Donwill wrote:
Dave Plowman (News) wrote:
I need to secure a boss made from aluminium rod into a hole made in the
wall of an aluminium tube. Of course welding would be ideal - but there's
little load on it. And I'm not sure I can be bothered finding an
aluminium
welder. Unless I could do it myself with my MIG. Which I'm not much good
with on steel. ;-)
Car body filler? Epoxy? Any special precautions?


De-grease, abrade to remove oxidised layer, degrease again, then
Araldite.

They stick aeroplanes together with it, so maybe it's good enough for
sticking a sensor. ??? =-O

Araldite went out of favour before 1978 when I transfered within the
aerospace industry. What followed was a product called hysol. This was
available as an adhesive and a liquid shim. Liqid shim had powdered
slate, or powdered aluminium mixed in, to give it more body.

Both Araldite and hysol depended on the same thing, they had to be used
on aluminium that had been anodised and epoxy primered. The bond to the
ally and paint was 100% and the weak point was the bonding agent itself.
I have seen many joints that have failed and it has always been the
bonding agent and not the paint. I think others have pointed out the
problems with a bare aluminium bonded joints.

(Just got back from 2 long drives, brain is about as much use as a bowl
of mashed potato at the moment)

So going back to Dave's problem, I would say weld, braze, or solder, for
a long joint life.

Dave