How to remove mill varnish
We are going to start with our 8” carbon steel flange. Mill varnish typically is a yellow coating that keeps your flanges from rusting, but often it hides imperfections on the flange face that cause it to fail inspection before being sent to fabrication.
We are going to start the cleaning process by taking Cortec 414 degreaser and a score pad and scrubbing off the varnish. The raised face of the flange is the most crucial part that needs to be cleaned. Next, we are going to take our P3-GIT and do a through inspection of the raised face. For a full in-depth tutorial on how to use the P3-GIT I have linked it in the “I” card at the top of this video and in the description.
Now what we have done our inspection we are marking any imperfections that will cause this flange to fail. As you can see this imperfection does not fall in the critical surface area causing this flange to pass inspection, meaning it is ready to be sent to fabrication.
Next we are taking a different carbon steal flange that we will also clean and inspect. For this one we used black paint to simulate the mill varnish. We are using the same Cortec 414 degreaser to clean the raised face and then inspect it with the P3-GIT as well. As you can see this one has a major imperfection in the flange face also causing it to also need to be quarantined before fabrication.
Alright guys, that’s it!