Zinc Plating

You might want to start with your pre-cleaning process, like contaminants in the wash and rinse solutions. Also check the human factor too.

6-7% rework on how much production?

Definitely sounds like poorly pre-cleaned parts. Should get the appropriate testing equipment to analyze the wash and rinse solutions to see what the changes are over time.

Start with new solutions, record and check on a regular basis(timing would depend on how much use each solution gets), and create a data base of your findings based on the surface area plated between each test. After all, the cost of plating is based on surface area which gives you total plating material cost and dwell time. This will eventually give you timing for solution replacement or purification.

It would also be very useful for QA to have a DFT gauge to ensure you are meeting the specifications required.

Preparation, preparation, preparation!

Yupp and all of the above!

Sounds much like poor preparation of the parts, blistering is normally caused by a contaminated surface and dullness due to a very thin coating. Measure the coating thickness of the dull components against the good components.

I am sure you have a thickness tester as a standard quality control measure.

How can you ever be so sure!?

You are right. I must have taken a momentary fit.

I don't know what the competition is like where you are at, Gajera. Where I am, we have only one Zinc Plater. They do good work, we've never had an issue with their work. The next closest one, I'd have to go to someone that is five hours away. I am assuming that you probably don't have any competitors very close to you either. What I suggest is that you go visit another Zinc Plating shop, one that is not close to you, so you don't pose a threat in stealing customers, and see what processes they do. Find out what their rework percentage is. If theirs is lower than yours, then maybe you can benchmark your processes after theirs.

You might want to check your Standard Operating Procedures, make sure everyone is following them. If you don't have Standard Operating Procedures, start creating them. Standard Operation Procedures gives you something to measure from in supervising people and making sure they are performing their duties correctly and makes it easier to keep people from cutting corners.

Pick the brains of those, who work for you, see if they have any ideas for making improvements and implement some of their ideas. That will give them the feeling that you take their ideas seriously and will work harder to continue coming up with things that can improve operations and they will be more accepting to new procedures because they feel they are part of the decision making process.

Anytime there are mistakes made that cause rework, document it and keep it in a folder along with any solution that was applied to prevent the mistake from happening again so you and anyone else can review. If you don't document things and keep record of the problems and solutions and note the success of any solutions, then you will be making the same mistakes again and again.