View Full Version : Is this marred anodizing a problem?
SecretAgentMan
02-10-13, 19:46
I was working on a new build today and decided to do a dress-rehearsal for the installation of a Magpul UBR (my Hammerhead tool hasn't arrived yet, so I was just checking fit and function). The UBR was pretty snug on the receiver extension, but nothing outrageous (I didn't have to use a mallet, which the instructions said might be necessary).
After I removed the UBR from the receiver extension (again, it didn't take too much effort--it was just snug), I noticed that some of the anodizing was taken off of the receiver extension, like so:
http://eyes-only.s3.amazonaws.com/extension.jpg
Obviously, this will never be seen once the UBR is installed again. My only question is if this marring of the anodizing is an invitation for rust to begin forming in the RE, and if so, is there a way I can head this off?
polymorpheous
02-10-13, 19:49
Aluminum doesn't rust.
Cagemonkey
02-10-13, 19:49
Aluminum won't rust. Get some Alumablack from Birchwood and Casey and touch it up.
nothing to worry about. curious, what did it hang up on to scratch it like that?
SecretAgentMan
02-10-13, 19:55
Interesting. I just Googled it and had never noticed the distinction between rust and corrosion. Either way, sounds like this isn't a big deal. Thanks.
SecretAgentMan
02-10-13, 19:57
nothing to worry about. curious, what did it hang up on to scratch it like that?
I'm still not sure why it happened. There is nothing protruding into the path of the receiver extension.
Aluminum won't rust. Get some Alumablack from Birchwood and Casey and touch it up.
Why touch it up? It is totally covered up by the stock. Mine is like that, and I don't bother touching it up.
SecretAgentMan
02-10-13, 19:58
Mine is like that...
Awesome. That's all I need to know.
i had the same problem with a ubr i had. the small screws that go in the cheek piece protrude on the inside against the receiver extension. i just backed them off a bit before removing the stock.
i had the same problem with a ubr i had. the small screws that go in the cheek piece protrude on the inside against the receiver extension. i just backed them off a bit before removing the stock.
Lol, apparently you and I read the same direction manual from Magpul....which clearly states what you said above :)
Lol, apparently you and I read the same direction manual from Magpul....which clearly states what you said above :)
Stop right there! No one reads the instructions until AFTER the task. That is how we figure out where the leftover parts go.
That was the hardest one, now the other 1000 dings and scratches you'll put in her won't hurt at all.
:)
Lol, apparently you and I read the same direction manual from Magpul....which clearly states what you said above :)
lol i actually had no idea that was in the manual, i gouged mine up good the fist time i pulled it off before i figured it out.
When UBRs first came out....they thought this issue was so important that they put a separate bright yellow advisory notice in the boxes as shown here.
http://i888.photobucket.com/albums/ac81/trident1982/DSC09529_zps4551f2b1.jpg
New ones don't come with the seperate cheek piece like the old ones, so I guess they figured most people wouldn't ever be screwing around with the cheek piece screws to begin with...no pun intended :D
Interesting. I just Googled it and had never noticed the distinction between rust and corrosion. Either way, sounds like this isn't a big deal. Thanks.
Fun fact, an analog to iron rusting is aluminum thermite. Sort of.
SecretAgentMan
02-10-13, 22:17
Lol, apparently you and I read the same direction manual from Magpul....which clearly states what you said above :)
I just checked the manual again, and can't find anything about this. I also didn't get the green warning card pictured in this thread. In any case, it doesn't look like my UBR's screws are protruding far enough to cause this finish removal, and if Stickman and others don't think it's a big deal, I'm not worried.
Aluminum is self-healing. When scratched, the exposed aluminum reacts with the oxygen in the air to form layer of aluminum oxide to protect it from corroding.
Rust & Corrosion. There are many types of corrosion, rust being only one type. Only iron and steel can rust as it's the iron that forms rust. Red rust is iron oxide. Green rust occurs when iron reacts with chlorides (sea water is a common source of chlorides) in an environment deprived of oxygen.
