Cutting spiral pipe tool and making wye questions

[Mike Heidrick]

Guess I should figure out how to cut the 8" and 6" spiral ductwork correctly.

I have read about using:
Plasma (do not own)
jigsaw

Can you use a couple other tools:
Metal Chopsaw?
4" portable metal bandsaw and rotating the pipe?

Anyone use a nibbler, shear, or offset shear - which of these is the best?
This sounds like a tool that should be corded or pneumatic - which is best?
Anyone use cordless shears of the Dewalt offset shear?

Anyone make their own Wyes with spiral pipe at all? I have seen the site for PVC. I do have a small mig welder as well. Any advice here?

I have seen a ridgid 6"-8" hinged pipe cutter - will that work for spiral pipe?

http://www.affordabletool.com/ebay/images/products/0300-023-8in-hinge-cutter/images/01.jpg

[Rick Potter]

I had a post on this a while back. Got several answers. It was about a month ago.

Meanwhile, I asked a heating guy what he used.......Sawzall. When I said how do you get the cut straight he just looked at me funny and said it didn't have to be perfect.

Rick Potter

[Brent Grooms]

Mike, good timing since I did some expansion/changes to my system. I use a hacksaw to get a hole in the pipe, then use a jigsaw. I use a hose clamp and a sharpie to get a straight line. I also use a "clamp" made of a couple of pieces of scrap ply and some plumbers strap. It makes things a bit safer while cutting shorter pieces.

[Tom Klass]

We use a 4" grinder with a cut off disc, those abrasive type that are about 1/16th. thick. works like a dream. We cut from 28" duct to 4" duct use masking tape to follow once you made the mark for length.
Tom

[Scott Shevnock]

I cut my 6" with my chop saw...I made a "sled" out of scrap plywood to support the pipe on both sides of the disc and cut as deep as I could and spun it. I started with a pair of manual shears and it just took too long.

[Ben Cadotte]

14" abrasive saw (cheap one from HF). Make small V jig to hold it. That way can roll it to cut other side. And will have a nice clean square cut. Quickest and cleanest of the other options. If you have a use for it, a multicutter saw works wonders (14" chop saw with metal carbide blade). They are about $400 though. Well worth it if you cut enough metals.