DIY Vacuum Forming
 

Hello -

Christ mentioned a vacuum forming instructable in this thread :

http://ecomodder.com/forum/showthrea...disk-3657.html

I think it is also relevant to this thread :

http://ecomodder.com/forum/showthrea...iscs-7381.html

I Googled and found this :

Vacuum Forming with your Kitchen Oven and Vacuum Cleaner
http://www.youtube.com/watch?v=hGBRiYhxRTM

Here's the dude's website :
Vacuum Former Plans

For smooth racing disks, I am *guessing* that you don't even need the vacuum part, because the wheel cover shape is so uniform and simple. I think the only question is figuring out how thick you want the wheel cover to be.

But, for other things (like a side view mirror delete cover), the vacuum would become a must.

Question: Would I have to worry about "outgassing" (not exactly the right word) as the plastic heats up?

In any case, lotta possibilities here,

CarloSW2

Ya, I'm not sure you'd want to cook your dinner in the same oven you just got through cooking plastic in... :eek:

I could be wrong tho...

You do need a vacuum, or you won't be able to get the warmed sheet to conform to the mold. You'll end up molding all of the air pockets.

Building the vacuum table itself is really easy, especially if you don't need rail guides or anything. You can make one out of 2x4s, pegboard, drywall screws, and caulking compound.
If you're doing it right, you won't be heating the plastic enough for it to be combusting or producing fumes. You're heating it to the level of thermoforming, the same temperatures that the manufacturer uses to injection, blow, or vacuum mold it to the desired shape.

Not if you have the proper temperature for molding. You also want it to be uniform.

Hello -

Thanks for the advice. Since the operative word phrase "if you're doing it right" is in play, I don't think I will try it with our oven. I need room to make mistakes. I would need to find another way to achieve the same thing.

CarloSW2

You may want to try using a heat gun from a hobby or craft store. If I remember correctly, they are fairly cheap, and can produce temperatures near 400 degrees F, which is more than enough to shape acrylic in a vacuum former.

eco86 -

Stop reading my mind, :p ! I have a heat gun from Harbor Freight in the garage. I could place the plastic over the pizza pan (that has a grid of little holes) and "heat" from below. Let the plastic sag over the mold.

Works great in my mind, but reality will tell ...

CarloSW2

Hello -

I have since learned that sign shops use "thermoplastic" to do their vacuum forming. Mayyyyybeeeeee I'll go to a sign shop and get a quote on how much it would cost to do four pizza pan wheel covers!

CarloSW2

Thermoplastic is really any plastic that can be formed through heat. Some of the popular ones are styrene (solid, not like the foam), acrylic, lexan and ABS. I wouldn't recommend styrene, mainly because it cracks easily and I'm not sure how it would hold up to being mounted on a wheel. Acrylic is slightly better, but ABS would probably work the best.
I recommend checking out McMaster-Carr for materials, but only if you live near where their distribution centers are, since the shipping is usually the most expensive part of the bill if you're buying anything larger than a couple square feet.

eco86 -

Thanks for the clarification. I am repeating what I was told, so the detailed definition helps.

CarloSW2