How does thermoplastic work with curved surfaces?

I was thinking about getting some thermo plastic. However, I wasnt sure if it would get creases in it if used over a spherical surface. If theoritically I put some thermoplastic over a bowling ball, would it match the curve of it? Thanks!

-xD

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rickharris7 years ago
I am assuming you want to make a globe roughly the size of a bowling ball?

Using a sphere isn't the way to do it!.

To make a globe you will need to make it in 2 halves. You will need either half a sphere as a pattern OR you can reverse the system and use an open circle as a blow mould.

Clamp it onto the plastic and heat the thermoplastic up to a temperature where it is rubbery and drooping then blow through the circle from underneath forming a perfect half sphere.


I've also seen hemispheres made by slumping through a ring.

Steve
lemonie7 years ago
You could do this right, but it does depend on what you're using and how - what have you got?

L
! xD ! (author)  lemonie7 years ago

Well, Im very unfamiliar with thermoplastic and Ive not bought any yet, but I was thinking about using it to make something similar to scoochamaroo's Creepy Mask instructable, but I wanted to make it a whole helmet type of mask rather than simply a face mask. What do you suggest? 

lemonie ! xD !7 years ago
I'm not very familiar with thermoplastic, but you've got good instruction in that Instructable - ask Sarah?
For masks, I've used paper & PVA - it takes a long time but you can get what you want.

L
! xD ! (author)  lemonie7 years ago
Ive looked at it in that instructable, but I think I might just go with plaster bandages technique like in the Ludo instructable ( https://www.instructables.com/id/Ludo-from-Labyrinth-costume/). Im not familar with the paper and PVA thing, is that like what is used in Horror Head? (https://www.instructables.com/id/Giant-Mask-Horror-Head/) Thanks for your help lemonie, its appriciated!
-xD
Depends on which thermoplastic it is and how you form it. Working with Polymorph/Friendly Plastic is very different from vacuum forming, but both are thermoplastic techniques.