Uneven CED coating of Stainless Steel
A discussion started in 2002 and continuing through 2017 . . .(2002)
Q. Our coating parts are made of stainless steel with not complex shape. After CED coating some area have uneven film, it can see clearly that film thickness is so different. I have checked and have adjusted spray force of rinsing but no improvement. I would like to know why it occur and how to do. Another question how can I improve film adhesion of this substrate.
Thank you forward to your kind response.John Stroker
A. Frankly, it is difficult to answer without being able to examine the problem. None the less, lets try. What do you mean my uneven - is the DFT very different. Have you verified that using a good DFT measuring instrument? Or do you have orange peel? Or does the film have a texture?
It is difficult to have variable film thickness especially to the extent that is is visible to naked eye. CED normally works +/- 2 microns.
Orange peel could be because of improper coating power supply. Check the output from the rectifier.
A texture - pig skin effect could come from incorrect P/B value.
Hope this points you in the correct direction!
Mohali, Punjab, India
March 24, 2017
Q. I have a problemwith result of our EDP:
The ED Coat is uneven spots nearest to Anolyte membrane.
- Bogor, West Java Indonesia