Bending Polycarbonite?

[BoonDockSaint]

HI!

Not sure if this is the place to ask, if not please redirect me.

I make my own windshields for my bike out of lexan. These are for a harley with a fairing, the shields are about 10" high by 24 more or less. the new fairings are much more sharply curved so If I just tighten it in there,(like the old ones) it cracks within a few months.

I was thinking of heating it up and then installing it. All I have right now is a standard heat gun. I DO have an original windshield from the bike, if I heated the lexan on top of the other windshield would they stick? Is there something I could put between them? Better ideas? I need to have the lexan curve, not bend and I don't have alot to experiment with right now.

Any ideas or experience?

Thanks!

 

[racingtadpole]

If you heat it over the old one, it will be too big. You need to make one using the inside of the original for dimensions (stop if from deforming again when the heat is applied by cutting some timber supports and fixing it to it) and then take your new screen from your mould (similar to how you fibreglass). You shouldnt have any cohesion issues, but you may want to put a piece of butchers paper between the two to protect the surface, watch out for it bunching and setting your curves/bends away from original.

This may help you further:

http://bbs.homeshopmachinist.net/threads/30224-How-do-you-bend-Lexan-or-polycarbonate

 

[ilovevocs]

I have bent it in my leaf break. Just go slow, few degrees at a time.

 

[BoonDockSaint]

If you heat it over the old one, it will be too big. You need to make one using the inside of the original for dimensions

This may help you further:

http://bbs.homeshopmachinist.net/threads/30224-How-do-you-bend-Lexan-or-polycarbonate

Very good point, thanks! I don't fabricate too much stuff. That link explained it well enough.

 

[TauntDevil]

Another thing is, if possible, and I know without one of the expensive machines, that it is very difficult. But if possible, try heating the entire piece and evenly to reduce the amount of warp. Did the windows on one of my track cars not too long and it wasnt very smooth despite me moving the heat gun the whole time and not stopping in one spot.

Not sure if you plan on making a lot of them but if so, I would see about getting a oven if it would fit or if you know a fab person, have them modify one to work (What we did for out Powder coat stuff).
Hope this helps. Best of luck!

 

[bczygan]

I've bent windshields 90 degrees for an aircraft an one corner, flattening out to 45 degrees at the other end of the bend. Using a HF break and firm and repeated pressures.

Made another 1/2" 90 degree radius with a bunch of small spaced parallel bends about 1/8" apart.

No heat used.

Thickness is important. I think it was 060 and 040.

Bill

 

[FMC]

you sure its lexan and not acrylic? lexan is polycarbonate and shouldn't crack

 

[Strouty]

I was thinking that too, we used lexan on skateboard ramps because it would not crack. It was sure slippery though.

 

[TauntDevil]

Well Acrylic and Polycarbonate are both lexan. The difference is the material. Acrylic can barely bend and from what the first post states is that it is formed correctly with pressure but with time, starts to crack. Doesnt sound like acrylic to begin with unless it is super thin.

 

[mmack66]

Well Acrylic and Polycarbonate are both lexan. The difference is the material. Acrylic can barely bend and from what the first post states is that it is formed correctly with pressure but with time, starts to crack. Doesnt sound like acrylic to begin with unless it is super thin.

Acrylic is not Lexan.

 

[FMC]

lexan is a trademark name for polycarbonate, like plexi glass is a trademark name for acrylic

 

[wasfast]

There's a color difference between acrylic and polycarbonate. Looking at the edges, acrylic has a slightly yellow appearance, polycarbonate has a slightly blue appearance.

 

[wingnut_1]

Acrylic is not Lexan.

lexan is a trademark name for polycarbonate, like plexi glass is a trademark name for acrylic

Both of these posts are correct

 

[FMC]

you can also cut polycarbonate with tin snips

 

[laser3kw]

I have bent many parts made from polycarbonate in a sheet metal brake. Just swing it at a slower rate. Leave the protective paper on it until complete.