How to make lexan fit with the contours of a grill
 

How do we make lexan fit the contours of the grill? How can we assure that it will fit nicely?

Hi,

If I were to do it, I'd make template with paper or cardboard that fit as close as possible to the optimal shape. Then cut the lexan according to that template. If that's what you were asking.

Hope that helped.

If you're looking for curved pieces, lexan can be heated and bent, shaped and stretched easily. You've got to heat it to around 200F with a heat gun, or for small pieces you can put them into a wood frame and put them in the oven to soften them up.

In heat-forming polycarbonate, you often get internal bubbles, spoiling the appearance. These are steam. To avoid them, soak the stuff at 200 F for up to 8 hours if it has been stored under high humidity. Then you can ramp it up to forming temperature.

I just flexed mine and tied it down in the corners. If I remove it, it springs back to (nearly) flat again. I'm not sure how flat or curved your grille is, though. Mine's pretty flat, with maybe 10% total curve across the width.

I built Rear Wheel Skirts, and Partial grill blocks with Lexan (polycarbonate). I used a metal bending break, and just bent it like it was a sheet of aluminum. It worked perfect.
Cold bending Lexan (IMHO) is much better than using heat. Heating it is hard to get the temperature even and in the narrow range that allows permanent bending, without bubbling or melting.

Polycarbonate (AKA Lexan) absorbs quite a lot of water. To avoid bubbling when heat forming, soak it at a temperature close to boiling for up to eight hours to dry it before going up to forming temperature.

To get even heating, shielding radiant sources helps, but a fan is wonderful. To do small pieces in a home cooking oven, you can stick a rod through the top vent to turn a temporary air stirrer with a drill, among other possible dodges.

care to elaborate ?
 

doesn't it just break ? if you bend it like that ?

Plexiglass is an acrylic. Easy to cut and bend with heat. I find it to brittle. Even after I was done with my wheel skirts, I started getting cracks. I tried to relieve the stresses by heating, but still they kept cracking and small parts started breaking off.

Lexan is a polycarbonate. Some of the toughest stuff I have ever worked with. It does scratch easier than acrylic, and is much more expensive. It's used in aircraft, and Nascar windscreens. Not as easy to work with, but my Lexan wheel skirts will last the life of my car. Cold bending it with out a metal bending break would be very difficult.
They are both clear plastics, but that's about all they have in common.

I hope that helps a bit

lost in texas
 

Hey
I read your post where did you get the lexan? Did you have your own break or go to sheet metal shop? I live in north texas where is eden?

depending how large the sheets are, put them in your oven (on bak-o-foil) at roughly 180F for half an hour to dry it. It'l bee a little softer as you pull it out, simple offer it up to the area you want and hold it at on end with a clamp then put a 60W lamp near it (3") then leave it to soften and with oven mits push over the con tour you want.

If you can remove the grille and lay it flat so gravity can help even better.

I use Lexan in RC car bodies and the only time I've got bubbling is when I've been doing very focused stuff with intense heat in one area, its best to keep the heat more generalised

Hey TexasCotton,
Sorry, I just saw your question about where to get Lexan. Almost any plastic dealer has a variety of plastics in sheet form. Even Lowe's sells Lexan sheets.
They are very expensive though.
Call around to the larger dealers, and go scrounge for offcuts the right size. Off cuts are harder for the dealers to sell, so sniveling and begging will usually get a discount.
Eden is almost exactly in the dead center of Texas, near San Angelo.

I work for the company, SABIC I-P, who makes Lexan. It used to be owned by GE. Lexan also comes in many different thicknesses. Many are thin enough to form very easily like .2 mils. If you use a laptop, Lexan is used for the film covering a lot of laptop screens. It is very durable even when a thinner sheet material is used.

I know this is a little late in answering this, but I work with lexan and plexi a lot in the window/screen business.
one job, we had to remove 2 side lights in a slider enclosure, and the person had used lexan to replace the glass when it broke from a mower throwing a rock.
anyways, each piece was 12' tall by 18" (1.5') across x .25 thick
I bent one of the sheets over in 1/2 and put my full body weight (170#) on it at the crease, even jumped up and down on it several times, all to no avail.
the stuff is incredibly durable.

Hey, I know a guy who works for Corning who claims the same thing, but that was about glass...
I think that Lexan is now more common than glass, as glass has glare, and is far more complicated to make in that thickness (if you know anything about making plate glass, it's similar, but they do it vertically :eek: ). Lexan it likely more durable with scratching being the only weakness, though it's amazing how flexible standard soda lime glass that thin can be.