I had submitted an instructible on this before but it did not present very well so here is the revision.
My Daughter challenged me for a prop for a character she was cosplaying as in San Japan :3 in San Antonio, Texas 2010. She was cosplaying as Shana who is armed with a flaming Katana. I didn't want to make a typical paper mache or wooden prop with flames painted on and an actual flaming prop was out of the question. LED lights then came to mind but the idea of resistors and imbedding the lights into the prop without them looking like Christmas lights was leaving a bad taste in my mouth. An idea using plexiglass, acrylics, and my strobe flashlight then came to mind. So from challenge to brain storming to blue print to construction I present to you my instructible.
Step 1: Materials
These are the materials you will need:
1) A sheet of plexi glass 1/4 inch thick and 3 feet long. You can get away with a using a shorter peice (cheaper this way) and cutting peices you canconnect together to make 3 feet, but this weakens the integrity of the blade.
2) Clear transparent acrylic plates (orange, yellow, and/or red). The flatter the plates the better. These will be used to mimic the shape of flames. I shopped the local dollar stores and found what I needed, otherwise you can find these at Walmart.
3) 1 inch PVC pipe and a cap. You will need about 9-12 inches of pipe, depending on the size of your flash light.
4) I have a Mag Lite XL100, costs about $35. If you have a Mini Mag you can buy their IQ switch and LED light conversion to turn it into a strobe flashlight (this would be cheaper even if you bought a brand new Mini Mag).
5) PVC pipe cutter or hacksaw
6) Coping saw or scroll saw
7) Small spring clams
8) Liquid Nail Perfect Glue 2 or similar glue (Super glue does not work very well)
9) Dremel (if you have one) is always handy in any project
Step 2: The Blade
Draw a line along your plexiglass to give you a blade approximately 1 inch in width and cut it out with your coping saw. You can use a plexiglass cutter, but with a peice this narrow it is difficult not to break your blade in half while snapping it off. If you have a scroll saw it makes this step easier.
Step 3: The Flames
On the flat parts of your acrylic plates draw patterns of flames and your hilt guard (tsuba). Any pattern that suits you is fine, just remember the width of your blade, then cut the peices out with your coping saw (or scroll saw). Remember you will be applying these on each side of the blade, so cut duplicates of each pattern. I chose to alternate colors on each side.
Step 4: The Handle
Cut a length of PVC pipe 6 inches plus the length of your flashlight. Cut a 6 inch groove from one end of the pipe along the side. Cut a similar groove opposite the first. Make sure your groove is 3/4 inch in width so to accomodate your blade.
Step 5: Putting It All Together
You will now insert the flat end of the blade into the grooves in the handle and glue in place. Take your hilt guard (tsuba) and glue this in place as well.Take your acrylic flame patterns and glue them to both sides of the blade, using the spring clamps to hold them in place. While you are waiting for the glue to cure (you should wait a good 24 hours) you can decide to drill a hole at the end of your pipe end cap so you can access the switch of your flashlight easier or you can just keep it whole and take it off each time you want to turn on the flashlight.
Step 6: Flame On!
Once all the glue is cured and peices are secure, place your flashlight lense first into the handle followed by your PVC end cap. You can wrap your handle with cord or shoelace to add an aesthetic look. You now have a flaming sword.
Step 7: San Japan :3
Heres a couple pictures of the sword in use during San Japan :3 in San Antonio texas in 2010. I am just sorry you cant see the flame/stobe effect in a still shot.