Vacuum forming Lexan?

[ToplessZ]

What about lucite. I saw this at lowes the other day and bought a small square for the heck of it. It is pretty scratch resistant and cheap. I had to really throw it around to get it to crack too. I wonder what the molding temp for it is. Also Im a little worried would extended headlight use especially h4 bulbs make enough heat to warp your headlight cover.

[ToplessZ]

Bump on the lucite any input on it instead of lexan or plexi check it out at your local Lowes it looks promising.

[Guest Aaron]

All I can tell you about lucite is that I had a lot of trouble cutting it without cracking it. It also can make a nasty gash on your finger if you get mad enough to throw it across the yard.

[blueovalz]

Makes me wonder if it would withstand a rock ding at speed without cracking, especially in cold climates.

[ToplessZ]

Id say it would hold up to a rock ding I throwing it around and beating on it the other day seemed pretty solid slightly less flex than plexiglass. When you cut it I believe you have to leave the backing on both sides and use a very fine tooth blade. Id like to see how it forms anyhow

[SpeedRacer]

I think you will find that Lucite is way to brittle to use for headlight covers. Lexan is a much better choice and is used by all the race cars that have covered headlights.

 

BTW, Lexan is used by banks because, when it's thick enough, it is bullet proof.

[staledale]

If I remember right RacerX had a post on this awhile back. But he wasn't into the vacuum forming.

[Tony D]

260DET, that is exactly how I made the rear window for my Fairlady Z racer while I was in Japan. Did the 1/4 windows and Roll-Up door windows, too.

I never got spunky enough to try it with the windshield, though.

The relatively easy shapes of all these galsses lends it'self to the "heat and drape" method.

 

I heated mine on an Asbestos Board (cough, cough...), inside a sheetmetal enclosure that had diffusers on it, and six heat guns blowing in under the asbestos sheet...

I scabbed an oven thermostat to a relay to turn the power strip on and off to control the heat guns (which were set for "high" which I believe was 1100 degrees...) I agree, the key is even heat that final setup was NOT what I started with, and I'm sure the first few windows had severely degraded stregnth from being heated several times to get the sheet evenly heated. In the end I held the temps at 250 for 10 minutes, then turned it up to 350. When I could see the temp gauge (oven thermometer) over the center of the sheet read 370 I would shut the works down, wait until the temp dropped to 350, and pick it up gingerly with tongs and place it on the window next to the "furnace".

 

Now all me secrets are revealed...

 

I never tried the cvacuum forming, but I would think the complex curve, and depth of the item would require some sort of pressure differential device or an A-B mould type setup.

 

Harbor freight is selling heat guns for $19 (and below $10 on sale!) so I might try this setup here in the states just for some fun.

McMaster Carr has Lexan in a thickness very close to the Stock Glass, so it goes into the stock rubbers without leaking if you trim it closely to the original. Very Nice, especially if you get the 90% light blocking tinted stuff!

[dot]

Hey Tony:

Thanks for the experienced view. I thought one could get away with a single heat gun and hadn’t realized so much controlled heat would be involved.

This pic is interesting.

[Tony D]

You probably could get by with a very low-volume furnace setup and one heat gun, but I would think the heat source would have to pe piped into the center of the setup, and then diffused around the outer peripherey.

It would just take longer to heat it all up.

With a multiple setup you can heat the first window in less than 20 minutes, and subsequent sheets at intervals of about 10 to 15 minutes.

 

The only problem I had was the Asbestos board sometimes leftfibers on the surface, or transferred some of it's texture to the composite being heated. I usually polished it out using common techniques.

 

For something like the quarter windows, one gun is more than enough. I used two on the side windows, and four on the back glass, though I suspect I could have gotten by with two.

 

Once the bricks and concrete of thefloor are up to temp, it makes it all happen much quicker.

[ToplessZ]

ok so youve got me thinking...how many alternative methods would there be to forming a part such as that hood. if you were to make a clay mold of the hood and form the lexan via large oven would that work. I thought about building an oven for powdercoating and this would definatly expand its uses.

[dot]

When I built my hood out a fiberglas I used the original hood as a mold. By removing the metal brace underneath and making a wood form to support the metal panel. Resin and glass were layered inside the open panel. This could work for Lexan. Place the plastic in the hood panel and add heat or so the theory goes. As for the practicality of a clear hood…if the wind didn’t break it I think the engine heat would deform or degrade it somehow. But don't let that stop you from thinking Jared.