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Monday, January 19, 2015

A First Experiment with Casting

It was a...  moderate success.  Definitely learned some things.

So...

I bought some mold making material as well as some pourable two part resin from the local Michaels arts and crafts store.  The stuff is manufactured by Alumilite.

Alumilite "Amazing" line of casting materials.
I built some tech bases as you can see from a previous post and glued a couple onto some thin plastic card.  I did this to make sure no mold material seeped under the base while pouring.

My bases glued to plasticard.
Next I built a little frame out of Legos and stuck my bases into the slots.  I actually knew how large this would be and had cut the plasticard to be the exact correct size.

These legos are literally 30 years old.  I got them from my parent's house.

A perfect fit!
Once my fram was assembled, I mixed up the mold material as directed in the instructions and poured it in.  It's a pretty messy process.  Don't even attempt to use the little tiny cups that come with the kit.  Get some plastic cups or something.  I tried to use the little cups and made a huge mess.

Mold material!
I probably should have made the molds both wider and deeper, but live and learn.  The instructions tell you to wait 2-4 hours before the mold will be ready.  Try more like 8 hours.  It was still kind of gloppy at the 4 hour mark.  I'd suggest just waiting until the next day.

When I was finally satisfied that the mold material had cured, I pulled apart the Legos and pulled out my new molds.  Success!

Molds!
It's hard to tell in the picture, but the one one the left is "sagging" a little.  This is because I didn't make the mold big enough.  I should have made it wider and deeper.  You need to make sure there is enough material to keep the open space the correct shape.  As it is, when I cast bases, there is a little bit of a bump.  Nothing terrible, but the mold warped a little when I tried to take it out at the 4 hour mark.  The one on the right wasn't touched, so it's in much better shape.

Now to mix the resin and pour...

Looks like clear jelly.
I put in a little too much and their's a definite bump sticking out the top of the mold.  This isn't really an issue as I can sand the bases flat later.

The instructions said to let these sit about 20 minutes before demolding.  I waited 3 hours.  Mainly because I was binge watching Zombie flicks on Netflix.  Yup.  I'm exciting.

When I did pull them out, I was met with...

Great success!
Great Success!  A little too much flash, but easily trimmed.   I wouldn't have had any flash if I hadn't overfilled the mold.

All in all, I'm very happy with my results.  The starter kit I bought didn't really have all that much mold making material in it.  I'm going to have to consider what to do next.  Honestly, bases are pretty easy to make by hand unless you're doing a huge army.  They are fantastic "test case" casts though.  I've seem lots of people start with complicated models.  Seriously...  start with a base.  If you can do this right, everything else is doable even if it's a little more complex.

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