Memories of a Coating Tech

Having worked in the coating lab for many years when I get together with other coaters there's always some good stories to tell.

Coating failure!

There's the obvious; forgot to put the shutter in, but have you ever forgotten to actually put the parts in? I did a full 3 hour deposition once and when I was done I turned to make room on the flow bench and son of a...! The optics I was supposed to have just coated were still sitting tooled up ready to go in the chamber! I had to stay late without booking the OT to get them coated like I was supposed to.

I once lobbied hard to use a different material for a prototype. I gave every good reason to set up and characterize the material in the chamber and run the tests. I got permission to do so and the results were as I expected and engineering was happy with the results. The day after testing concluded I received the $20K+ single optic to coat for the prototype device. Somewhere in the middle of a long process the new material I had successfully suggested and put into process exploded and spit molten material all over the part. That was not good! The damage to the polished surface was too much to polish out and the part had to be remade. Luckily management was very understanding. But we never used that material again.

Have you ever made a silly mistake? Or a very costly mistake? Let me know. Change the names to protect the innocent or make your tale anonymous if you like.