A question on AR 80% lowers...

[bigbob76]

I didn't do very well with a search on this. Do the guys doing 80% receivers anodize the milled away areas? I see that some of them start out anodized and then after milling there are exposed areas and I wondered if that was a problem as far as wear or corrosion.

[savs2k]

I've never had an issue with it. Its cheaper to pay an extra 10 bucks for an annodized 80 then paying 100 to dip one lower. My buddy annodized his after he milled it and had to end up shaving extra off anyways because the coating was too thick. Ended up with a silver pocket anyways

[ENTHUSIAST]

Bob they are aluminum so no issues with oxidation if you dont get the milled portion anodized.

Most of the people that I have talked to dont bother with anodizing they just spray their coating of choice in the millled out area.

[ElvenSoul]

Some people like them shinny! There is a home alluminum bluing like process...sometimes it works.

http://www.brownells.com/.aspx/pid=4941/Product/ALUMINUM-BLACK

[yari]

as long as your not submerging it in salt water or another electrolyte you will be fine. if you do put it in salt water etc, you could see galvanic corrosion. id use some paint.

[bigbob76]

Thanks for the info guys. I used to have a few ARs before I got so absorbed in our AK thing. I think maybe it is time for a lightweight carbine and a scoped special purpose rifle.

[Lostsheep]

I agree with everyone here that not annodizing will not be a major concern. I have several with raw FCG pockets.

That being said, Aluminum WILL oxidize:

[kcstott]

I agree with everyone here that not annodizing will not be a major concern. I have several with raw FCG pockets.

That being said, Aluminum WILL oxidize:

I was going to say the same thing

[DarkSoul]

I have finished a few 80% lowers for myself now, and I have always had them anodized after the milling process. I have a good hookup down the street from my shop, I just give the guy a twenty, and he throws them in with an existing batch. I always bead blast them, and prefer to anodize after to act as primer, and then they will usually get painted. I am doing a full AR build right now starting with an 80% lower, Ill post up the build when it all done, including anodizing and Dura Coating.

"Plain" black anodizing should not add any thickness to the part, so the only thing you have to worry about is if it is "hard anodized"

[kcstott]

We did all our work first then had them hard anodized. I cut a touch over size to compensate for anodizing growth.

That said a 80% that is already anodized is way cheeper then sending it out after the fact.

[Intimid8tor]

We did all our work first then had them hard anodized. I cut a touch over size to compensate for anodizing growth.

That said a 80% that is already anodized is way cheeper then sending it out after the fact.

What did you cut to. I am getting ready to start cutting and all will be hard anodized after they are engraved and milled.

[Jason_2111]

Hammer/Trigger pin hole wear is the main reason to go with a good type III hard anodizing. If you're going to be shooting it a lot, that's a lot of rubbing the hammer pin and trigger pin will do to the inside of the pin holes.
Eventually, that could change the geometry between the two holes and distance between the hammer and trigger. That leads to double fires and other such malfunctions.
A solution is to use the non rotating hammer/trigger pin sets. With those, there's no wear... so you can paint/plain anodize/leave naked/whatever.

However, all of this becomes moot if the rifle you build never fires more than a couple thousand rounds.

[Jason_2111]

If you're going to leave a completed 80% naked... you should invest in one of these for it.

http://www.bravocompanyusa.com/KNS-Precision-Non-Rotating-Trigger-Hammer-Pins-p/kns%20trigger%20hammer%20154%20pins.htm

[Nathan Krynn]

What did you cut to. I am getting ready to start cutting and all will be hard anodized after they are engraved and milled.

Stick to 5/32 on the trigger and hammer. The selector hole is 3/8 and if you want to go all out ream to .376 but most safeties move freely at 3/8.

Nathan

[Joewy]

I have one I made 20 years ago. The whole thing is raw 7075 and it hasent corroded one bit.