Molding plastic clear headlight lens.. somebody help?

[vipcelsior]

I'm attempting a retrofit project where i will be combining the headlight housing of a 1st Gen LS4oo, and projectors from either a BMW X5 / 5 series, of infiniti Q45. The 1st Gen LS4oo headlights just were not meant to house HID's, and that was apparent when I first installed my Phillips ballasts and Phillipse 4700k bulbs. I need to mold clear plastic lens for my headlights, fogs, and corners. I was wondering if anybody had any experience in heating and pressing plastic. I was planning on making a mold out of aluminum. I'd heat the plastic piece and press it on the aluminum and hopefully get the shape I want. I'm afraid the plastic will stick, and i'm scared the plastic will distort. I want to be able to see straight through the headlights without any bends or sorts of distortion. Can somebody help me? Especially someone who has made clear lens themselves for headlights?

 

[Lexurious]

Use a silicone release agent. Then it wont stick. What about using smaller lenses like on the new range rovers or wrx's in a black housing, could look good.

 

[autocol]

depending on what plastic you're using, you could do a variation on vacuum forming - gravity forming!

if you touch the surface of the plastic at all while it's hot enough to shape, you'll mark the surface and you won't be able to get it out. and it will send your light beam all over the place, which is presumably not what you want if you're upgrading to better lights!

i would make the final shape i wanted out of some heat resistant material, coat it in a release agent as suggested, and then use gravity to drape the plastic over the buck in an oven or something...

not a small task.

 

[vipcelsior]

i'll be trying gravity forming. I was thinking of heating the plastic over an aluminum mold. I will try the silicone release agent so hopefully it wont stick. kinda like baking and adding a little spam? haha. Would i be able to use a fiberglass mold? Would fiberglass be able to stand the heat? Fiberglass sounds like a really good idea because i could get the plastic exactly like the stock form. I'll be starting this project this weekend, so i'd like to thank you all for the great input.

 

[Zuffen]

Fibreglass will melt and catch fire if you heat it enough.

Have you thought of using plater of Paris? I its cheap fairly heat resistant (it may crack but not burn.

I would suggest spray the inside of your headlight lens with cooking spray. mix the plaster and fill the mould you have created. Once dry (allow 12 hours) you can pull your plaster mould out and paint it in heat resistant engine enamel.

You will need to decide what the best parting (non-stick) product is then try it all in the oven. I would think cooking spray would be ok but it may damage the perspex when it's hot.

One option is to use a larger piece of perspex so you can assist gravity by applying hand presure outside the lens area.

Keep us posted how it goes.