The first thing I needed to do to get ready for trimming the canopy was mark the center of the front and back. This is to make sure I consistently place the canopy in the same place every time I put it on the frame. There are two black marks that the manufacturer puts on the canopy that appear to be on the center(ish). That's what I'm going with anyway, since otherwise there is no way to actually find the center (measuring from the edge of the material very obviously does not find the center - it doesn't seem they care about centering the raw material on the form they use).
Rose helped me pull the canopy off again. I pulled the plastic back on the front edge and taped a cut line. I initially put a space heater under the canopy, but I found that the infrared heater did a much better job of warming things up. I actually had to turn it off part way through the cutting because of how warm it was getting.
Instead of using a cutoff wheel in my die grinder, I decided to use my oscillating multi tool. It's a little slower than a cutoff wheel, but it's much easier to control. The blade I'm using has very small teeth and vibrates/melts its way through the material really nicely. The big bonus is that while the cutoff wheel throws dust absolutely everywhere, the multi tool just creates some big, melted chunks and virtually no dust. Every foot or so I duct taped the pieces together for support. Most cracks I've read about happen when the cutoff piece falls away from the canopy because it's not supported before the cut is complete. After the cut was done, I put the sanding attachment on the tool and hit the edge with 80, then 120 grit to smooth it out. Once I have all cutting completely done I'll polish the edges, but for now all I need to do is smooth them out so there's no sharp edges. I'm going to have a lot of back and forth cutting before I reach the point of polishing.
Even though the instructions recommend cutting the canopy with it setting upright on its edges and held from spreading with 2x4s attached to the bench top, once I got to the long edges I realized that wasn't going to be a great approach. As soon as I started cutting, the heavy weight of the canopy made it push out and away from the cut (the cut piece being held in place by the 2x4s clamped to the bench). Ripe for a crack! I flipped the canopy on its back instead. This was much better since the only weight I had to deal with was the couple of inches of the cut piece. That was easy to control with duct tape.
All the edges were trimmed to the form mold lines with no casualties! Just for fun I bent the scrap pieces to see what it takes to actually break them. The material is far more flexible than I thought it would be. I had to bend the narrow pieces in half and then step on the bend to get it to break. When it breaks, it breaks in spectacular fashion though.
And now, back on the plane for the first iteration of shaping. It's kind of hard to figure out where to cut at this point. There are absolutely no measurements provided. I know the front windscreen needs to be cut at the curve of the material, where it comes down and then gradually flattens out. The flat part needs to be completely cut off. The problem is it's extremely hard to tell where that point actually is on such a clear canopy. I put tape down, then got down on my knees and marked as close to the curve as possible. For now I'm erring on the side of leaving it too long. I'll continue to chop it back little by little. The same is true for the curve from the front to the side. I've marked a gentle curve, but I know it's forward of where it ultimately has to be. I also taped off a little more on the aft end of the canopy - just chopping off the corners and creating a little more of a curve that matches the skin. I'm not bothering with this end all that much for now. Once I'm done with the front and it's been cut away from the rear window portion, then I'll figure out the right cuts for the back. The picture below is before I started the extra taping. Rose helped me pull the canopy back off. I think the first step tomorrow will be to pull the plastic back a little more on the inside and put tape in its place - easier to keep the canopy clean without cut junk working its way under the plastic that isn't perfectly adhered.
