, which does not use chemicals, maintains the electrical state of the "jigs (hangers)" that influence painting quality. Our approach of "pre-treatment determines painting quality" ensures the stability of the paint film during mass production. Rather than simply "applying specified standards," we work backwards to achieve optimal painting specifications and prevent scratches during transportation, sparing no effort in thorough discussions from the outset. This diligent preparation is the shortest path to preventing rework and minimizing total costs. From the development stage, please utilize the expertise of our specialists as part of your production line.
