80% lowers and treating the raw ALU

CalG · Oct 20, 2016

I'm sure this is "material dependent", but what is the suggested treatment for the freshly exposed Alu (6000 or 7000 series) after machining a Mil-spec anodized 80% lower.

Certainly sending out for re anodizing is NOT the desired option. Lots of risks and the FFL hassle etc.

A good coat of paint seems like a workable option. "baked on". I hear that high temp "wood stove" (VHT) paint is as good as it gets.

Anyone have any FIRST HAND experience with corrosion?
Seems like a good thing to know about. Cleaning after every range session , it would be nice to feel like you were doing it right...;-)

If it were going on an aircraft, I would "acid etch and alodine"....;-)

JNieman · Oct 21, 2016

This is part of the reason I really don't care for 80% lowers. I really only care for the anodized finish.

I think it depends on "what's raw?" - were the pin holes already in there and anodized? Did you just have to mill the FCG pocket? Screw hole for grip? That will make a difference.

I wouldn't want raw pin holes- that's about the only real wear-surface on a lower. What had to be machined? If it's nothing CRITICAL then you might just get it all Cerakoted along with your handguard or w/e else you want, for aesthetics, and to provide a little better protection from dents/dings. I don't think -corrosion- is going to be an issue, necessarily.

MetalCarnage · Oct 21, 2016

I'm working on a couple of builds right now where I'm planning on using a Cerakote finish Cerakote Coatings It takes a bit more to prep the surface as you need to sand blast it. Also, I just got in a small "powder coat" oven from Eastwood for the baking of the lowers.
- http://www.eastwood.com/eastwood-be...e=&network=g&gclid=CM6Misfx7M8CFYOGaQodHQcL2A

It'll be a bit before I'm ready to finish them as I'm a bit backed up at the moment but I'll post after I'm done with them.

Not much help,

-Ron

mkd · Oct 21, 2016

Anodize kits are readily available and not very expensive, but more than just buying a finished lower.

SOP would be to strip and re-anodize.
2 cents

CalG · Oct 21, 2016

Are there any particular sensitivities of alu. to GPR?

I clean fire arms with "lamp oil", it's a good solvent, it leaves a light lubricating film, and the scented kinds smell good. ;-)

So every thing gets stored with a protective film that has worked just fine with "steel and wood" for over 55 years.
Not so sure about this "aluminum and plastic" stuff. ;-)

tdmidget · Oct 21, 2016

A clue to what "GPR" is would help. Most of us don't speak in abbreviations.

wesg · Oct 21, 2016

You're not going to strip hard anodize and be left with anything usable to reanodize.

CalG · Oct 21, 2016

tdmidget said:
A clue to what "GPR" is would help. Most of us don't speak in abbreviations.

GPR= gun powder residue, It's a TV catch phrase.... ;-)

CalG · Oct 21, 2016

wesg said:
You're not going to strip hard anodize and be left with anything usable to reanodize.

I would not even CONSIDER that option. A good anodizing job is an art form!

AeroE · Dec 3, 2016

Slop on alodine and paint. Folks fool around with home anodize set ups, but a quart bottle of alodine is low cost, easy to use without special equipment, and will treat a bunch of aluminum gun parts.
Paint can be all over the map from Rustoleum to baked polyurethane or epoxy finishes. Rustoleum is cheap, and if the gun is a usin' gun, paint from an aerosol can is easy to touch up or even redo.

GeneT · Dec 4, 2016

I have anodized several lowers, without problems. The problem I foresee with an 80% anodize is that the previously anodized parts (assuming they were also dyed) might leak dye into the bath, ruining the electrolyte and perhaps the color on the previously anodized part. (The color might recover in dying the newly anodized surfaces). Neither Alodyne nor paint will do anything about wear, but in a pragmatic sense, most AR's aren't going to see enough wear for it to ever matter.

VHT is a cross-linked ceramic like Cerakote. They will hold up much better than most 'regular' paints.

GsT

traditional-tools · Dec 4, 2016

CalG said:
I would not even CONSIDER that option. A good anodizing job is an art form!

Just take them to a local anodizing shop that does Type III.

If they are raw you could go with just about any color you like.

Cerakote is good tough stuff, but if it's not prepped properly it will chip easily. Ultimately it will chip if used regularly. For that reason I like anodized.

paracongo308 · Dec 4, 2016

And if you decide on type III anodize make sure your pin holes are oversized. If not you will need a carbide reamer to open them back up.

Royldean · Dec 5, 2016

traditional-tools said:
Just take them to a local anodizing shop that does Type III.

Except if they are no longer 80% (ie, fire control group pocket and holes are present), then the "local anodizing shop" must have an FFL to do the work.

RWO · Dec 5, 2016

I sent my finished lower to http://www.usanodizing.com/ The Type III Mil Spec finish was perfect. They are fully equipped to coat your raw aluminum lower with about anything else if you don't like the Mil Spec look. They have an FFL.

paracongo308 · Dec 5, 2016

RWO said:
I sent my finished lower to http://www.usanodizing.com/ The Type III Mil Spec finish was perfect. They are fully equipped to coat your raw aluminum lower with about anything else if you don't like the Mil Spec look. They have an FFL.

Type III anodize finishes are very limited to colors. The company I use offers 2 colors, black and what they call natural which is a grayish finish.

JNieman · Dec 5, 2016

AeroE said:
Slop on alodine and paint. Folks fool around with home anodize set ups, but a quart bottle of alodine is low cost, easy to use without special equipment, and will treat a bunch of aluminum gun parts.
Paint can be all over the map from Rustoleum to baked polyurethane or epoxy finishes. Rustoleum is cheap, and if the gun is a usin' gun, paint from an aerosol can is easy to touch up or even redo.

Alodyne or conversion coating only treats the surface to promote adhesion of paints and other coatings and to limit oxidation/corrosion. It will in no way make the surface harder or tougher like anodization does. That's the main reason receivers are anodized.

CalG · Dec 5, 2016

As lowers are sometimes made from plastic "these days", the hardness would seem to be a secondary consideration.

My objective is corrosion protection, and frequent cleaning and oiling is filling all needs.

The take down pin holes for the lower I used are finished , anodized, and fit the pins PERFECTLY.
Only the trigger group pins are susceptible to abrasion wear. Corrosion in the firing group cavity is entirely different.

Cole2534 · Dec 6, 2016

I always figured that if I had enough time and money to wear out the holes from a firing schedule that I probably had enough time and money to bush the pins.

AeroE · Dec 7, 2016

JNieman said:
Alodyne or conversion coating only treats the surface to promote adhesion of paints and other coatings and to limit oxidation/corrosion. It will in no way make the surface harder or tougher like anodization does. That's the main reason receivers are anodized.

A lower receiver does not need a hard coat. The only wear surfaces with motion are in the magazine well, and the magazines will remove the anodize anyway, if the owner doesn't in order to get the magazines to drop free.

I get a chuckle out of the idea of using hard coats to improve wear under motion of aluminum parts. It's a "better than nothing" solution.

The pin holes benefit from good fit, not the hard surface. The loads are so small that there is no real benefit from hard coat in the holes, and the down side is poor fit until the holes are reamed.

80% lowers and treating the raw ALU

Diamond

Titanium

Stainless

Stainless

Diamond

Diamond

Titanium

Diamond

Diamond

Cast Iron

Cast Iron

Diamond

Banned

Stainless

Cast Iron

Banned

Titanium

Diamond

Diamond

Cast Iron

Similar threads