Question about AR lower finishes

[alamo5000]

I bought a brand new lower from CMT and the inside of it was not fully finished with whatever coating they use. Because of the location of it cosmetically I am not worried about it, but I am wondering if there are any other 'possible' things I should worry about such as corrosion or whatever? If so I will need to contact them.

The rest if the finish looks good. Functionally I don't think I should be concerned about it but I am throwing this out there just in case and for 2nd opinions.

7893

[Jerry R]

Just my $0.02, but corrosion shouldn't be a problem with an aluminum receiver. Birchwood Casey makes an Aluminum Black that will "stain" the unfinished portion. I would use that, if it were me. You could send it back, and they will make it right, but you're out of the usage while the fix is being done. Hope this helps.

[alamo5000]

Just my $0.02, but corrosion shouldn't be a problem with an aluminum receiver. Birchwood Casey makes an Aluminum Black that will "stain" the unfinished portion. I would use that, if it were me. You could send it back, and they will make it right, but you're out of the usage while the fix is being done. Hope this helps.

If it won't corrode then it's in a place that will be inside of the gun. Everything else appears good.

This is probably my 10th order (or more) from them. I will email them just to see what they say.

Not super concerned other than it's a $250 lower. These things happen. Once the gun is together though you cannot see it even if you separate the upper and lower.

I don't know jack squat about metals though so I want to make sure corrosion won't be an issue.

[Uffdaphil]

If it were mine I’d do what jerry said. Dab in the aluminum black, let dry and repeat until dark enough. It works great on engraved SBR lettering.

[UWone77]

You should send them a photo and have them replace it. You paid a premium price and you should expect it to be perfect.

[alamo5000]

You should send them a photo and have them replace it. You paid a premium price and you should expect it to be perfect.

Yes. This. For the price I should get a premium product. I already emailed them with a photo. We will see what they say.

[SINNER]

Trapped air when submerged in the anodizing tank. That location and inside the bolt catch pocket are 2 common areas. No implications other than appearance. These days I'm not sure I'd consider CMT's pricing as premium for a billet lower. Premium for forged these days, maybe.

[BoilerUp]

Seems like that counts as a cosmetic blemish that should not be sold at full retail.

[SINNER]

I guess after paying more for forged Knight's and LMT's with a much worse finish than I've ever seen from CMT I'm more realistic about incidental finish imperfections than most.

[alamo5000]

Seems like that counts as a cosmetic blemish that should not be sold at full retail.

This is the crux of the issue. I paid full retail for it. I am sure it will work just fine but it should have been put in the scratch and dent sale bin.

[UWone77]

Trapped air when submerged in the anodizing tank. That location and inside the bolt catch pocket are 2 common areas. No implications other than appearance. These days I'm not sure I'd consider CMT's pricing as premium for a billet lower. Premium for forged these days, maybe.

Personally, I'd just use it, but you and I aren't most people, you have dozens of lowers and a few hundred dollars is a minor purchase to you. This isn't the norm though. I don't blame people for wanting a first quality lower when they pay retail for one.

[Joelski]

I guess after paying more for forged Knight's and LMT's with a much worse finish than I've ever seen from CMT I'm more realistic about incidental finish imperfections than most.I hear ya there. My KAC lower looked like Chuck Norris borrowed it for target practice and he wiped out the Taliban during his lunch break. Although not a fan of fake MOJO, I am a fan of MOJO, even it got picked up in the plush KAC storage dumpster.. errr vault before somebody decided it was cheaper to sell them than melt them down.. and I'mgood with that. [:D]

But yeah, if it bugs you, the price should buy you the right to be satisfied with your purchase, regardless of where, or how much. That's consumerism.

[alamo5000]

I heard back from CMT. They said they do not consider this as a blemish because it will be completely covered up and that it will not degrade over time.

They said this happened because of a bubble forming during the dying part of the anodizing process and it will not degrade over time. "The surface is anodized with no concern for corrosion"

Overall I think it will never be seen again and if it won't degrade then whatever.

[Aragorn]

Wait, so even though you paid for it, and there was a definite and irrefutable issue with its finish, they’re not going to refinish it or do… anything for you because they don’t consider it blemished, even though it is, just because of its location?

Man, way to get your company smote from the consideration pile with all the other myriad options available…

[alamo5000]

Wait, so even though you paid for it, and there was a definite and irrefutable issue with its finish, they’re not going to refinish it or do… anything for you because they don’t consider it blemished, even though it is, just because of its location?

Man, way to get your company smote from the consideration pile with all the other myriad options available…

I'm kinda torn. On one hand it will never be seen by anyone unless I change triggers. For all practical intents and purposes it won't matter. This is assuming they are correct regarding there won't be any corrosion which I have no basis to say otherwise.

On the other hand this is not a $79 receiver. That should not be that way. Not at all.

I'm kinda going back and forth. Is it a small issue? Yes. But at the same time it's not cool to sell it at full price when it is flawed.

This is my 4th CMT build and they have been really nice people so I'm reluctant to be an asshole about it, especially since in the end it won't matter and it will be covered up forever.

[UWone77]

Wait, so even though you paid for it, and there was a definite and irrefutable issue with its finish, they’re not going to refinish it or do… anything for you because they don’t consider it blemished, even though it is, just because of its location?

Man, way to get your company smote from the consideration pile with all the other myriad options available…

I'm with you. Jeff is a personal friend of mine, so obviously I know he has good intentions, but if I'm paying $250+ for a lower, a consumer should expect to the lower to be perfect.

[alamo5000]

I'm with you. Jeff is a personal friend of mine, so obviously I know he has good intentions, but if I'm paying $250+ for a lower, a consumer should expect to the lower to be perfect.

If you want to please put in a word about it.

It should be obvious that I really like CMT. The basic principle behind getting a premium receiver set is that it should not have things like this.

[mustangfreek]

But....

Your never gonna se it..

Alumahyde it or forget about it and shoot some suppressed rds thru it and cover it in junk..lol

[SINNER]

I'm so glad I don't deal with the public. LMAO.

[biljiczop]

If it were mine I’d do what jerry said. Dab in the aluminum black, let dry and repeat until dark enough. It works great on engraved SBR lettering. techzpod.com (https://techzpod.com/) mobdro apk (https://get-mobdrovip.com)

[Joelski]

I guess after paying more for forged Knight's and LMT's with a much worse finish than I've ever seen from CMT I'm more realistic about incidental finish imperfections than most.

Right? Remember that thread on M4C where the guy complained about the blush on the anodizing? He got told those receivers are for guns that kill bad guys, so either kill some BG's or go back to waxing the vag. Not an issue. A little CLP and those cleaned right up.

[alamo5000]

If it were mine I’d do what jerry said. Dab in the aluminum black, let dry and repeat until dark enough. It works great on engraved SBR lettering.

I didn't even do that. I just used it. It's covered up by the trigger anyway. It will stay covered as well.

I went back and forth at first, but CMT said that it will not corrode so I just put it together and went with it.

If it was visible it would be a completely different story.

[Former11B]

Unless you get a CMC type trigger, it’s not going to be completely covered up but I’m nitpicking that aspect of it

Just because it’s not on the outside portion of the receiver doesn’t mean it’s not in a FUNCTIONAL part of the receiver. There’s no way you could resell that as an unblemished lower no matter what they say.

I’d have to cover that up with something like Aluma-Black.