Posted: Tue Jul 28, 2009 8:43 am
It won't 'weld' (dissimillar metals) but may 'stick' if you manage to over heat it. It needs to be thick enough so as not to melt through - we had a 6 inch square piece about 1/2" thick in the fabrication works I used to toil in - I guess the thickness helps to spread the heat and stop the arc melting one area.
Not having a lump like that here, I tend to use an old Thor hammer for small holes - it has the advantage of a nice long insulated handle as obviously whatever you use - it gets HOT!
Oh yes, technique: if you want to fill up a hole someone's drilled in a dashboard, say - (obviously there's a limit to how big the hole is before it makes more sense to plate it!) you'd just clean back to bare metal, place your copper behind and 'paint' the weld into the hole in a circular motion (working inwards) fairly low power setting. Remove the backing copper and grind front for a dead smooth finish (aluminium oxide sanding disc works wonders, and if the weld was neat, you shouldn't need hard grinding disc at all).... simple!
Not having a lump like that here, I tend to use an old Thor hammer for small holes - it has the advantage of a nice long insulated handle as obviously whatever you use - it gets HOT!
Oh yes, technique: if you want to fill up a hole someone's drilled in a dashboard, say - (obviously there's a limit to how big the hole is before it makes more sense to plate it!) you'd just clean back to bare metal, place your copper behind and 'paint' the weld into the hole in a circular motion (working inwards) fairly low power setting. Remove the backing copper and grind front for a dead smooth finish (aluminium oxide sanding disc works wonders, and if the weld was neat, you shouldn't need hard grinding disc at all).... simple!