plating, anodizing, & finishing Q&As since 1989
Pretreatment before stoving paint. How?
We are a small manufacturer and have have recently started manufacturing X-ray Units. We would like to use stoving paint for finishing. We would like to know how to prepare the surface as some people say it should be first treated in acid and then alkali and then washed. Some say we can use phosphate and then directly use zinc primer. the material we use are cold rolled and hot rolled mild steel sheetsAnuj Sharma
The enclosures are obviously used only under interior exposure conditions. A 3 stage cleaner coating process (lightweight iron phosphate) will be quite adequate for this application. It is important that the final rinse water should be below 300 microSiemens, preferably 100, to avoid the likelihood of osmotic blistering.
If production throughput does not justify an inline spray tunnel plant, you can use a single cabinet washer system.Roger Bridger
- Croydon, Surrey, UK
You can process the parts with multi-cation zinc phosphating treatments before painting.DR. D. SEN
- Calcutta, INDIA
A three stage Iron Phosphate cleaner/coater process as mentioned above will work just fine. Under low production conditions or with large parts you can even do the coating and cleaning with a pressure washer. What you need can be had from almost any metal finishing chemical company, along with advice on the system.
- Pearland, Texas