Macro Etching, a How to Guide
It never fails, every time we do a macro etch in a video, we get the question, "how do you do that"? So, in this episode, we explain it step by step. It is a pretty simple process really.
The first thing you will need is a weld sample. Cut the sample where you want to view the cross section of the weld and polish up the area. This is the most time consuming part of the process as you need to get a good polish on it. It doesn't have to be perfect but the higher the polish, the better the sample will turn out. There are several methods to do this so whatever option works best for you will work.I usually start out with an 80 grit, then 120 grit, following that with a 220 grit, this will get out all the deep scratches. After that, you can start using the red polishing pads and follow that up with a blue one. That typically will get you to a good spot. You can also use a cotton wheel with some polishing compound which will get you a high mirror finish. Once the piece is polished, put a few drops of 5% Nital or 10% Ferric Chloride on the weld area. These items can be ordered from your local weld supply store and one bottle will probably last a lifetime. You can also use Naval Jelly which is available at any of the big box stores. Naval jelly does an ok job but its not the greatest and it takes much longer to develop the weld nugget. Regardless of which chemical you choose to use, make sure you are wearing the proper safety gear for that chemical. I recommend reviewing the SDS (Safety Data Sheet) to see what the manufacturer recommends for PPE. There you have it, thats the process I have used for years to do macro etching on weld samples. I hope you found this article informative and wish you success on your future macro etches. Until next time Make Every Weld Better Than Your Last!
About Jason Becker
Jason Becker is a welder/fabricator with 22 years of field experience in the welding industry and a Marine Corps Veteran. He is also an AWS Certified Welding Inspector and Certified Welding Educator (CWI/CWE). While teaching welding at his local college, Jason pursued his Bachelors Degree in Construction Management from Seminole State College and graduated with honors in 2016. He now works full-time as the co-host for Weld.com.