Lexan is polycarbonate sheet, which is a little more difficult to work than
acrylic sheet such as plexi or acrylite. Either can be heated and bent to a
radius. They will scorch and bubble if overheated.
Years back, when I was working with plastics, we usually worked with acrylic
and were familiar and comfortable working with it, as well as with styrene.
We weren't as familiar with polycarbonate, and it didn't work well under our
usual acrylic techniques. In particular, I remember polycarbonate having a
greater tendency to burn while cutting, and clog the blades, and it being
impossible to score and snap. I seem to recall it was difficult to flame
polish also. Maybe thermoforming is easier? which of course is what the OP
wanted to do, but I don't recall.
The polycarbonate is a bit easier to work if you're not used to plastics. Is
won't crack when cutting. As a matter of fact, you can cut it in a sheet
metal shear. It hot forms well and can be cold formed too.
My limited experience is with making a small box for an aquarium from
acryllic, not sure it it was Lexan. Aquariums are built from many plastic
materials, not sure about Lexan.
I expect Lexan is able to be molded with heat. You need to control the
heat. I used a heat gun which is an electric heater element with a fan to
blow the hot air. The challenge will be getting the same heat across the
material so that it molds consistently.
Too much heat and you will see bubbles before scorching. Using a propane
torch is likely to be too high a temperature and could scorch or melt the
You could try making a plywood mold, laying the Lexan over the mold and then
gently applying the heat gun until the Lexan starts to drop into/over the
mold as the temperature reaches the point where the Lexan is flexible.
Tight radius is possible, but will take practice.
Practical? Not so easy.
You can build a "mold" or mandrill to wrap the softened plastic once heated.
I'm not sure, but polycarbonate softens at about 270 degrees. If the sheet
fits in your oven, you could heat it, shape it, then let it cool in place.
If you use a heated mandrill, it'll bite you.
Avoid Lexan / polycarbonate and stick with acrylic / Lucite / Plexiglass
/ Perspex. Much easier to work with - or rather not "easier", but much
more likely to be successful.
On Sat, 22 Jul 2006 21:32:13 -0400, firstname.lastname@example.org wrote:
Lexan must be baked at a low temp. befor raising the temp
enough to bend it. Try 150 to 200 degrees for 12 hrs on a test
piece. The reason is that Lexon has a lot of water in it that
must be driven off at a low temp. That is the same reason
that oil or gasoline make Laxan brittle. They replace the
water. Plexi doesn't have this problem.
You 'll want to make a mold against wich you'll press the heated lexan
The process doesn't require any extraordinary skills, as long as you
heat it over a large surface.
If you make many of those curved doors, you could build a heater for
that at very little cost - something similar to the heating element
used in this DIY vacuforming table http://www.tk560.com/vactable4.html
Using a hot air gun for a large surface won't be very good, but it's
Depending on size, you might want someone to help you hold the lexan
sheet / press it onto the mold. Another usefull thing is to screw two
1/1" pieces of wood on the long edges, that would help you get an even
pull on the sides (you'll leave that sheet bigger anyway - trim it
after it's been formed).
I hope I've made myself clear, even though english is not my native
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