Aluminum corrodes but as it isn't iron, it does not rust
Aluminum is self-healing. When scratched, the exposed aluminum reacts with the oxygen in the air to form layer of aluminum oxide to protect it from corroding.
Rust & Corrosion. There are many types of corrosion, rust being only one type. Only iron and steel can rust as it's the iron that forms rust. Red rust is iron oxide. Green rust occurs when iron reacts with chlorides (sea water is a common source of chlorides) in an environment deprived of oxygen.
Aluminum corrodes but as it isn't iron, it does not rust
So iron in, say, fresh water, won't rust nor corrode? Or if it does, very very slowly?
Rust is a type of corrosion. If you have rust, you have corrosion.
It's like all rifles are firearms, but not all firearms are rifles.
Rust forms in the presence of moisture and oxygen. Iron will rust in fresh water, especially if the water has a good supply of oxygen in it.
Parkerizing protects steel in two ways- it forms a barrier that blocks oxygen from getting to it and is porous so it will absorb and hold oil to displace moisture
If your stock system requires instructions, an engineering degree, and a midget to install and remove.... that's insanity.
If your stock system requires instructions, an engineering degree, and a midget to install and remove.... that's insanity.
My vltor scar17 stock didn't come with directions.
That little 2 pronged spring that works the button that allows the stock to slide whipped my fat ass. The guy on youtube who installed it in a minute is a damn liar.
If your stock system requires instructions, an engineering degree, and a midget to install and remove.... that's insanity.
Not if it entertains the midget
kantstudien
02-11-13, 12:06
If you planned on being in a maritime environment, then yes that would concern me. Once corrosion starts through a weak spot in the anodize, it will eat through the rest of the aluminum like a cancer.
But unless you are in a saltwater environment I wouldn't worry about it at all. And Type-II anodize actually penetrates into the metal as well as builds up on the surface of the metal. So unless the gouge is deep, it should be a non-issue.
Cagemonkey
02-11-13, 20:13
Why touch it up? It is totally covered up by the stock. Mine is like that, and I don't bother touching it up.Your technically right, but when it comes to some things, I have a tendency to be a little anal.
Hi everyone, first post here, but I've been lurking for a while. This thread finally prompted me to post. I'm looking for some help with my brand new BCM upper.
I finally snagged one off their site and when I pulled it out of the box to put in my BCG I noticed the marred finish....is this just another candidate for Alumablack?
I've been trying to get this upper for a year now, and now that I have it, this stupid little mark is keeping me awake at night...advice is welcome, thanks!
https://s3.amazonaws.com/jmhdsp/upper.JPG
Yeah, just hit it with some Aluma Black. It won't help the rifle shoot any better but what the heck. On my first rifle a goofed and marred the finish in a couple of small spot. Hit them with some Aluma Black and they're gone
SecretAgentMan
02-12-13, 19:18
Aluminum is self-healing. When scratched, the exposed aluminum reacts with the oxygen in the air to form layer of aluminum oxide to protect it from corroding.
Rust & Corrosion. There are many types of corrosion, rust being only one type. Only iron and steel can rust as it's the iron that forms rust. Red rust is iron oxide. Green rust occurs when iron reacts with chlorides (sea water is a common source of chlorides) in an environment deprived of oxygen.
Aluminum corrodes but as it isn't iron, it does not rust
This is fascinating. Thanks for the insight.
SecretAgentMan
02-12-13, 19:22
I did more investigating tonight, and Trident82 is correct: It was the cheek piece screws that scuffed the finish. They didn't look like they were protruding far enough to take off the finish, but apparently they were, because after backing them out a couple of turns, the receiver extension slides in without any resistance whatsoever.
However, the installation manual no longer says anything about backing out the cheek piece screws. It does mention possibly needing a mallet, so I guess Magpul considers a tight installation to be par for the course now, and any associated wear on the finish to be no big deal.
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