vacuum form polystyrene question

hoang031 · Post by **hoang031** » Fri Nov 14, 2008 10:10 pm

i have a pattern that is 9.5x5x1.5 inches and i bought a sheet of .080 thick 6x12 inch styrene from a local hobby store. can i still use this sheet or is it better to find a bigger sheet since the styrene needs to get deformed

bacteria · Post by **bacteria** » Sat Nov 15, 2008 4:42 am

Bigger sheet, otherwise the plastic will be very thin in places. Ideally, if the height of the mold is 1.5 inches tall, you need min of 1.5 inches clearance each side, so you need a minimum of 12.5 x 8 inches. Minimum - ideally, if you can, about 13-14 x 9-10 inches

It will work, but your 2mm using the board you got, will probably end up about 1/4mm - 1/2mm thick in places otherwise. In saying that, you can reinforce the inside of the case; and also, there will still be reasonable strength even from 1/2mm potentially. Depends on the shape and curves of your case.

Kurt_ · Post by **Kurt_** » Sat Nov 15, 2008 12:52 pm

That's also assuming there's no plastic wasted. It's gotta be held in place by a frame, which will take another 1"-4" away.

skeneegee · Post by **skeneegee** » Sat Nov 15, 2008 1:04 pm

I've never vacuum formed anything, but I have worked with styrene and acrylic sheet.

Does somebody with experience think acrylic would be a good choice for vacuum forming cases?

bacteria · Post by **bacteria** » Sat Nov 15, 2008 3:59 pm

Yes, Kurt_ - I quoted the usable area, you also need the area under the frame, as you indicated correctly.

You can use Styrene - it is the same stuff as Plasticard, which I use - the USA call it Styrene, other countries Plasticard.

Jimmyg1995 · Post by **Jimmyg1995** » Sat Nov 15, 2008 4:56 pm

bacteria wrote:Yes, Kurt_ - I quoted the usable area, you also need the area under the frame, as you indicated correctly.

You can use Styrene - it is the same stuff as Plasticard, which I use - the USA call it Styrene, other countries Plasticard.

Why is usa always different?

bacteria · Post by **bacteria** » Sat Nov 15, 2008 5:10 pm

I thought it was the other way around; the UK is an island after all!

Kurt_ · Post by **Kurt_** » Sun Nov 16, 2008 2:08 pm

Well we all are, technically.

I do believe vacuum forming acrylic is okay, it's a little tougher to do than styrene, though. Melts at a higher temperature, sags less i think, etc etc.

hoang031 · Post by **hoang031** » Sun Nov 16, 2008 2:23 pm

Just tried it and works fine. Had to reheat the styrene 3x since the first 2 times produced crappy forms.