I've been experimenting with thermal vacuum forming and thought I'd ask for advice on a problem I can't solve. Below is a Porsche 906 window mold. I am forming 1/8" "plexiglass" (I've tried acrylic of differing varieties). I'll use Lexan once the problem is solved. I have tried a felt covering and a flannel covering, but each time the subtle texture of the covering transfer to the pliable plastic. I'm heating to 300F, which is barely hot enough to allow the vacuum to pull the vent window and helmet bubble in. I have a mold for a Porsche 907 window and it's covered with something like suede. No successful pulls on that one.
So far, the windows all seem to end up with a texture-blurred middle at the height of the mold crown while the edges are clear.
Each attempt is $25 worth of wasted plastic. Anyone form plastic windows with success? I'm tired of wasting time and money.
I've never worked with stuff this way, but is it possible to remove the texture by buffing it out? Seems to work for headlight buckets.
Would a vinyl/fake leather covering work? I have never worked with this, but sounds like you need something flat without texture and vinyl might work. And trying buffing it too.
Yep you're gonna get texture every time as long as there's a texture to pick up. Either buff it out or try a smooth covering.
Fun what it does to your vacuum cleaner, isn't it? I lit my first one on fire.
I've done it. The molded material invariably picks up the surface of the mold. SO you need the mold to be polished smooth for a smooth product.
Same problem with your bag, any creases there will transfer to the window piece you're making.
You can pull into the corners a little better with tiny air holes drilled into the mold. Those holes will transfer to the plastic, but they will be in an area that they likely won't cause any problems.
You might want to experiment a little with temperature. Plastic goes much softer with just a little more heat. But you can scorch it too. It's been some years since i was doing plastic molding at home (making motorcycle parts), but as I recall I found 325 to work better.
You also may want to look into drape-forming...I remember reading about a guy doing this to make a Lexan windshield for an old McLaren race car replica.
The guys who are designing the Goblin (based on a Chev Cobalt donor) have done it for their windshields in this thread. Maybe PM them for advice or ask them to contribute here?
