First, we'll look at Windia. The costume was all YummyGamorah. I made the sword! So, naturally, here is a shot that showcases it :3
The sword was made mostly out of fiberglass and foam. This was my first experience with fiberglass, and I have to say, it was a pretty positive one! I was always afraid of fiberglass, and thought that it was incredibly expensive. As it turns out, it's not so hard, and not as expensive as I thought it would be.
My lovely friend Josh at work offered to teach me the ways of the glass (and to lend me his garage in which to do it), so I took him up on that immediately. He uses fiberglass for auto body work, and is very familiar with it. Here is a quick and dirty explanation (via text wall) of the basic process, tools, and techniques I used to take the sword to completion.
I showed some progress photos of the sword in an earlier post, including tips on creating it.
After carving the sword out of foam (which was easy, fun, and extremely messy), I covered all of the foam in clear packing tape. This is not the time to get the super-ultra-thick-magic-packing tape. You want the thinnest, cheapest stuff you can find. The thinner the better. As thin as possible with still a reasonable amount of sticking power.
The goal is to cover all the foam so that the resin doesn't eat it (nomnom). Cut little pieces to fit in tight spots and around curves. I'm sure there are other things you can cover the foam with, but this was a quick and dirty solution, which also happened to be inexpensive, and effective. Very shallow detailing can be brought out later after you put the bondo coat on.
Next, the fiberglass is applied. The fiberglass sheets and resin came from the hardware store; it's near the paint, glues, and solvents. You can also find it online. You will also need some disposable mixing cups, cheap paintbrushes that you can throw away, popsicle sticks (or similar) to stir with, and a LOT of disposable gloves. Change them often. Never be without them.
You cut some strips of the fiberglass fabric, lay it on the foam, and start soaking it with the resin, which you've mixed up according to the package directions (right?). Use the paintbrushes to really get it saturated with the mix. Dabbing is better than strokes, as stroking with the brush can cause fiberglass "hairballs" which make things lumpy. If you get some of these, remove them.
Work quickly in small batches of resin, as it will begin to set up within a few minutes. When this starts to happen and the resin in the cup gets very gloppy, toss it and start with a new cup of new resin mix. Continue this until all surfaces of your foam are covered.
If your conditions are very humid, damp, or cold, (ours were all three :| ), you may need to add a little extra hardener to the resin. Beware of adding too much, as it will ruin the resin.
Allow the resin to cure fully as indicated on the package. You can see here some shots of the sword after it's been completely fiberglassed (the fiberglass is still curing here). You can see in the first shot some holes in the foam from where the resin got underneath the tape. The fiberglass will form a hard shell, so these holes won't matter, but you can understand how it would be bad if the resin were applied directly to the foam surface.
After that, you cover the fiberglass in a thin layer of Bondo or other body filler using a little plastic scraper (sold next to the Bondo). This fills in the texture of the fiberglass and any imperfections. Spread it on as thin as you can, but remember you can always sand it off; it will just take a very long time if you glop it on.
After the bondo sets, sand. Sand forever. Sand until you can sand no more. I recommend a power palm sander if you can get your hands on one. Finish it off with finer grits and by hand in tricky spots. Use a dremel to put in some shallow details. If you sand through to the fiberglass, stop there.
I filled in any holes with some paper mache pulp, which I then sanded again.
I used some DAS clay from the craft store to add the spiral details.
Finally! Once everything is smooth and clean, I used regular acrylic paint from the craft store to paint it up. I dry brushed on the grey areas on the blade; I wanted it to look like it was wooshing all the time, since Windia uses wind magic, and her sword is basically a wind sword. Once everything was painted, it was covered in a coat of clear satin spray sealer. This makes it more durable.
It's probably my favourite thing that I've made.
I hope these tips are helpful if you're going to make your own prop using fiberglass. This post is a little poorly written and a block-o-text, so I apologize for that. I usually try to be more organized and concise, but I'm clearly not in the mood for that.
I also apologize for the lack of fiberglass progress shots; there was no one to take them when my hands were covered in fiberglass gunk.
I think the sword complemented Sarah's excellent cosplay very well, and it was a great prop for her to pose with.