Alodining?

[un2xs]

A video mentioned alodining of aluminum parts. This is the first I have ever heard of this process. It seems to be likened to base coating.

https://www.creatingway.com/alodine-and-anodizing-coating/

Is this some thing to consider for paintball guns? Would this basically just be a base coat for some thing like cerakote?

[JeeperCreeper]

Alodizing seems to just be a coating, anodizing actually hardens a thin layer of aluminum into aluminum oxide, usually with dye added in the process that gets trapped in the pores of the metal

[ford]

Is this some thing to consider for paintball guns? Would this basically just be a base coat for some thing like cerakote?

It's cool that it allegedly doesn't change dimensions any... It sounds like it leaves a much more brittle coat than anodizing does. It still requires using an acid bath which is always fun disposing of properly. I would avoid.

[Ecapnation]

It's a prep step for parts getting painted..... It's also ugly, kinda yellow. Mostly used in military and aviation

[VonBraun63]

It’s a chromate coating for aluminum. It’s for corrosion prevention mainly but is also used for a base layer for paint. It’s very very thin and scratches easily. Depending on what alodine chemical number you use ( powder, premix, concentrate) it will come out anywhere between yellow and dark brown. It’s time, cleanliness and type of pre-etch sensitive as to how it comes out equal to the same parts. I use it everyday building lycoming and continental engines. Let’s stick with anodizing for all our paintball needs.

[gabe]

^^^What he said

It's a surface conversion chromate coating which basically just adds a cladding to the aluminum to keep it from corroding if it's bare or under a coat of paint. Very common in aviation for doing sheet metal parts like exterior surfaces of planes before painting.

Yes very much stick with Anodizing as it is a surface conversion FINISH coating. Alodine is a surface prep type coating for further paint on top.

VonBraun, very cool you work on engines. I work in aviation too in the manufacturing side for bush plane parts. Heard of the Alaskan Bushwheels?

[Surf2Live]

Alodine is the brand name for Henkel’s aluminum chemical conversion coat, commonly referred to as “Chem Film”. There are many different types of chem film including colored chromate, colorless chromate, and colorless non-chromate. The chromate versions contain hexavalent chromium and is disallowed under RoHS as a known carcinogen and is becoming less common on newer parts. The colorless chem film uses a trivalent chromium. The old specification covering chromate coatings is MIL-C-5541 and the new spec inclusive of non-chromate coatings is MIL-DTL-5541; for anyone looking for specifics.

The finished film thickness is specified by Severity Class and can be up to .001 in. (SC25), but is typically ~.0005 or less. This film is a purposeful oxidation layer created after an etching process. It does protect against corrosion, its primary function, but it is not a hardened wear surface like anodize.

Parts having threaded holes often are chem filmed first then anodized with the threaded holes plugged. This ensures the threads are not put into service as bare aluminum and have not gone out of tolerance (too tight) from the anodize buildup. Cutting threads to the upper tolerance limit can allow the thread to return to nominal after anodize if the threads require more corrosion resistance than provided by chem film alone.

Any other questions, let me know.