On Sun, 01 Apr 2007 18:35:22 +0100, Alex Coleman
wrote:

On my rather old tube of 'regular' Araldite it says it is ok for metal.


It is OK for metal.

If this is so then why would I ever use one of those 2-part adhesives
sold specially for metal? I mean the sort of thing that is usually
coloured grey and can often be bought in car accessory shops?

Sundry other reasons. If it's what I'm thinking about they contain a
lot of inert filler, it helps filling holes and gaps. The grey colour
is to convince the proles they can fix holes in grey metal with it.

I need to glue an aluminium ring (about 1.5 inches diameter and about
4mm thick) to a plastic base. There will be some light to moderate
stressing of this arrangement when it is in use.

I figured the Araldite was just fine for the plastic but what about the
metal?

It's fine on aluminium per-se.

Less so on plastic, and it depends which plastic.

Set araldite is brittle, if the whole assembly will deflect under load
the joint may break up.

You may need to look further.

DG