Made my first fiberglass canopy 'shell' and need some guidance. The canopy will form the superstructure with windows cut out and sectioned for opening and closing. I used 2 layers of a medium weave glass-don't know what weight. Before I take it off the plug and cut-how do I get a good smooth surface? A bunch of dimples where the resin 'ran'. It will need reinforcing in places, like joints. Add more resin on top and sand, reeinforce inside? How many layers of glass for strength? It's about 11" long, 4" high, 3 1/2 wide-if that helps.

Since you made your canopy using a male plug rather than a female mold, your only choice is to use sandpaper, filler, and possibly more cloth to get a smooth finish.

Can't speak to the "reinforcement required" issue without knowing what weight cloth you used, what your cutouts will look like, and what your structural needs are. If you can post a photo or two and some more info, we could help.

Canopy will be cut a rear 1/3 for hinge and at windscreen to open upward. Will see if photo will work!

Well, I tried to send photo-wouldn't work. Took a pic with digital cam but the pic shows a .psf format within the ArcSoft PhotoStudio program I have which will not be accepted,and I don't know how to convert-or if you can- to jpeg or format acceptable by RCU

Canopy will hinge upward from about 1/3 from rear to windscreen.

This suggestion is not easy, but.... consider sanding it smooth, put a layer of .75 ounce fiberglass cloth over the frame, use pieces of mylar pressured against the cloth. With adequate pressure the mylar should cause a smooth finish. Thin mylar cut into side strips should conform to the shape. As Mike said, without knowing the weight of the original cloth its tough to comment on strength issues.
Mike

Thanks for the comments guys! I have automotive type filler-rather thin stuff in a tube, don't know if that's compatible with epoxy resin or not. The cloth I used was 3" tape I've had for years and don't have a clue as to weight. It is a tight weave rather stiff, the thickness of what I've got now is heavier than the typical ABS cowls, etc. that comes in kits. If I use sanding and filler, then stiffen the inside at the hinge and a 'ledge' at the top and sides of the windscreen for closure that should be strong enough-shouldn't it?

I've done parts that way, and if you're careful, it will work. You can make hatch flanges on parts that didn't have them, by using strips about 1/2" wide of 1/64th plywood, epoxied to the inside surface of your canopy. (1/4" glueing surface and 1/4" flange) Just be careful not to distort your canopy part by inducing stresses with the flange. (I recommend pre-bending the canopy frame material before installing it, so it's just a plain glue joint and not a "stress causer".)

If you're just making one part, all of this is ok. If you plan on repeating it, you might consider the more tedious, but more precise and repeatable method of making male plugs and female molds, with your frames and flanges already built in.

Let us see your results here when you're done!