Cutting Cardboard Tubing
Laminate-faced cardboard tubes can be tricky to cut. Here are some tips. March 10, 2008
As part of a store display I am making, I have to cut heavy walled cardboard tubing with a paper laminate on the surface. I am trying to do this on my radial arm saw and cannot get a tear-free cut. Does anyone have an idea on how to cut this material cleanly?
From contributor T:
Round items can be difficult to cut cleanly without supporting their entire outside diameter. Cardboard tubes may pose even more problems as they tend to unravel if cut wrong. I might try making a block of wood with a hole in it that matches the outside diameter of your tube. Mount this block against your fence so that you can pass the tube through it with the side of the saw blade just skimming the face of the block. You might even want a block on both sides of the blade if both sides of the cut are important.
Another thing to do is get a melamine sawblade. These blades have a high alternate top grind and a negative hook angle. This blade should cut very cleanly on both sides of the cut and with the negative hook angle it will not pull on the part you are cutting as much as a standard blade may. A bonus feature is that melamine saw blades are made with C4 grade carbide which will extend your cutting life, especially in glue laden cardboard.
From contributor L:
Wrap the tube with the green or blue masking tape where you plan on cutting it. Use a good sharp blade designed for plywood or melamine. This should eliminate almost all the rip/chipout. The other option would be to make a jig that is the same radius as the tubing and put it on the tablesaw. Then spin the tubing within the jig while the jig/tube is over the blade. Keep the blade low and your chip-out should be minimal.
From contributor J:
I use my bandsaw, and hold the tube in a v-block. The tape idea is a good one, too.
From contributor E:
Make a v-block for your table saw and rotate/spin the tube as you cut. Make the cut shallow to score the paper and then deep to cut through the tube. You could also raise the blade into the tube before turning it.
From contributor F:
The bandsaw is the tool of choice, but a table saw works fine. A coarse blade is better than fine. If the tube is a structural one and convolute wound from Cubicon or Contour's or Shapes Unlimited, it will cut fairly clean but there will be some fuzz. Paint the fuzz with a PVA glue size, then let it dry and hit it with your ROS. It will be fine paint grade for sure. Spiral tubes are more trouble and take more time, but can work out. Cheaper to start with, but the extra labor may drive the cost higher.
From contributor K:
It is harder to make a jig to cut a few large diameter tubes on a TS or band saw than it is to take a hand held circular saw and just cut it for this kind of work? I usually just take a sheet of something like poster or matt board, and wrap it around the tube tightly so that the marking edge comes out flush on the line, and mark it with a pencil, then cut it with a circular saw.
Forget that there are guide marks on the saw base, and look around the saw, watching the cut, leave half of the pencil mark. If you wander from the mark, don't try to force the cut back over to the mark, but rather back up, and sneak back over to the line with a new kerf, and keep going.
Don't make a big deal out of this kind of work. Customers are looking at the product, not the ends of these tubes. If you have thousands to do, ignore this post.
From contributor R:
To cut a tube on a TS, set a stop - the rip fence works - and push the tube into the cut. Turn the tube, pull the top back toward the operator while pushing the bottom into the blade with the fence or stop as a guide... simple. Thousands cut with this method.
From contributor U:
What about using a Reed pipe cutter with four sharp wheels and rotating around the tube while tightening the cutter?