I wrap a string around the pipe and draw the line. Then I use a cut off wheel to work my way around the pipe. Even if you are a tad off, the edges of the wheel will smooth it out. Just don’t use the wheel as a sanding disc if you will.
Works pretty well for me.
chad
If single wall, the pipe can usually be opened up and laid flat for a clean cut with straight shears (yellow handle or big straight shears). If the pipe is round you need to use both the red and green shears to cut a strip out of the pipe. The red shear cuts to the left, the green shear cuts to the right. But if used together to cut a say 1” strip out of the pipe, it will curl in front of the shears and allow you to make a nice clean cut.
Good snips if 24 gauge and snap-lock. NOT aviation snips, but good straight hand snips. Find an old Pexto or Niagara pair or else a newer set with aluminum body and steel blades.
Also power snips - not that Kett Type, but the Makita type with the two square blades. There are actually a whole bunch of shear types these days - some are nibblers, some scissor (Kett) types, and others use the square blades. Harbor Freight has some cheapies that may work fine, although I have always used the good ones since we were pros (Makita and Kett).
Welded pipe is always tougher, and may have to be drilled to start the hole or worked back from one end. The Kett type snips work well with a welded pipe.
Never used a hacksaw, although may have used cut-off on enamel pipe after scoring enamel. That is a whole ‘nother story.
Installing heating and ventilation systems, I’ve cut many a round pipe with aviation snips. If you know what you’re doing it’s pretty easy and they work well. True, I prefer to use my big straight snips, if I can open up the pipe and lay it flat. But a lot of folks don’t own the big shears and they are sometimes harder to find. A good set of Wiss aviation snips can do a lot in the right hands. But don’t buy a cheap knock-off set. They will be a PITA.
Be green is right buy decent snips and Wise brand is right up there Cresent is ok as well
No one has mentioned this but cutting metal requires protection if cutting by grinding or sawsall you need eye protection. Dealing with metal produces nasty cuts.
Decent gloves to protect your hands again a few seconds thinking some task out, just might save a trip to the ER
My beef with aviation snips is the relative short blade lengths and also many are serrated. The result is an edge that is less than clean, although with lighter ga. as Begreen mentions this may be OK.
We used Aviations to cut out of the round holes, etc. in fireplace block offs. There are also some offset aviations (like a duck bill?), which can do a nice job.
Good advise on the top brands. Don’t buy no-name shears if you can help it…...although I might try if it was a one-time job. A lot of flea markets (and ebay) sell the old heavy straight shears for $3. to $20. - they will last forever.
Elk reminds me that I pretty much gave up guitar playing when I worked with stoves and even carpentry. Your hands are usually recovering from small cuts at all times. The key is not to do the big cuts! Eye and hand protection are important if you want to live long and well.
I’ll only cut up to 22 ga with snips and prefer to go no lower than 24ga. Big bladed sheers are straight and only work on flat metal. If the pipe is already locked to round, and there’s no power nearby, this is the best way to go. (Note, this is single wall pipe only.)
Another tip to make the snips work even better is put a drop of oil on the cutting edge before starting. Makes them work much more smoothly. To start the cut, take a flat blade screwdriver and pound the blade on the side edge through the metal like a knife. It sounds crude, but is standard practice. It helps to use a nice screwdriver like a Malco 3/8” blade for this purpose. When your cut comes to the fold-over lock seam, either switch to a straight snip for the cut or carefully hacksaw the seam.
We used mostly 24 ga snap-lock…....there was no slip joints available. Back in the old days it was tough to convince folks to go for the Heat-Fab at double or triple the price.
However, today…with the stoves being so expensive, I would probably only carry the heavy-duty stuff if I had a store again. In that case, slips are often the right way to go. Still, there is always the odd install…....
1) You don’t have a tight Male to female Factory Joint.
2) what a pain in the a$$ NOT having Up and down adjustment trying to Tip the stove or what ever to get the pipe to fit into the stove collar and to the connection at the support box.
My time is worth more that trying to Make a slip or screwing around trying to get exact length of pipe and forcing it into place.
A 2608b 38” - 70” adjustable kit of heavy 22 gage heat fab only list for . $67.70 Takes only a few minutes to slip together
Connect to Chimney then slip down to the stove. go to page 37
Or short Adjustable 24” that has 16” of slip is only $20.50
But 95% of our installs we use Ultra black double wall. $164.60 for a 40” to 68” adjustable LIFETIME warantee pipe. double wall page 22
Given crimped pipe, you cut off the female end, and therefore usually have a factory crimp….and, of course, a set of decent crimpers is fine for the occasion when you don’t.
With insulated chimney, the pipe adapter at the ceiling is often a slip, giving the installer an inch or two to work with to drop pipe into a collar. If it is a situation where the pipe turns and goes into a wall, then you are not faced with that “tip the stove and wrestle” situation. But we have definitely done that more than once.
Back in the old days, we delivered and installed stoves into existing chimneys for $95. plus the black pipe, which usually ran about $25 total. Of course, the stoves cost $299 to $599, so everything was relatively cheaper. I see the wisdom of using the better stuff today since folks are spending thousands on the whole job. Still, there are a lot of replacement situations and lower cost installs out there…..I’m gonna have to give Rod a tour of Appalachia and the southern states, where blued steel stove pipe (26 ga) is still the rule…and you buy it in the hardware or furniture store. The stove itself is often an old Ashley that sold for about $125.00 when new.
Of course, it is hard to figure the numbers, but I would guess that 10x as much 24 ga stove pipe (in terms of length) is still sold as opposed to 22 ga and double wall. Of course, if we use just “specialty retail stove shops”, the figure would be less. There are a lot of stoves sold and updated “under the radar” from Ace, Lowes, HD, and many other sources.
