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Am I correct assuming only 2024 is clad coated not 6061?
Jean-Paul
"larry" <larry.a.schurr@boeing.com> wrote in message
news:1144337281.238097.292960@t31g2000cwb.googlegroups.com...
> >Can you explain what you mean by Clad coating?
>
> Well... Aluminum is a whitish-gray material, not slick and shiny like
> the sheet metal you buy. The sheetmetal product, and much plate stock,
> is almost always 'clad-coated' and to my knowledge, not available any
> other way. That shiny stuff is the 'clad' which is simply more
> aluminum that has been pressed tightly to eliminate natural porosity.
> Of course, the *process* has changed over the years but the result is
> the same: shiny and slick sheetmetal.
>
> Beneath the clad coating is "raw" aluminum. This has been the bugaboo
> of corrosion problems among many. Raw aluminum is quite reactive to
> air and water and protects itself with an oxide layer of white powder
> (that also turns mysteriously black when you handle it -- kinda weird).
> Depending on alloy, once the raw surface is exposed, the oxide layer
> can go quite deep -- often deeper than the sheetstock IS. The clad
> coating, while still aluminum, keeps corrsion at bay to a much greater
> extent because it reacts far, far, slower than 'raw' aluminum. Once
> this clad is gone, all bets are off.
>
> Sanding or etching removes this coating pretty much every time. Once
> removed, you're gonna hafta treat that surface pretty quickly with
> aluminum specific coating (like alodine). Another poster quite rightly
> pointed out that color isn't supposed to be very 'deep'. "Well-done
> fried chicken" brown is too deep. "Light Honey" brown might be more
> appropriate. Gotta go, getting hungry alla sudden :-)
>
> Larry
>
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Re: Question about Alodine 1201
