Sidetracked by FNC? Yes. Yes I was.
An opportunity came up to have some of my airgun projects professionally finished. Extra space was available in a batch of parts last week. The parts were to be Ferritic Nitrocarburized--a hardening and blacking process that chemically alters the metal surface with additional nitrogen and carbon. FNC is also known as Melonite or Tenifer. The finish is similar to a case hardening. It's done in a molten salt bath at approximately 1000 degrees F that hardens the surface and makes it both highly wear and corrosion resistant.
H&M Metal Processing in Akron ran the job. Their website has a good description of the process.
I sent a couple barrel sleeves for break barrels and my multi-shot breech. The previous cold blue jobs I had applied look good, but will wear through in spots after enough handling and require rework.
But first, I had to undo all the time spent bluing and take the parts back down to bare steel. There was a bit of hesitation. I didn’t exactly know what to expect from the FNC treatment. Would the finish be uniform? Aren’t the parts already good enough? Steeled up my courage and minutes later, the parts were back in the white.
And then they were in a box and out the door.
A day later, the driver showed up and the parts were done. Oily, but done.
The parts are dark black— like a black oxide finish. But now they’re black and around 64 Rockwell on the C scale. It’s unlikely the finish on the barrel sleeves will ever wear again. The treatment sounds ideal for a break barrel air rifle.
I’m thrilled with this process. Aside from a fresh abrasive blast to remove the cold blue, I did zero prep work. This was a very last minute opportunity.
If this comes up again, the barrel sleeve on the Weihrauch 35E will be a likely candidate.
Back to the QB78 re-seal real soon.
