Question Pros / cons to applying a 'protectant' to milled aluminum AR receiver pocket?

RatSeng

RatSeng

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Hi all. 'Protectant' as in BC Aluminum Black, or etching primer + rattle-can matte black paint, or Aluma-hyde, or etc... or, just leaving the milled aluminum bare.

Really appreciating the helpful threads in the forum. Thanks in advance!
 
I'm not much help on this topic, but someone here will be!

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You can leave it bare aluminum if you want. the aluminum oxidizes pretty quickly to form a protective layer of it own.
I have used BC Aluminum Black on black receivers, and spray paint on colored receivers. All are good.
 
@no4mk1t - Thanks for this. Great to know that the BC Aluminum Black and paint options are OK, as well as just keeping the bare aluminum. Was just looking through your earlier posts related to this. Really nice work.
 
I don't know of any aluminum etching products that are compatible with epoxy based rattle can spray paint like Aluma-hyde, and the finish won't grab well to aluminum without etching.

Regular enamel or urethane based rattle can paint companies do sell chemical aluminum etching products that are compatible with their paints, but even after cured those paints will wipe right off with gun cleaning solvents like Hoppes #9

DuraCoat might sell the correct products for what you're wanting, but I don't have experience using them. Maybe a poster here named Mooner will chime in. He has done a lot of painting with DuraCoat.

If you don't have access to blasting equipment to mechanically etch the aluminum, then I'd just leave it bare.
 
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Thanks much, @Dave . For the etching + paint option, I was considering Rustoleum self-etching primer (link to Amazon) and Rustoleum acrylic enamel (link to Amazon). But, if gun cleaning solvents would easily take all of that off, then... yeah, bare or BC Aluminum Black sound like the better options.
 
Hey, RatSeng, check out the thread below. I have no experience with it, but cerakote makes a clear product for aluminum that doesn't require etching.

AR10 - Keep polished Aluminum or Coat it?

I should be able to polish it up a little better still. Pondering whether I want to keep it as is or do some sort of coat on it. I like the look, but it will stand out against standard black upper and lower parts. Not sure that I want it to stand out as a DIY. Have the Dog Fight Ink stencil...
www.patriotgunbuilders.com www.patriotgunbuilders.com
 
no4mk1t said:
You can leave it bare aluminum if you want. the aluminum oxidizes pretty quickly to form a protective layer of it own.
Click to expand...
THIS! ^^^^ The only reason you would need to coat the machined surface is aesthetic... :) You shouldn't be able to see it with the gun assembled. There is a reason they use Aluminum Oxide in sandpaper... ;)

My concern with many other coatings would be they may dissolve due to solvents or lubes used in gun cleaning/maintenance.

Ideally, the part would be anodized which adds "extra" layers of Al2O3. This is usually done with a "raw" billet or forging. For you to have an anodizer do an 80% part for you would require the anodizer be willing to let you hang around and observe the entire process so that your "chain of custody" is not broken. I know an anodizer who is also an FFL and he would do a raw 80>100% but it would have to be serialized somehow so it could be logged in/out.
 
I left mine (3) bare aluminum. The trigger pocket has remained relatively clean and shiny. I use oil sparingly on triggers. Too much lubricant attracts dust, grit, other funk. I should mention they were Cerakoted before I milled them.
 
Don't laugh. It works. Place milled receiver (or any raw aluminum part) in dishwasher, wash high heat or pots and pans mode. Use regular detergent pod. Leaves behind a nice, uniform oxide layer with a light tan patina.
 
Aside from bluing, I've never found anything that comes close to the durability and chemical resistance of Cerakote.

Duracoat, Alumacoat and similars... it's paint. Goes on thick. Chips and rubs off on the edges.

I am by no means a painting pro. With a few exceptions I have always sent my guns to a pro for finishing. I suppose that if you really dont care what the gun looks like those rattle can alternatives are OK. Then again, if you dont care what it looks like why put any finish on it at all?

My firearms are pretty boring. Typically I stick with factory colors and finishes. Or a close facsimile.
 
Do you have to finish the bare aluminum pocket after milling? Not really. For a rifle that is just going to the range and home again, it will not be a problem.

For a rifle that sees hard use, then yes, doing the whole anodizing drill is the best for long term wear and corrosion protection. Middle ground is just paint (epoxy based and baked on finish). Keeps the corrosion down.

Most of mine are baked epoxy paint as the basic finish inside and out, though a few have an anodized finish under the paint. Just started doing this to get a receiver closer to the specs of a commercially made one. (Anodizing after machining gets all the holes through the receiver, better than just paint alone.)
 
Thanks everyone! This conversation certainly leveled-up my understanding of the different options available.
 

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