Rainfell Keyblade (casting something large with clear resin?)

[TheCosplayBunny]

Hoping I can get a little feedback as I dive into this prop making adventure!

Last year I created this Rainfell keyblade:

It was a rush job for a last minute cosplay but the reactions I got were great! Now that I’ve moved into a larger shop space I wanna try my hand at it again. I’ve already 3D printed my base, my plan is to mold and cast the blade and handle with a clear rod going through the center to hold them together.

A lot of people loved my use of holographic flake to simulate the “magic” effect, I really wanted to run with that on this one! I want to cast the “blade” section with a clear resin; tinted blue with a nice mix of flake. My biggest worry is casting something this large without a vacuum chamber (Bubbles, yikes!). I’m trying to get this as clear as possible and bubbles would really ruin the effect! I’m creating a platinum silicone two part mold, my question for you all is:

What can I do to reduce bubbles in such a large cast? Also, what are your light weight clear resin recommendations? I’ve heard nasty things about smooth on Crystal Clear and Smooth Cast 326 has pretty bad heat/shrinkage.

Any tips or alternative ideas for achieving this look are greatly appreciated!

 

[PlanetAlexander]

I'll give you a tip from my last failed molding attempt: if you don't have a vacuum chamber, put down a print layer of silicone first. This greatly reduces the chances of bubbles and grabs all the details. You can then add more silicone on top of that.

With the first half of the two part mold I made, I just poured the silicone in, which left out a few details and created bubbles. The second half I put down the print layer and it looks absolutely fine to me.

Oh, and that magic effect DOES look good! How was it achieved?