That said, it wouldn't surprise me one bit if you got a slide that wasn't treated. Or if the quit treating them and just didn't pass on the info. Nothing would surprise me at this point.
While Glock has, at a number of different points in the past, quietly made changes to the design (with the occasional disastrous result from inadequate or nonexistent testing
, as you described), I still think that deliberately skipping the Tenifer treatment would be far too major of a change to be made in secret. Maybe I'm wrong in this regard and will be proven so in the near future, but for now it's easier to believe that a few guns are going to be defective.
The tenifer treatment is illegal in the US and most of the rest of the world. Very nasty stuff. But it lends a quality to the metal that is simply awesome.
"Tenifer" is merely one of several trade names for ferritic nitrocarburizing. There are a number of different but related processes that could all interchangeably be called "Tenifer" or "Melonite" for example. Read about it here at the source:
http://www.durferrit.com/en/unternehmen/firmengeschichte.htm
Perhaps they've changed the process with negative results, I don't know, but it would still be called Tenifer because that's what Glock calls it (just a name).
Oh yes they do--hand me one of your non-defective Glocks and I guarantee you that I can make it rust in no time.
Normally they wouldn't, though.
and although I haven't tried it, I'd bet trying to cut one with a file would be difficult at best until, and if, you got throught the treated surface.
Again, hand me a Glock and I can remove the Tenifer from it easily--just give me some coarse sandpaper and a few minutes.
It isn't thick, but it is 70 (something hardness scale) and supposedly as hard as a file.
It's harder than a typical file, but then again diamond is harder than all of these materials, and if you hand me a diamond and a soft metal hammer, I can still smash it into a million bits.
So I guess the point here is to avoid handing me anything.
No, the actual point is that there is no such thing as absolutely impervious, indestructible materials (especially when they're defective to begin with).
The black stuff you see is now a paint, kind of shiny, but the old ones had the tenifer treated surface turned flat black, kind of like parkerizing (I don't pretend to be a metal expert, I am only parroting what I have heard and read).
The finish on top has definitely varied over time. It's pretty tough, too, as finishes go, but it does wear a lot faster than the Tenifer underneath.
I'd call Glock, a couple of times in case you get more than one story, and get to the bottom of it. In my experience, they shouldn't do this. The Glock even holds up well against salt water.
Agreed, although if saltwater gets to the springs and other parts inside, you could get rust on those fairly quickly.
That is why I kind of think you got one that missed getting treated maybe?
That or something went wrong with the treatment. Either way, I think that Glock should replace the slide (with a properly-treated one, I hope!).
Give it a good wipe down with oil, wipe it as dry as possible, then shine a cool white LED light on it. That shade of light is great for spotting rust.
Interesting, I would have expected that a light source that has more orange and red spectral content would be better for spotting rust.
Cool white LEDs typically have very little of those colors (unless they have an extremely high color rendering index, which is exceedingly rare). Perhaps incandescent lights and "warm" white LEDs have too
much orange and red for this purpose, which can hurt contrast, and perhaps "neutral" white LEDs would be the best of all because in my experience they do help distinguish between certain colors better (particularly between green and brown on the ground, for example).
Glock's new finish is no where near as resistant to corrosion as their old finish, and quite honestly I don't think they're using Tenifer case hardening anymore, it looks like Melonite. People will say the two are the same thing but they're not, Tenifer is much better and easier to do correctly.
Like I said earlier, there are a number of different but related processes, any of which could be called "Tenifer" or "Melonite"--this is in accordance with what the company that developed them says, as referenced above. They are simply trade names. Apparently some folks have assigned these names to two specific processes, but the reality is that they're just names.
As for which two processes these are, I'm not sure what people have in mind. Usually when I see "Melonite" mentioned it is in reference to a process or set of processes that is/are used on certain stainless steels, as had been done on XDs and still on S&W M&Ps, for example. In that case, unless Glock has switched to using stainless steel, which I seriously doubt, I don't know why they'd use a process designed for stainless steel, but that's what people are effectively saying (perhaps without realizing it).
By the way, when the XD, which had been plagued by rust issues early on, was switched to chromoly slides (or plain stainless as an option), a different process was used--one that was probably very similar or identical to the process used on the chromoly slides of Glocks--for case hardening and corrosion resistance, but they still called it "Melonite" anyway (just a name). The "Melonite" process used on the M&P's stainless slide is different despite having the same name, and when done properly it does not appear to affect the corrosion resistance of the stainless steel. Sometimes defective ones reached the market, however, and it looks like the same is true all around, even for Glocks.
And what did you mean by "it looks like Melonite"? The finish that you see on the outside is not Tenifer/Melonite, it's something different altogether.
Glocks are made of steel, and steel can and will rust. In this case, considering all of the evidence we have so far, it appears that the Tenifer treatment on this particular Glock's slide is defective because it should normally resist corrosion better than the slide stop, which does not have the same treatment yet remains rust-free in the OP's case (acidic/salty skin notwithstanding). Obviously something is wrong--that happens, too, despite Glock's well-deserved reputation for quality and consistency. It's still a mass-produced product that for cost reasons is subjected to very limited testing at the factory--in all such cases it is up to the consumer to find the defects and report them to the manufacturer in order to get them fixed.