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21HK
August 18, 2017, 17:08
A couple of years ago I was playing around doing some acid etching on a 2" steel ball. I liked the way it turned out and thought it might be interesting to incorporate this on a project gun some day.
http://i.imgur.com/VBRe5AM.jpg

As you may have seen recently in the market place there have been quite a few AR's that had their fair share of department use and would fit right in with what I was looking for.
When this DPMS came up it had just enough road rash that I didn't mind taking it a step further. This, if you can believe, is the first time I've ever taken an AR apart. I had to borrow a wrench and barrel vise ...and watch a video, seriously! I guess it's just never been at the top of my list.

...anyway, back to this thing.

Short version:
Disassemble, file/sand out the deep dings, mask and sandblast the areas to be etched. I didn't want to have a sharp line between the original finish and the etched area so I didn't blast next to the tape line.

Next was to apply a random spray pattern with webbing paint in the areas to be etched. The paint acts as a mask, what's not painted gets etched. I didn't time it but I would say I only left the etching solution on for no more than 5 minutes, maybe a little longer in some and a little less in others. Remove the paint mask with thinner and lightly sand with a fine paper to highlight the areas that were not etched.

The painting/masking and etching process was done twice. This allows the areas that are not covered by the webbing paint during both etching processes to etch a little deeper giving a layered effect. The darker areas are the deepest. Once I was satisfied with the look of the pattern I did another light sanding with 1000 grit paper.

A light quick application of etching solution was applied to the whole area with no mask again and rinsed. Rinse is a mix of baking soda and water. The etching solution acts similar to Aluma-Black and darkens the whole area again followed up with another light sanding using 1000 grit paper. This ensures the deepest areas would remain dark after the final highlighting.

Scotchbrite or steel wool would have a tendency to remove the blackening from areas that are below the original surface.


Before
http://i.imgur.com/ZoiHhpm.jpg

http://i.imgur.com/g8NrgBR.jpg



The furniture was media blasted which gives it a more of a grey color. I also removed about 2/3 of the nub on the A2 grip. I also did some additional distressing on areas with a scotchbrite.
I'm still contemplating about doing something more on the furniture, not sure what yet, maybe some stippling.

Thanks for looking!
...like it, hate it?...it's all good.

After
http://i.imgur.com/0Mq8jCA.jpg

http://i.imgur.com/kX0W4zG.jpg

http://i.imgur.com/nTjbp4p.jpg

http://i.imgur.com/oPrSy9S.jpg

http://i.imgur.com/1y6pk3X.jpg

http://i.imgur.com/mV8yKTd.jpg

paulo
August 18, 2017, 18:29
I kind of like it.

easttex
August 18, 2017, 19:11
Has kind of a SciFi movie look about it. Would look appropriate on the set of an Aliens movie set.

I like it.

21HK
August 18, 2017, 22:06
I kind of like it.

That's about where I'm at with it. Considering it's a first attempt at something like this I didn't really have a plan so I'm still on the fence about the overall appearance. Maybe it just needs drug down a gravel road to really give that "look".

Thanks easttex. I do like some SciFi stuff, Aliens for sure.
Not wanting to go "tacticool" with it but I may lose the nylon sling that came with it and possibly rework a couple of old HK G3 leather slings...I have some HK stuff around here somewhere.:wink:

Tuscan Raider
August 19, 2017, 08:00
Neat. Has that "mottled" look of a old retro furniture.

Any reason why you didn't do more above the pistol grip?

21HK
August 19, 2017, 11:29
Neat. Has that "mottled" look of a old retro furniture.

Any reason why you didn't do more above the pistol grip?

Funny that you mention "mottled" and "retro". I kind of like the old school look of bakelite. I "fakelited" the grip originally with paint but the pattern and color didn't do anything to compliment the etching that's why I ended up deciding to sand blast the furniture.

As far as doing more above the grip....etching or wear? Thanks for your input, let me know your thoughts.

http://i.imgur.com/s3oXf0b.jpg

ALL FAL
August 19, 2017, 18:03
" IF you Scratch aluminum, You Scrap aluminum" Old Pilots know this too, that is the only misgiving I have about the etching, for a truck gun is probably fine but for battle I could not trust it fully. Hope it proves to a cool way to Olden Up your gun. ;)

21HK
August 19, 2017, 18:13
Very interesting, I didn't know that...thanks!


....I'm assuming it jeopardizes the integrity?

John A
August 19, 2017, 18:49
The anodizing is there for a reason. If it wasn't, you can be sure that no manufacturer would apply it.

The biggest being with Type 3, is increased hardness. Grind down below the anodizing, is essentially the same as grinding down below the level for heat treating where the softer metal is.

http://www.appliedanodize.com/why/

21HK
August 19, 2017, 23:50
I'm sure any structural integrity hasn't been compromised as much as these two have.
All things considered it's not likely that I'll be needing this as a battle rifle any time soon, I hope! ...and don't plan on it being out in the harsh climate. Thanks for the input, it's appreciated.

http://i.imgur.com/Rzh8tGZl.jpg


http://i.imgur.com/qrQrx43l.jpg

hueyville
August 20, 2017, 09:39
" IF you Scratch aluminum, You Scrap aluminum" Old Pilots know this too, that is the only misgiving I have about the etching, for a truck gun is probably fine but for battle I could not trust it fully. Hope it proves to a cool way to Olden Up your gun. ;)

Would flat finish clear Cerakote or Gunkote finish address your issue while retaining the well worn "look"?

