As some of you might recall I posted a request on how to "cutdown" a windshield back in September for my 67 Spitfire. After looking at multiple options, i.e., sandblasting, waterjetting and scoring the windshield, I've decided (well it was decided for me) that lexan is probably going to be my best option. The waterjet and sandblasting folks don't want these small projects and the glass folks don't want to try the traditional scoring the glass and lighting it with alcohol. I've read that lexan has issues with scratching and yellowing but it is not a brittle as plexiglass. Some folks say it can also be easily polished.
So, I'm thinking a 48" x 7" piece of lexan should be easy to moulded to fit into the windscreen frame without any major issues. I plan on using machine screws to secure it to the frame.
Any other comments, drawbacks or experience with using lexan?
Shaun
HalfDork
12/5/11 2:47 p.m.
In my experience Lexan is fairly forgiving if you cut or drill slowly at fairly high speed with . making a flat pattern that will fit, once deformed to a shape that is far from a plane, is not simple without a CAD program that makes flats from complex surface. Trying to cut as you go could be a nightmare. Starting with thinish polypropylene sheet to get a pattern might work, but off the cuff that does not sound like fun.
Could you make a mold from the inside of the original and lay hot Lexan on it?
These guys do good work and might be able to help you.
http://www.glapinc.com/Corporate/solutions.htm
mw
HalfDork
12/5/11 3:30 p.m.
As long as you only have curvature in one direction and a decent frame to hold it in place it should be fairly straight forward.
If it's not a compound curve you can probably just screw/rivet the lexan in the frame and call it a day. Tight/compound curves might take some heat. Lexan takes something over 300 degrees. There's an interesting thread on pelican that leads to a canopy site... lots of info about making a molding oven on a GRMish budget.
linky
Keith
SuperDork
12/5/11 3:39 p.m.
Shaun wrote:
In my experience Lexan is fairly forgiving if you cut or drill slowly at fairly high speed with . making a flat pattern that will fit, once deformed to a shape that is far from a plane, is not simple without a CAD program that makes flats from complex surface. Trying to cut as you go could be a nightmare. Starting with thinish polypropylene sheet to get a pattern might work, but off the cuff that does not sound like fun.
Buy some brown wrapping paper from the post office. Works a treat.
Thanks for the good input. I checked out the glainc website and see they do windscreens for race vehicles. I'll contact them and see what kind of response I get, providing they aren't too expensive.
In reply to triumphcorvair:
You can use me as a reference if you wish. Their shop is in Flint, my family has written their insurance for many years and I have bought parts from them. Send me a message if you want more details.
pilotbraden wrote:
In reply to triumphcorvair:
You can use me as a reference if you wish. Their shop is in Flint, my family has written their insurance for many years and I have bought parts from them. Send me a message if you want more details.
Ok, Many thanks for you help!