Vacforming with clear plastic?

[Sulla]

I've played around with vacuum forming with white styrene in my small-time home made kitchen vac-former, but I'd like to play with clear plastic for an upcoming project. (Here's my vac former with the larger frame http://www.therpf.com/showthread.php?t=53630&page=3. I have a few smaller frames in the works that will fit on this vac-form box.)

What do I need to know about vacforming with clear plastic that is different from vac forming with styrene?
1. What types of clear plastic are good for vac-forming? I am thinking of material no thicker than .125" (about 3mm)
2. Styrene dips twice before it’s ready to form, does clear plastic have the same characteristic?
3. Can clear plastic be 'reformed' with a heat gun for deep pulls like styrene?

Can you think of anything else I need to know that I didn’t ask?

 

[Jumpin Jax]

I form with PETG at .06. It's pretty much the same as styrene, just more rubbery. I haven't noticed a difference in time requirement to heat it, just watch it like a hawk.

 

[00MrNotWrong00]

I form with PETG at .06. It's pretty much the same as styrene, just more rubbery. I haven't noticed a difference in time requirement to heat it, just watch it like a hawk.

What he said thumbsup:thumbsup

Check to see if you can find .040





john

 

[Sean Bradley]

I hear that PETG is really your best bet.

Polycarbonate and Lexan require higher heat, and long pre-drying cycles to remove absorbed moisture. Otherwise the moisture boils when you heat the plastic forcing tiny air bubbles throughout.

I've also seen ordinary hardware store acrylic sheet vacuum formed, but I can't say whether it's better or worse than PETG.

 

[JtotheP]

PETG is what I used for my Viper helmet lenses. You got to be real careful if you want to go back in it with a heat gun.

I've heard that stretching felt over your form will give the best clear effect. Sometimes with clear--you lose some of the transparent qualities from pressing up against a form. Keep your form as smooth as possible (up to 2,000 grit wetsanded). Gel coat is the best tooling surface for your form if you don't try the felt.

Some plastics may have bubbles in it after you V-form them because they began with moisture trapped in it, like lexan usually does. You'll have to bake it first to evaporate the moisture.

 

[Sulla]

Thanks everyone. Great advice.

 

[JoeSoMD]

Related question... we are vacuum forming large (6 foot long x 3 foot wide x 1 foot deep) protective covers from PETG for electronic consoles. They are too brittle for our liking. Anybody have experience with this? Is PETG typically brittle? Any alternative materials? Thanks in advance.

 

[robstyle]

Related question... we are vacuum forming large (6 foot long x 3 foot wide x 1 foot deep) protective covers from PETG for electronic consoles. They are too brittle for our liking. Anybody have experience with this? Is PETG typically brittle? Any alternative materials? Thanks in advance.

Whats the thickness of the sheet youre using? Sounds like it could be the thickness of the formed material once pulled. Some years ago we were testing various clear materials for vac forming with not much success as it had to be extremely durable. The end result was a plastic so thick it negated most detail of the parts it covered as well as the details and shape of the vac pulled part itself.

What about a clear vinyl? I dont know your end result, use or longevity but if its for a prop, clear vinyl may be the ticket.It can be layed out by hand and heated by hand to fit.

 

[Gixxerfool]

Whats the thickness of the sheet youre using? Sounds like it could be the thickness of the formed material once pulled. Some years ago we were testing various clear materials for vac forming with not much success as it had to be extremely durable. The end result was a plastic so thick it negated most detail of the parts it covered as well as the details and shape of the vac pulled part itself.

What about a clear vinyl? I dont know your end result, use or longevity but if its for a prop, clear vinyl may be the ticket.It can be layed out by hand and heated by hand to fit.

Maybe I've misread but I think he said 1 foot deep. That surely can't be right.

 

[made007]

I ordered a batch of petg sheet, pulled a perfect clear visor, then weeks later i went to use the other sheets for more visors usimg the same process and bubbles appeared when heating it, i didnt knew why that happened or how i can fix it, i dont remember if i preheated the first time

 

[zorg]

from what i understand, this could be water in the plastic. or it certainly sound like it.

i think some folk pre bake their plastic to get rid of it, not sure how badly petg gets affected by this.

i have had no issues myself, even though the plastic has been kept in a high humidity environment.

 

[andy19422]

I use clear HIPS, never had any problems.