I’ve been dreading cutting out the doors and hatches. I don’t have a small circular saw like some people have shown, and despite my Wife’s well-founded belief that I’ll buy any tool I don’t have and might use again, I didn’t go out and buy one for the straight parts. I thought about the jigsaw and it’s weakness – the blade is not well constrained, and can wobble around quite a bit. I thought of many schemes to stabilize the blade and started with a 3/16″ aluminum plate cut to the same size as the jigsaw base. The base had four countersunk screws in it to hold a plastic insert so I had a means to attach the plate. My bandsaw blade had a kerf just slightly narrower than the jigsaw blade, and I opened that up with some sandpaper. The goal was to have a slot JUST wide enough to let the blade function, but no more. I was prepared to add more pieces above the plate to lengthen the support slot, but didn’t have to. You can see from my photos that the blade didn’t wander (I did a little bit, but that’s another story) and the cuts were thin and followed the lines.