There are solutions and there are workarounds. Workarounds should only be used when all other options are unavailable.
My thought is, if you need the tool once, you'll probably need it again. Any tool under $200 is worth owning.
I believe knowing and having experience with multiple methods to obtain the same result are very useful, some of us don't live up the street from Home Depot and such techniques may prove invaluable when out at sea.
If you wanted to you could also Make one out of delrin and plywood. Use a hole saw for the bend radius then find a router bit that matches the tubing for the Grove. Use a Square piece of delrin for the bending arm block. You could probably put one together for less than $50. If you wanted to invest the time.
My forced air diesel heater came with 3/16" OD copper tube for the fuel line. I've never worked with this stuff before. It shipped in a 12" diameter roll. Can I put a smaller radius bend in the tube without having to buy some kind of exotic pipe bender gizmo? I watched a YouTube video about working with copper tube, and they used a tube cutter that scored the tube around and around until it broke off. Is that way better than a hacksaw? And, it looks like I also need to buy something to de-burr the newly cut end, right?
Buy a decent tubing cutter. Consider buying two, the normal kind and the close quarters kind. Cheap tubing cutters are likely to be dull, likely to deform the remaining tube, and sloppy enough so that the cutting wheel tries to cut a spiral path... Not an advertisement, but I’m satisfied with my Ridgids.
I routinely use a band saw, a radial arm saw, a cutoff wheel in my angle grinder, or a cutoff wheel in my Dremel. Then clean up / square the end with a disk sander. Then deburr with a pocket knife. Seems silly? Faster than the usual tubing cutter, which is nice when you’re cutting more than one.
Buy a decent tubing cutter. Consider buying two, the normal kind and the close quarters kind. Cheap tubing cutters are likely to be dull, likely to deform the remaining tube, and sloppy enough so that the cutting wheel tries to cut a spiral path... Not an advertisement, but I’m satisfied with my Ridgids.
I routinely use a band saw, a radial arm saw, a cutoff wheel in my angle grinder, or a cutoff wheel in my Dremel. Then clean up / square the end with a disk sander. Then deburr with a pocket knife. Seems silly? Faster than the usual tubing cutter, which is nice when you’re cutting more than one.
X2 on rigid cutters. I also have a nice Lenox that cuts very well.
I'll second or third that work arounds are to be used when you are stuck out somewhere and to get going again you do what is needed to get going.
Poor practice when done as a normal practice.
These tools are not expensive, although not cheap, and will do a good job for you. All you need is a couple goofs to make them worthwhile.
The mini cutters are almost essential when working in close quarters as it is not always possible to pull the tube out to where adequate room is available.
As far as sand, soapy water and so on goes that , to me , is a work around. I've done that too but NOT on any fuel system or hydraulic system as it is difficult to remove ALL residue and ALL residue needs to be gone or other trouble will appear especially when working in cramped quarters where you may not have a good compressor or other good means of getting that debris out.
Decent tools, not fancy, won't put a lot of debris in the tube.
Head on down to the local NAPA or similar and get a tube bending kit and cutter. You may want to do double flaring depending on fittings so shop accordingly. Tight radius bends are doable and kit should include various dia. Springs that act as manderal benders when slipped over your tubing thus allowing kink free bends.