On 26/08/2020 19:08, Mike McLeod wrote:
On Wed, 26 Aug 2020 17:03:47 +0100, newshound
wrote:

I can get the area clean no problem, but am inclined to leave it be as
a little resistance would be no bad thing, since it generates a
hot-spot when high current is passed through it, which is in this
instance at least, desirable!

I disagree. You will get the peak current density at the contact from
the constriction resistance effect. You do *not* want to include oxide
in the weld, because this will reduce its strength.