Wednesday, October 8, 2008

Who knew I'd ever get this excited about plastic...

Sorry for posting again so soon, but I just wanted to share - my mold rubber and liquid plastic from arrived on my doorstep this afternoon! Yeah!

I need to buy some modeling clay and start making a box outta foamcore for my little monster dude...

Let the planning, fretting, and stress begin! ;)


phantom42 said...

Some tips..

1) make sure you get the mold release into the crevices. its REALLY hard to get some casts out of the mold.
2) if you're doing multiple casts at once, keep it limited. once you mix that resin, it will start curing instantly. you don't have much time before it's hard and stuck in the cup.
3) for the love of all that is (un)holy, cover your work space with something removable and replaceable. i had to use an orbital sander to get the hardened resin off the work table because emily didn't.
4) keep everything within arms reach
5) measure precisely and pour slowly. air bubbles are your enemy.
6) your first few molds will probably end up in the trash - usually due to improper measurements or trying to rush something. i don't care to remember how pissed off emily used to get about bad molds.

iirc, some of those chemicals have limited shelf lives, so just make extras even if you're all done.

Shelly Rodriguez said...

Whoa, thanks for all the tips!

I remember reading somewhere to pour slowly (like you mentioned) and high? Does this make sense to you?

Would you recommend pouring water in the mold before making a first cast, and then pouring it back out to get a more precise measurement on how much resin to use?

I've been meaning to get a plastic computer chair mat for underneath the craft table... should plastic bags split open be enough to shield my work area from any spills, or should I invest in a tarp of some sort?

I'm pretty sure that Xavi will have to face my wrath this weekend, haha! If I do it with cosplay, of course I'm gonna do it with casting. ;P

phantom42 said...

Pouring slowly, obviously - but high? I don't know how much that would help - it might help create a thinner stream as it pours... Not sure if it'd make much of a difference though.

Yes. Pour water in first to get precise measurements. The set of information that Emily got when she first started instructed her to do that. I just assumed it was part of the instructions that came with the chemicals. Maybe not? But yes. It's technically possible to do a water displacement measurement to figure out how much mold rubber you need to, but Emily never did that - just for the casts themselves.

I'm referring more to throwing a plastic tarp, or crappy sheet of fabric over the work desk/space, but yes - you should definitely have something on the floor in case of spillage/droppage onto the floor. You WILL, however, spill some onto your work desk. That shit is REALLY hard to get off, and since it's basically a lump of plastic, you can't just ignore it like a paint spill.

Shelly Rodriguez said...

I haven't had a chance to open up my boxes yet (I took a photo, grabbed some lunch and left), so they may have instructions.

OK, I'll do that with the mold rubber too--for some reason that didn't occur to me. Hopefully I can get away with using only one of my pint sample sets of rubber, and I can save the other for another sculpt.

I'll be looking on youtube for demo videos, for also has a ton of technique vids, so I'll try looking through those too.

I do remember Emily mentioning that the rubber has a pretty limited shelf life, I'll make sure I use it up within a month or two!

phantom42 said...

Doing the one for the mold is a real pain. I remember Emily doing it once or twice, and it was such a pain that she stopped doing it.

It's tough because you have to build your box and make it super water tight.

In hindsight though (and this is not how Emily did it), I'd suggest building your foam core box and then lining it with saran wrap as best you can. That way you can try to avoid soaking the foam core box.

It's really not critical that you do this for the mold, but you figure, why waste it unnecessarily?

Lenox Knits said...

There is nothing like coming home to supplies on your doorstep!

Shelly Rodriguez said...

Lenox Knits, I agree! Its exciting, especially if they're things you've never gotten to use before! Its like getting a new toy. :)

Steve Talkowski said...

Hey Shelly!

First - I agree with everything Phantom42 said in his first comment.

I would also add that you might want to reconsider using foamcore for the mold walls, depending on how large the figure you're casting is. My first Sketchbot mold used 1/4" foamcore walls and it bowed out. The second round I used plexiglass, and it was much sturdier - and my molds came out perfectly squared off.

Peruse thru my Flickr set and learn from my mistakes ;)

Shelly Rodriguez said...

Hi Steve!

Unfortunately I already started the mold process before I got your comment, and am using the foamcore.

Fortunately, though, it didn't bow out at all, and worked like a charm! I used a little too much rubber, but now I know I can get away with less for next time.

I'm definitely gonna look around your flickr, though--I've been learning so much just by looking at process photos!

Thanks again. :D