Aluminium reed staples

[Julia Say]

I've just been clearing up some piles of ...well...things that needed clearing up, amongst which were three or four knackered reeds from goodness knows where that I intended to recycle as staples.
When dismantled the "eye" end of the aluminium staple had oxidised considerably and there was white powder clinging to both inside and outside the eye.

This stuff is horrible. Before Alcan were obliged to clean up so rigorously they discharged it into the area round here and we have a layer in our loft from way back. Every time building work takes place up there it comes down, with deleterious effects on my / our breathing.

A reed staple only has a small amount on it, but nevertheless I think I'd not be inclined to use aluminium staples if its going to do that inside a reed.

Just a thought

Julia

[Francis Wood]

Brass will also corrode, but gold should be OK.

I once asked Archie Dagg why he used aluminium tube for staples. He told me that it was because it was easy to cut with scissors.
No corrosion detected yet in the small collection of Dagg reeds that have ended up here. Their problem is chiefly the adhesive used to attach the cane to the metal. It may have been fine when it was recently applied but age has done it no favours, and it now seems to be a mechanically unreliable brown goo.

Francis

[John Gibbons]

The salt in sea air will play hell with aluminium, especially if there is any less active metal in direct or indirect contact.
Was there copper wire in the bridle of the offending reeds?

John

[Julia Say]

Two of them had had flat copper bands, rather than wire, as bridles. These are mostly things that have come into the house in non-working pipes, or at the bottom of the boxes of said pipes.
We're only a mile from the sea here, but I haven't noticed the sort of effects from it that we got where I lived on the south coast as a child. With a huge Al plant also half a mile away, it was the oxide deposit that moved me to comment.

Yes I know almost everything corrodes, and I've had numerous lectures on the evils of verdigris and its causes , but I don't see my own brass staples behaving in such an unruly manner - even when left to their own devices for some time.

Julia

[John Gibbons]

You don't get much of a battery with one electrode brass and the other one of copper;
aluminium and copper work much better - and the aluminium will be the one that corrodes preferentially.
Just like the zinc in a galvanised bucket.

So the moral is that the metal of the bridle and the staple should be similar, or better identical, in their electrochemical properties.
If not and the assembly gets damp, especially in the presence of an electrolyte like salt, you will get huge corrosion problems.

John