Effects Of Removing Anodizing From 6061-T6 and 7075-T6 Aluminum Via Media/Bead/Sand

AbidTalwala

AbidTalwala

Joined
Dec 20, 2011
Messages
62
Hello Fellow Members,

Okay, so I was hoping to find some answers to a few questions I've been having about anodized aluminum. Now from what I've read here and there aluminum is stated to be corrosion resistant but at the same time it is prone to pitting, cratering and eroding.

So I have a couple knives with aluminum handles as well as a couple flashlights, all made from aluminum that's been type III hard anodized. Needless to say the anodizing is wearing from use and I don't like the look. So I wanted to blast the handles with some type of media and remove the anodizing, but before I did I wanted to know if my aluminum is going be destroyed by erosion, or pitting, or cratering.

If any of you know if it's okay to leave 6061-T6 and 7075-T6 aluminum bare and untreated or not coated please chime in and let me know why we coat aluminum if it's okay to leave it raw and natural.

Thanks guy, really look forward to this discussion and any information that is provided.

Best regards,
Abid.
 
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Are you going to polish it after? I don't like the look of sandblasted aluminum. It's kind of grey and picks up dirt and grease.

There is also galvanic corrosion to consider. I don't think that would be huge any more than the pitting, etc. Read this.

http://www.aluminiumdesign.net/design-support/aluminiums-corrosion-resistance/

I'd worry more about the aluminum just being soft and scratching and dinging easily. The nasty sandblast finish is the biggest thing.
 
Soaking them in Easy Off oven cleaner will remove the anodizing.
The exposed aluminum will scratch easily. You can burnish it with 0000 steel wool.
 
Aluminum, like steel has different alloys that have different rates and behaviors related to corrosion. That said I think you'll be okay, I haven't noticed much corrosion of unfinished high strength alloys in knife applications, might want to look out for galvanic corrosion between the aluminum and steel hardware, but even then it shouldn't be as bad as most high performance steels and pivot washers. Just don't leave saltwater or sweat all over it for a long time.
 
At my job we make tons of stuff in 6061 for the military. We bead blast everything we send to them.
One time, in the 15 years I've been there, we had parts returned damaged from corrosion.
They were mounted on the coast in Australia and coated with salt spray from the ocean daily for months.
So, unless you plan on treating it like that, I'd say your good.
 
@davek14, thanks for the link and for your contribution. I don't think I'm going to attempt to polish, I was thinking something along the lines of blasting the aluminum and then stone washing it in attempts to create a type of working finish that will hide ware. I know of the gray color you speak of and I don't know if I'll be a fan of it until I see it so I'm hoping it'll look fine once I stone wash. Thanks again, and I'll be taking a look at that link shortly.
 
@Bill Deshivs, thanks for tip, I will look into that, certainly sounds like an good way to get rid of the anodizing. But I still have curious to see what the sand blasted aluminum will look like as well as the texture. Thanks again.
 
@yoda4561, Thanks for the information, I will certainly be looking out for any corrosion between the two metals, and I'm always making sure I clean my gear off after its been exposed to saltwater or even sweat but thank you for all the information and your input.
 
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@leifjl, Thank you for your input and speaking about your experience with 6061, it certainly makes me feel better at blasting the aluminum. I certainly wont be using my gear in anyway close to what you described so I'd glad I'll be okay. Thanks again.
 
Aluminun will actually oxidize. It developes a white sort of chalky appearance when it's been exposed to the elements long enough. Old motorcycle parts made of aluminum are evidence of this. I'd recommend some sort of coating to replace the anodizing. Cerakote has been highly recommended in the gunsmithing community.
 
The active ingredient in Easy Off is sodium hydroxide, also the active ingredient in drain openers like draino, which will do the same thing.

Drain openers now have chunks of aluminum in them because sodium hydroxide dissolves aluminum as well and makes a gas, which supposedly helps un-clog drains.

Keep an eye on it, when the aluminum turns black, the anodizing is gone.
 
@woodwrkr221, thank you very much for the input. I think I know exactly what you're talking about, that oxide levels does give aluminum that almost white, gray appearance. I'll definitely think about adding some coating later after I see how the parts turn out. I do like Cerekote, Thanks again.
 
@69_knives, thanks a lot, you clearly seem to know what your talking about and I will definitely heed your advice if I decide to go the Easy Off or drain opener route. The information you provided is good to know, thanks again.
 
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