Depedning on the gage of the metal, tin shears might be the way to go.
Drill a couple holes with a "step bit" and start from the hole.
Plywood can be used to make duct, though some of the HVAC guys here
would not be happy with me writing that. I'm thinking you could make
something that comes out later, next time you need to go make repairs.

Some supply houses have offset pieces, so you can run the trunk up or
down a couple inches. I doubt any of the premade pieces would offset 8
inches, though.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Colbyt" wrote in message
m...

Looks like the dremel or angle grinder is the clear winner here. The
diamond
versus the abrasive disc not yet so clear. I am concerned about the
sparks
in a confined crawl space but more than likely I can drape a tarp to
catch
them.

I own both tools and will test these on some scrap metal sometime in
the
next few days.

For whomever said it, if I rejoined these as it was I planned to
bridge the
seam with some screwed or pop-riveted metal and then tape the whole
joint
with the better metal tape. Bending new tabs for a seam strip would
shorten
the duct by two inches so that is only an option if I can offset the
last 5
feet.

What I really want to do is raise that last 5 foot of trunk by
patching in
an offset since there is a good 8-10" between the top of the trunk and
the
floor joists. There is no valid reason for it resting on the dirt the
way it
is now. Just a lazy HVAC person. Also they way it is now precludes
the
possibility of insulating it.

I will update this thread for the benefit of those who may follow it
later.


--
Colbyt
Please come visit http://www.househomerepair.com