Aluminum Finish

[JPSmit]

Think I have all three

I think i have 2 but i can't remember

 

[Guest]

Think I have all three

I think i have 2 but i can't remember

Remember what? :crazy:

 

[dklawson]

Anodize is usually called hard coat.

Soft coat is called iridite, which is a similar process, i.e. the ozidation of the surface layer...but a thinner layer. Scott in CA

Sorry, that is not correct.

Anodizing (both soft and hard) is an electro-chemical process similar to plating. The difference between soft and hard coat are some process steps and the thickness of the resulting aluminum oxide layer. As its name implies, hard coat is "hard" and thicker (often as much as 0.001"-0.002" buildup). Soft coat is thinner, typically less than 0.001". Soft coat is what you will see on things like old backpack frames and AN fittings. Hard coat is what you will find on things like cookware.

Because of its higher cost, hard coat is not the "default". There are Mil specs applicable to both, soft coat being "type 2" and hard coat being "type 3".

Iridite is a totally different process (chromate). It is a non-electrical process leaving a very thin film which offers only limited protection to aluminum. It is often used where the surface must remain electrically conductive.

 

[The_architect]

I personally have no experience with getting things anodized but I have read that castings, such as windshield posts, are difficult to anodize because of impurities in the aluminum. Extrusions such as Bugeye cockpit surrounds are fine. Did this get mentioned anywhere in this thread? Sorry if it did. Any opinions on this?

A friend who polished a my cockpit surround pieces did a fantastic job. Then without asking me, he clearcoated them. Ugh. They just don't look good. I installed them anyway, and will strip them someday, perhaps.
Charlie