Thread: Impatience?
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Old October 19th 14, 08:47 AM posted to rec.radio.amateur.homebrew
Lostgallifreyan Lostgallifreyan is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 613
Default Impatience?
Brian Reay wrote in news:1207878279435369714.592439no.sp-
:

The ideal finish is anodise and dye (at least I'm pretty sure it is
anodise, perhaps another treatment, certainly dye). A very good finish and
durable. I don't think it is practical at home, partly due to the pre-
treatments. You often see this on commercial alloy products, which have a
very thin, silky, finish. Things like Karibiners used in climbing.

Sulphuric acid and electrolysis... I considered it... But anodising is best
left to those weho specialise in it. I already have acetone, MEK,
isoproponal, ferric chloride, in flasks and cans in my home. I decided not to
temp fate by adding lots of strong acid to the collection.

As far as aluminium's finish goes, why not just leave it bare? Not so pretty,
but it won't change much over a decade or two because all anodising is, is an
acceleration of the natural oxide layer formation (with dye fixed into any
porosity to make it look better). Once that layer is there, being the second
hardest natural mineral known, it just sits there unless something can break
through the thin layer by compressing the soft metal underneath.

One thing I have seen is old TV aerials in advanced corrosion so indications
of worst case real conditions can be known from those. They tend to thin, but
less so in recent years, less acid rain about.. Where they do fail is in
galvanic corrosion where cheap ferromagnetic steel bolts were used on them.
Most clean lengths of bare Al seem to last a very long time despite looking
very frail.
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