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Colbyt Colbyt is offline
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Default Cutting a metal duc t-- what tool to use? Reply


"Colbyt" wrote in message
...
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. -


--
Colbyt



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
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