wrote in message
...
On Nov 8, 3:58 pm, "LLBrown" wrote:

Here is what goes on.... I bend a thin wall brass tube to shape then I
have
to melt the bending medium out of the pipe with a torch. This causes a
black scaling to show up on the outside of the pipe. To remove this I
dip
the pipe in a 50/50 mix of muratic acid and water. This in turn plates
the
pipe with very thin copper that I have to buff off.

I'd be more concerned about annealing the tube during the melt-out,
countering
whatever work hardening happened during the bending. Unless an
annealed
condition of that particular part has been recommended by Sheldon the
Cat, its
dent susceptibility makes it somewhat less desirable.

But what about just buffing the scale off in the first place?

The annealed condition is ok. I tried buffing and it can be done, it is
just a question of time. 10 seconds in the bath takes the scale off and
then I just scrub it with a plastic scratch pad to take the worst of the
copper off, its very thin. The whole project is buffed when finished.
Using the acid really saves time and effort.

LLB