Build up the plug with 1/8" balsa on the bottom and back and flare into the plug as an extention to the original.
On the right is my vacuum box, this ain't rocket science guys. Is a pine box with a piece of PVC to accept my shop-vac hose, I use a peg-board surface with screen on top and window sealing tape going around the top that makes contact with the plastic. The frame is made of angle aluminum with legs made from .032 music wire, the plastic is held on to the frame with stationary clips. The key is to form a part on your plug and trim but, do not remove it, sand with 400 grit, you will be molding on top of that. Use a block to raise the plug off the surface so the radius does not become part of the final pulled piece and remove all dust particals from the plug and plastic.
I use .030 clear PVC and set the oven at 400 degrees, it only takes a couple of minutes for the plastic to soften, place over form and make sure you contact the seal then, turn on the vacuum. The next photo shows off the finished canopy, alls that needed now is to tirm and install.
I'm running low on the .030 PVC so if anyone knows where I could get some, let me know.
When I add the 1" Williams pilot, paint, seat and instrumentation panel, you'll get a better, overall impression than, what's viewed here but, you get the idea.
I quess I'd better get to tuning the engine and experiment with the pipe and tank setups. I'll probably use one of my older combat ships to do most of the tests. The pictures show the mandrels I've made up, the long one will be waxed with Partall #4 and PVA'd, the ring on the end is removable so it allows easier removal after it's layed up. I'll machine an aluminum headpipe which will be held on the mandrel by a threaded washer and then I'll lay up about 1" over it. It'll have some grooves cut into it to keep it from slipping. The converging cone is a male/female type mold and will also have an aluminum insert as the stinger. It'll have a couple of baffels and for testing , I'll use Epon 862 then, the final will be made of a higher temp, more expensive product from Cotronics that'll handle up to 500 degrees.