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Polycarbonate,, PETG, or Plexiglas by cmechmann
Started on: 07-10-2015 11:05 PM
Replies: 0 (93 views)
Last post by: cmechmann on 07-10-2015 11:05 PM
Posts: 973
From: Baltimore Md.
Registered: Dec 2012

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Report this Post07-10-2015 11:05 PM Click Here to See the Profile for cmechmannClick Here to Email cmechmannSend a Private Message to cmechmannEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sorry I just don't like my pop up lights.
On my 85 I had raided an old Q45 at a pick and pull for the projectors. I had made a set of forms. Made brackets and installed them.
They were kind of like the ones I see offered here but mine set back further so the bump didn't have to be as high. The vacuum forming came out decent.
A combination of hot sunny days and the heat from the projectors were causing the PETG/VIVAC to distort. The metal projector housing were around a 1/2 away from the cover. I reinstalled the OE paddles and lights.
I was using .090 or somewhere close to that. You could beat them with a hammer and they would not break but they start to get soft at around 220f The vacuum form temp I was using was around 270-280.

This time I bought a real set of Hella 60mm low beam and a set of EOE 60mm for high beam. The EOE are Bi halogen, but I removed the shutter to used them just for high beams. The Hellas are DOT/SAE VOL approved. Both sets can get wet. They are sealed. The EOE shutter wires came in at the bottom through a small hole between the lense housing and the reflector in a grommet.
Due to them being 60mm I was able to mount them back and high enough not to have a bubble in the covers. Found a "sweet spot" that allows them to have a good light pattern and still be under a near flat cover. I won't be able to use HID conversion, but I don't want them anyway. Using the OE bracket for the paddles/covers, I made a set of small brackets that bolt on. Using some "plastic granite" (kitchen cutting board that you can set hot pans on) made faces to hold the projectors that the other brackets bolt to. I put them in tonight and I was able to get the pattern of light about 10-12 feet in front of the car. The Hella projectors have a very distinct cut off. I still have some aiming to do but that was with the low beams just under the top edge of the deck lid of the car in front of me. Not bad for flush mount. If this all works out I will take pics. There is no changes to the car and all the stock stuff can be put back in. I made even the wiring plug and play. No drilling or cutting of the car.

OK for the problem. I will need to make a mild curve to match the curve of the original paddle/covers.
Lexan/polycarbonate is not UV friendly. scratches easy. But with .118 1/8" could drop a bowling ball on it and not hurt it.
It doesn't soften until near 270f. But before forming it is recondmended that it is baked to reduce crazing from moisture that it natrually absorbs.
Plexiglas/Acrylic UV resistant, scratch resistant, fair temp resistance, But brittle. I had formed a set to some success but the heating makes it even more brittle. Using .118
With those I can drape form. Heat a 12x12 sheet in a toaster oven to 270f and drape over the OE cover with non-stick aluminum foil then cut to fit. Imperfections in the form don't really show because it is such a mild curve and those plastics are just softened.
PETG/VIVAC is UV friendly, somewhat scratch resistant and you can beat it with a hammer. But a lower temperature tolerance.
Also when you heat it it gets much much softer and any imperfections in the form show up. To do it right really needs to be vacuum formed. And I might just end up with the distortion problem again.
The trials and failures are getting a little expensive.
Unless I get some good suggestions, I'm most likely going to bake some Lexan, make spares, keep them waxed to help keep them from oxidizing so fast.
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