"Oren" wrote in message
...
On Sun, 10 Oct 2010 20:52:53 -0400, "Colbyt"
wrote:

I own most of the tools and would hate to buy a new one for this project
but
take your best shot at the best way and tool to do this and I will go from
there.

I have not actually measured it but I think the main trunk line I need to
cut is 12x18, might be 12x24. Standard gauge metal HVAC duct from 40+
years
ago. I have reasonable access on all four sides. Well that one side is
going to be a b**** but I can do it once if I must. Most likely, I want
to
return the duct to its original position after the project is completed..
I
might choose to step it up to make it easier on the next fat guy. But that
part I can figure out.

I can't unzip it at the seams without a lot of digging in 60+ year dried
dirt as the next seam is resting on the ground. Hey, I did not do the
original install. If I had it would be far different.

So what I want is a clean way to cut the duct without destroying the metal
on either side of the cut. As an example: much like cutting the four sides
of a wood box with a table saw.

Now to inject a little humor to the thread; the reason I want to do this
is
because my belly has grown to big and my back to bad to scoot under the
tunnel I made years ago in this crawl space. Did I mention I hate tight
crawl spaces.

Suggest a diet and die. There isn't time or the willpower to make it
happen. I got to get over there to figure out where the water leak is
coming
from. Go ahead and make your fat guy jokes if you must. Paybacks can be
awesome. -

How about and air nibbler?

Video:

_Harbor Freight Air Nibbler Reveiw and Demo _

http://www.youtube.com/watch?v=HZbBwJm7Ew8


That would be about 3 times the continuous CFM rate of my better compressor
but I sure like what I saw. Breaks are not a bad thing while working.

Colbyt