The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Degreasing Galvanised Sheet

2007

We use galvanised sheet metal that is manually scrubbed with a galvanised iron cleaner and scotch brite pad and then painted with a matte black cellulose paint. The current process is very cumbersome and very labour intensive. I am looking for a way or process to do bulk processing of the sheet metal strips without the need to use manual labour to clean each strip individually.

1. Can this be batch dipped in a degreaser or acid like sulfamic acid the degrease before painting? if a degreaser what do I use?

2. If I use sulfamic ACID what concentration and how long

3. where can I learn more about the process?

Helmut Hertzog
Plating Shop employee - Cape Town, South Africa

---

If I am understanding you correctly I think you need a 7-stage zinc phosphatizing system. In this case the cleaning and chemical prep is done by sequentially immersing the parts into, or spraying the parts with, a cleaner, a zinc phosphatizing solution, and a post treatment process. There would be no manual cleaning.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2007