In some upcoming posts, I’ll be discussing fountains (gerbs), wheel drivers, line rockets and black powder rockets.
These projects will require parallel wound paper fireworks tubes. To understand the difference between parallel and spiral wound fireworks tubes read the heading above the tube section on the Skylighter website.
There are lots of different diameter and length tubes listed in that section. Why would we need to know how to cut and treat those tubes?
If you look at product number TU1065, you’ll see a typical one-pound, 3/4-inch ID, 1/4-inch wall tube that is 30-inches long. Those tubes currently cost $54.59 for 25 of them, or $2.18 each. Four 7-1/2-inch tubes can be cut out of each of them, and each of those typical length rocket tubes would end up costing you $0.55 each.
Now, if you look at product number TU1068, you’ll see those same tubes, but 7-1/2-inches long, selling for $40.71 for 50 of them, or $0.81 each.
That’s a pretty big difference. If we know how to cut our own tubes out of the 30-inch long ones, we can save some money.
Additionally, some devices like short-duration fountains, stinger rockets, and other types of rockets require tubes of lengths that are different than 7-1/2 inches. Knowing how to accurately cut various lengths of tubes will be necessary when making those items.
Also, if these tubes are treated with a hardener, they will have a higher burst strength and will be more resistant to the flame burning through the tube side-wall while the device is functioning. So, it’s nice to know how to treat the tubes to accomplish this.
You might be saying, “Ned, why don’t you just use a hacksaw or coping saw to cut the tubes by eyeballing the crosscut?”
I have two main goals when cutting tubes: I want a very square cut which runs at exactly 90 degrees across the tube, and I want a straight, smooth cut.
I have used a, power miter, wood working saw to cut many tubes. This is a quick way to accomplish those goals. But it has some disadvantages. I don’t use such power tools in my fireworking shop, so to use that tool I have to go to the shop where it is located. It is also a bulky, heavy tool, which is not conducive to taking to pyro events where I might be cutting tubes and making various devices. Power tools are also dangerous, and can “grab” tubes when they are being cut unless one is very careful.
In the past year or so I’ve settled on a tube-cutting method which accomplishes my goals but which does not have the disadvantages I’ve listed above.
I found a plastic, Stanley, hand-sawing miter box at Home Depot, which has black plastic cams for locking a work-piece in place during sawing. Unless I’m just making one quick cut, I screw the miter box to my workbench to hold it securely in place during cuts.
I also found a nice, sharp, clean-cutting pull-saw at the same store. This saw cuts the tubes easily, quickly, and with very straight, smooth cuts.