First time making props...not too sure on the process

[thedau]

hey guys

so I'm attempting to make my a costume for the first time. as part of the costume, I want to have a clear samurai sword that lights up. I bought a replica sword with a removable blade, so I can use the sheath and the handle. I already have a good idea of how to wire up the lights. the only problem is I'm not exactly sure how to cast the blade. the blade is roughly 0.15" thick, and 37" long. I was originally thinking I could do a single pour mold with a sort of a silicone putty and clear resin. however after some research and watching some tutorials I see a lot of people casting blades with a 2 piece silicone rubber mold. only problem I see with doing the cast this way is because the blade is so thin, it might be really hard to make it exactly the same dimensions.

would anyone be able to help and give some pointers on molding/casting the blade?

 

[Batt]

I've never cast anything but this seems like something I would rather shape out of clear plastic.

 

[thedau]

I thought about just using clear plexiglass, but I figured if I cast I can put EL wire inside the resin for a more even glow as opposed to having a small bulb in the guard

 

[Krel]

Couldn't you make the blade out of plexiglass, cut a groove along the top of the blade, and run the EL wire in the groove?

David.

 

[Kevin Gossett]

The issue with casting something that long and thin is it will likely break very easily. Typically something cast like that has some sort of support structure inside, like a metal rod or wooden dowel. Obviously, that won't work for you since it needs to be clear.

 

[thedau]

would a coat hanger help with strength? if I paint it white and frost the back of the blade, hopefully that would help hide it. also, 4mm plexiglass would be just as flimsy, no?

 

[ultraman]

if i had to do it....
1.) i'd use 2 pieces of clear acrylic sheet..
2.) cut out a front and back blade pattern
3.) dremel or router out a grove going down the center of one or both sides for el wire
4.) lay the el wire down the center
5.) super glue the sides together and clamp
6.) sand blast both sides of the the blade to defuse the light

-bang done :cool

 

[thedau]

would 2 sheets with a total thickness of 4mm still be as flimsy?

I figured if I frost the back part of the blade I'd be able to hide whatever reinforcement I put in there