Liquid plastic casting

[spcglider@aol.com]

Originally posted by philippes@Jan 31 2006, 01:29 PM
I live in the Washington, DC area (Smooth-On is in Pennsylvania). I order on Monday and get my products on Tuesday or Wednesday. It's the fastest service I've ever had. Well, them and ULine (www.uline.com) for purchasing shipping boxes.

Be careful with Smooth-On Crystal Clear. I'm sensitized to it and get a violent skin rash if I touch it. I cover my skin and use a respirator when employing this material. (It's generally recommended that you do this with all urethanes.)

Phil

[snapback]1172529[/snapback]​

Of all the urethanes, CLEAR urethanes are the most toxic. They kick out massive amounts of isocyanate gas when they cure. WATER CLEAR urethanes will kick your butt faster than you can imagine.

I still have memories of my boss looking for all the world like Quasimodo after a particular giant tooth-brush molding project his reaction was so severe. His face literally puffed up like a popover.
It took him over a week to get back to normal. But he can't even be in the building when we cast urethanes now, he's THAT sensitive. He'll end up coughing up a lung if he stays.

I personally know three guys who went to the hospital when they were trying to rotocast a 3 foot tall CLEAR Coke bottle. They had a heated rotocasting room to help it kick off, but they didn't vent the space to the outdoors so all that fume-age ended up in their shop. They all pretty much just passed out and had to be ambulanced to the hospital. It wasn't pretty. They failed the job and didn't get paid in the end.

Like I said earlier, I'll be gratified to horrify you further if you care to know the tales. I got plenty.

-Gordon

 

[Neon Sentry]

How would these materials fare for a prop that's actually supposed to be plastic, like a replica toy? Would they be able to handle abuse like regular injection-molded plastic, or would they be far too brittle to be handled normally?

Most importantly, though, would it have the final appearance of an actual, mass-produced plastic item?