On Sun, 09 Apr 2017 08:52:32 -0500, Ignoramus14657
wrote:

On 2017-04-09, Carl Ijames wrote:
I'm guessing the white stuff is your basic hard water deposits, calcium and
magnesium carbonates and/or sulfates and/or other salts. It always tempting

No, it is expanding urethane foam.

to start throwing acids at the problem to dissolve them, but then you are
going to have a big volume of hazardous waste to get rid of. How about
cutting the tubing with bolt cutters,

Way too thick for bolt cutters, over an inch thick, and inside the
tubing there is one more tubing (it is a heat exchanger). So it is
like a double tube.

and trying something like a small air hammer with a wide flat tip to
vibrate off as much of the white stuff as you can. Maybe hit the
coil before you cut it up to knock off big chunks, then each length
after you cut it up. Finish with a wire brush. As much as I love
chemistry, mechanical methods are almost always faster :-). Save
any acid for a final polishing step only if really needed.

I was really hoping that there is a blade for a circular saw that
would work.

i
Copper is "sticky" so a circular saw isn't ideal. A portable band saw
would be ideal, but a recip would do the job. Either way, there WILL
be some "fun" involved. I also have a "shear" that would "likely" do
the job, but you would need to uncoil everything first.