Trypcil
August 20, 2017, 10:11
The subtle mottling on that Pistol grip is very attractive to the eye - now if you could do the whole rifle like that you'd be onto something! :D
Not so sure that structural integrity due to acid etching, is necessarily compromising enough to be concerned about, alloys today are way different to what old pilots were flying - it be interesting to find out what exactly would fail! ?

fly2.0
August 21, 2017, 14:58
Funny that you mention "mottled" and "retro". I kind of like the old school look of bakelite. I "fakelited" the grip originally with paint but the pattern and color didn't do anything to compliment the etching that's why I ended up deciding to sand blast the furniture.

As far as doing more above the grip....etching or wear? Thanks for your input, let me know your thoughts.

http://i.imgur.com/s3oXf0b.jpg

I like that look ^^^^^^^^^^ :rolleyes:

jhend170
August 21, 2017, 15:41
I'm ok with the look. It's as close to a case-hardened look as you'll likely get with chemistry.

And some of you are WAY overestimating the effect of removing anodizing from 7075. If this was an issue do you think the BCG would be allowed to touch the inside of the upper or the receiver extension and create wear? Don't be silly.

Yes, it makes the surface harder and reduces the electrical carrying capacity, that therefore reduces or stops galvanic corrosion. Unless you're dunking your AR in the ocean on a daily basis and not cleaning it after, this isn't really an issue. If it were they'd all come with zinc anodes, now wouldn't they?

MistWolf
August 21, 2017, 15:43
I'm not a fan of artificially distressed firearms. Wear should be honest. Wear is earned. A rifle that has its finish worn because a Marine carried daily in war is or because Grampa used it hunting elk forty years ago is interesting. A rifle that was acid washed in the garage or dragged behind a mall crawler down a driveway is- well, dishonest. It has no appeal.

A word about aluminum. Scratching aluminum doesn't scrap it. Unless the scratch is too deep to blend out. Too deep to blend means that after blending out the scratch, there's not enough material left for the needed strength.

When scratched, aluminum starts combining with oxygen to form aluminum oxide, one of the hardest substances known to man. Aluminum does this naturally unless it's in a low oxygen environment or is constantly being exposed to chlorides. This makes aluminum a self healing metal. Aluminum oxide makes the surface of the aluminum resistant to abrasion and corrosion. It does nothing for the heat treat of aluminum or it's hardness. "O" aluminum is annealed and very soft and it still oxidizes. T6 aluminum will stay T6 even if the aluminum oxide is sanded away.

Aircraft skin is made from a variety of alloys, the most common being 2024 T3. Aircraft skins are not anodized. Aluminum used for aircraft skins are not anodized. It has an outer layer of pure aluminum, called AlClad, to protect the alloyed aluminum from corrosion. The AlClad will form a thin layer of aluminum oxide but the base metal is pure aluminum and very soft.

Anodizing creates a layer of aluminum oxide that is more uniform and thicker than the natural layer. Anodizing is only used on aluminum alloys. I suppose you could anodize pure aluminum, but it would give it much scratch resistance. Another way to treat aluminum is by anodizing. It's a chemical process that uses acid to oxidize the surface. It produces a thicker layer than the natural process, but not as thick as anodizing.

Anodizing is NOT BLACK. The black you see on your AR is NOT ANODIZING. It is a dye applied during the anodizing process. Anodizing turns the aluminum gold or a dull mottled grey. That's the color your AR would be without the dye. If the dye is worn off and the bare aluminum is gold or a dull mottled grey, the actual anodizing is still intact.

The anodizing process specified for an AR is Class 3 Type II. Class 3 specifies what anodizing process is used and how deep the anodizing is to be, what corrosion resistance it offers and how resistant the coating will be to abrasion. Type II specifies that the the surface will also be dyed.

If Type I is specified, no dye is used and the metal will turn gold or a dull mottled grey

21HK
August 21, 2017, 16:06
I liked the way it turned out as well but it just didn't work with the rest of the gun. All I used was a mix of rattle can paint and clear, any solvents would of probably taken it right off. The best thing would be to go with duracoat or something like that.
I actually did the handguard and stock but it was so overwhelming that I never even took a photo of it. Shortly after....10 minutes or so, it all went into the blast cabinet.

I worked from MrM1A1 photos to try and duplicate the bakelite appearance.

http://i987.photobucket.com/albums/ae355/4mulaoneguy/Retro%20AR%20parts/5F32BEC0-B2CE-494A-B79A-46EF577EECC2_zps9oxdsnnv.jpg

Better photo showing the color on the one I did.
http://i.imgur.com/ZayBo26.jpg