Precision cleaning solvents
Published

Adhesion on Galvannealed Material

What causes paint adhesion problems on galvanneal material?

Share

Q. We are having paint adhesion problem on galvanneal material. We have a degreasing facility with a seven-tank process. —A.K.

A. Zinc coated steels can be notoriously difficult to achieve good paint adhesion. Some of the problems are related to the mill coatings and oil that are applied to the galvanneal to ensure they do not oxidize. These can be very tenacious, particularly if shipping from overseas and needing the associated extended corrosion resistance.

Additionally, the zinc coating of a simple galvanized can be one of the most difficult of the zinc coated steels to get good paint adhesion. The galvannealed variety essentially takes the hot dip galvanized steel and bakes it, which will form a zinc-iron alloy that significantly improves the paint adhesion while maintaining the material corrosion resistance.

It is unclear what is involved in your seven-tank cleaning system, but time, temperature, cleaner concentration and agitation are the most important factors to control to maximize the potential of your cleaning system. As mentioned, the lubricants applied at some of the mills can be particularly difficult to remove. I would recommend increasing the time, temperature and cleaner concentration in an effort to better remove the contaminants. 

Related Content

  • 3-Stage Versus 5-Stage Washers

    Columnist Rodger Talbert explains the difference between a five-stage washer and a three-stage washer, and how one provides better corrosion protection over the other. 

  • Corrosion Resistance Testing for Powder Coating

    Salt spray can be useful to help compare different pretreatment methods and coatings but it does not tell us much about the corrosion resistance of a part over time in the field. Powder coating expert Rodger Talbert offers insights into how to get a better idea of how to improve a part’s corrosion resistance in the real world.

  • Advantages to Pumped Eductor Agitation

    Not all agitation methods are created equally. Pumped agitation with eductor nozzles can improve process tanks and quickly show a reduction in operating costs while keeping staff safe, following environmental legislation and preventing pollution.

Cleaning questions ask Kyzen
vacuum vapor degreasers
high-performance systems for efficient parts cleaning
Echoflex modular ultrasonic cleaning machines
Precision Cleaning Solvents
Pickelx one step metal prep
Cleaning Technologies Group
find masking products online
Precision cleaning solvents