ALL SCI-FI

[Brent Gair]

Fer cryin' out load...it's July. Why a Christmas thread?

Well, it's like Xmas movies and songs. You can't wait until December. You have to get things rolling during the summer.

Having recently taken up the art of casting, I'm trying to expand my capabilities. I've cast some model parts using components from commercial kits but I wanted to make my own creation. I figured a small raygun could be pulled from a one-piece mold. This could be done "full size" but mold-making material isn't cheap so I want to learn on smaller pieces before I invest in big projects. I decided that small rayguns would make nice little sci-fi ornaments.

Step one was to make a master. Since this was done in a one piece mold, I wanted to design the raygun with soft edges and no place that would hold bubbles during the casting process. And that would make it easier to pull from the mold. The body of the gun is maple with a basswood fin and grip. The gun was assembled and sealed with black lacquer.







The point of casting is that multiple copies can be easily made. After spending a few days putting the master together, I was able to pop these two out of the mold in less than an hour. The rough appendage at the front of the gun is where the polyurethane resin is poured into the silicone mold.



I decided to make the "barrels" separately for a couple of reasons. They would complicate the molding process and complicate the removal of the master from the silicone. And, by making the barrels separately, I could add some variety to guns.





This finished gun gets a coat of gold paint. A ring attachment to suspend the ornament from a tree is made of stainless steel.

[Gord Green]

Beautiful!
Great effort, keep it up!
I'm anxious to see what you can do !

By the way, check out Adam Savages site on youtube - Tested, for similar efforts.

[Brent Gair]

Thanks, Gord.

Hey, I just tried an experiment.

Obviously, I want to move up to larger projects. One problem with larger castings is that the amount of material required goes up exponentially as molds get bigger. Doubling the volume of something requires eight times as much resin. Big things get expensive and heavy.

I just cast another little raygun but I tried "slush" casting it. Rather than filling the mold completely to produce a solid model, I used a smaller amount and rotated the mold while the item was setting. Instead of using 28ml for the raygun, I poured only 16ml into the mold which would result in a slightly hollow casting.

I weighed the new casting in comparison to my remaining older casting. Conveniently, it turns out the plastic weighs 1 gram per milliliter. So the new gun weighs 16g vs 28g. That shouldn't really affect the strength of this piece...it's pretty "chubby" and the walls of the casting should be quite thick. The polyurethane resin used is exceptionally strong.

And this resin only has a pot life of 3 minutes so you only have to rotate the mold for a few minutes before the resin sets up.

This should be helpful in economically producing larger pieces.

[Robert (Butch) Day]

Brent, are you doing just one or are you going to do different guns?
_________________
Common Sense ISN'T Common

[orzel-w]

[Brent Gair]

[Brent Gair]

[Brent Gair]

Here's a quick picture of the inventory this morning.

There's the wooden master in black. The finished gun in gold and the two raw castings. The neat thing about casting is how quickly copies can be made. When I decided to make the experimental slush casting last night, it only took a few minutes to gather the material and pop a complete gun out of the mold.

[Robert (Butch) Day]

[Krel]

[Brent Gair]

Here's a silver version. Note that I made an aluminum barrel for this one.

[img][/img]

[Gord Green]

I'd really like an update of your projects!
Lot'sa promise here!

[Brent Gair]

I'm doing a lot of "brain storming" for my next project.

I want to do more complicated subjects and advance to two part molds.

One problem is that the mold making process requires a lot of silicone which is not cheap. I currently have a fair amount of polyurethane plastic left which allows me to make items but I need more silicone in order to make new molds. I have put this on my Xmas wish list .

Currently, I have molds for three items: Bride of Frankenstein head, Bride of Frankenstein body and the ray gun.

I'm researching new projects .One idea is accurate improvement parts for the old Aurora/Polar Lights Lost in Space robot. This could include new legs, arms, neck...even a new torso if I'm ambitious. I'm also considering casting a small model of the saucer from THIS ISLAND EARTH. I have several other ideas.

Furthermore, I'm acquiring items such as a digital scale and inexpensive paper cups so that I may measure resin by weight instead of volume...this will save clean up time and is considered more accurate for small amounts of resin.

So my resin casting efforts are still highly active...but I'm currently planning projects and acquiring items to make things more efficient.

I haven't posted a picture of the Bride of Frankenstein body yet but I will do so shortly.

[Brent Gair]

Ok...here's a picture of the Bride's body cast in resin.

BTW, this is also my first attempt to post an imgur link. Photobucket has been super slow for me. They seem to have found a way to circumvent my adblock and their site now crawls.

I pulled this cast of the body (from the Aurora/Polar Lights Bride of Frankenstein) from a one piece mold. That was probably too ambitious. Note that most of the fingers have been amputated. Trying to get the resin into those tiny spaces in a one piece mold was asking too much. It's not a big deal because I can use some epoxy putty to rebuild them. This is part of the learning process...I now understand the limits of the one piece mold.

[Gord Green]

Looks good Brent!

It is a learning process. but your results show your up to it.

Thanks for sharing!