Installing some lower parts I have removed some anodizing (small flecks) on the lower receiver. Is there anything I can use to touch this up?

Sharpie or a flat black pen.

What is Sharpie?

Birchwood Casey Aluma Black






Really?  

Sharpie

This stuff works great...Aluma Black

Sharpie for my AR.




AND WHAAAAATTTT?????

J-

Birchwood Casey Touch-Up Pen

Sharpie marker color it black. it works great.

Yeah, but it is a paint that wears off quickly. Use the Birchwood Casey Aluma Black pen.


Mikey

I've also used the Birchwood Casey Aluma Black, it works great.  A sharpie will fade and/or dissolve with cleaners and wash away.

From what little research I've done, there is no way to "SPOT" re-anodize an area where the anodizing was damaged.  You'll just make a mess of the rest of the anodizing coat trying to do it.  There is spot anodizing equipment, but its only for aircraft landing gear, cost and expertise looks like its impractical, besides it repairs the coat to prevent corrosion, probably makes the repaired area look worse than it was before.

Besides, the TypeIII hardcoat that is on the receiver now is a process you can't do at home, it takes really expensive hi-tech equipment under a very precisely controlled process, you can only do TypeI/II and that is much weaker than Type III, plus it make a mess of the rest of the coat.

All you can do is cosmetically fix the dings and scratches, the Aluma Black does a good job doing that.  It will help prevent corrosion, but it won't offer the hard layer of protection the typeIII anodizing does.

I tried Aluma Black... didn't do much.  Sharpie works the best for me.  Wait for it to dry and coat it with some gun oil... I was surprised how long the stuff lasted.

Did you thoroughly clean the area with Isopropyl Alcohol and let it dry before applying the Aluminum Black?

It does state the Aluminum Black finish color and results will vary with different types of aluminum and conditions, so its likely it will NOT always give the same results in all cases and maybe a sharpie will do a better job in some cases.  Considering how cheap Aluminum Black is (yea, more than a sharpie pen though) its worth a try before going to the sharpie.

 I'm still laughing at the "What's a sharpie?"

To the OP's credit, he probably just didn't recognize "sharpie" when it was presented in the same context as "AR15".  The two really don't make much sense when used in the same sentence like, "use a sharpie on your AR15".  To someone who has never done it, he/she would be like "WTF?".

I like the Birchwood Casey flat black touch up.  Have had very good luck with it when used sparingly.

-Ty

Actually on a delta ring with a bad scuff, (Is the Delta Ring Anodized?) I applied it using the directions to the letter, looked good, but thought it could be better and did a second treatment over the first, an exact repeat and it came out so well, I can find the scuff anymore, even when looking closely.  That might be because the Delta Ring doesn't look like its anodized, it looks like it has a treatment/coating to give it the flat black look, maybe its the same treatment as the BC Aluminum Black?