Cutting openings in sheet metal ducts.

Page 1 of 2  
I need to cut 2 rectangular openings in an existing HVAC supply and return ducts.
How can I do this?
I've tried using a power jigsaw with a metal cutting blade -- big mess.
I see things like power shears when I do Google searches, but that seems like a whole lot of money to spend to just cut the 2 openings.
Are there any hand tools or cutting chisels that will work for this?
Any other suggestions?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
BETA-32 wrote:

sure, just get some GOOD tinsnips. then you just need to make a hole big enough to get the snips in and it will cut surprisingly easily.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Another vote for tin snips. Quiet, safe and accurate (once you get the hang of it).
I ended up with good ones from a the Snap-On truck that used to stop by the place I worked, when I was doing custom car audio installations a million years ago. If nobody here offers any specific brand names for "good ones", Snap-On is a safe bet. http://www.snap-on.com/
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
JoeSpareBedroom wrote:

Tin snips.
a
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
My HVAC man uses tin snips. Novel concept eh? Take a screwdriver and hammer, make a hole, snip away.
s

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 21 Oct 2007 20:01:18 -0500, "Steve Barker LT"

Visited the HVAC parts supplies shop recently. Saw a strange 12 inch screwdriver like tool that has a sharpened V shaped notch just behind the 1/2 inch blade. So I asked what for and how does one use this tool?
The tool is used to cut openings, straight lined or curved, in HVAC sheet metal ducts. Use the front of the blade to punch a slot hole into the metal. Hook the notch over the sheet metal. Hammer on the flat of the screwdrivers's shaft just behind the notched part. The notch will cut cleanly along the path of the blows.
Ingeneous!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Here's a DIY video on how it's done. Although this is for a circular collar, its similiar for a rectangle.
http://www.youtube.com/watch?v=gSN6L2KgDNA

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the youtube.com video link.
I guess tin snips it is, since that's the unanimous view. I didn't even try them because I thought that would never work, but obviously I was mistaken.
Thanks everyone.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What? Why do you think they existed? For cutting pizza?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

For some reason, I was thinking that there would be no easy way to get tin snips into the metal and cut along the line without mangling the metal. Then I watched the video and -- DUH -- I realized that I could just make the first entry cut in the middle of the area to be removed, and then approach the actual cut line from an angle and do the cutting from there. I am not usually this dense.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Buy red and green shears. Use the red one while using your right hand, the green one for when you're using your left hand.
--

Christopher A. Young
.
.

"BETA-32" < snipped-for-privacy@beta32bcghfd.cbd> wrote in message
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Make sure to get the ones with the right color handles.
There are three different types with a corresponding handle color (I don't know what color goes with what). One that cuts in a clock wise motion one that cuts in a counter clock wise direction and one that cut straight. Pick the one that works the best based upon the circumstances.
http://en.wikipedia.org/wiki/Tin_snips
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Instead of tin snips ask for aviation snips. There are 3 types, one that cuts to the right, one cuts left and one cuts stright. The handles are usually color coded as to which way they cut.
Here is a place to look at them:
http://www.mytoolstore.com/klein/1102s.html
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

return
I have always called that particular tool "Aviation Snips". I thought tin snips were the ones that look like heavy duty scissors. In a pinch I have used BX cutters on sheet metal and they worked well except the handles are shorter. Consequently you get less leverage with them.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

This could be an excellent opportunity for him to convince the wife that he needs to spend $400 on a power tool, even if it's overkill. http://www.internationaltool.com/boschnibblers.htm
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 21 Oct 2007 20:41:31 -0400, "BETA-32"

Get a one inch hole saw and drill the corners out with it. Use tin snips to cut the straight lines and finish by squaring the corners with the snips. I've done this several times.
The hole saw will be dull after a few holes so dont expect to use it fir your fine furniture later.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Had a humidifier installed a gazillion years ago.
the nice fellow had a metal tool with a V shape opening, he drilled a hole in each corner, then put the v tool in and hammered it, cutting the metal, FAST and easy, the rough edge was totally covered by the humidifier, so appearance didnt matter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hand tool to use is sometimes called Aviation snips, or Aircraft snips. Has mechanical advantage to make cutting metal much easier. Don't get the long jaws tool. Will easily handle most duct work steel.
May leave the metal rough and edges rough. Go to Automotive store, or sears, and get auto body and fender work tools, and there are small hand held anvils, called 'dolly blocks,' IIRC. A set of body work tools may out of your price range.
Just went up to Sears, (which in this rare case the craftsman tool might be OK.) they look like are starting the holiday sales with a set of aviation snips for a reasonable price. If you go to Sears, stick with craftsman line on this. Looks like cost will be reasonable come November. Most BORGs carry aviation snips. I like brands: Wiss and Stanley. Have used Klein, seemed OK.
Phil
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I make a hole in the middle of the drawn out rectangle then cut an X out to each corner, trim the end tips off the 4 "pie shaped" triangles, then fold them over into the duct to create a reinforced edge and crimp the fold with Robogrip pliers all along the way. The doubled up edge gives more material for the sheet metal screws to grab into when you are eventually screwing on the trim grate and makes the hole edge very strong and rigid. I'm not a sheet metal worker, maybe others know better, but the few holes I've made came out pretty good.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

get a hand nibbler. you need to drill a hole to start the cut,though.
--
Jim Yanik
jyanik
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.