Online Community of Zenith Builders and Flyers
Hi Ed! As I recall, I used a thin abrasive cutting disc on my 4" cut-off tool. Placed masking tape over the Lexan, marked the cut line, and just free-handed it. I then took a straight piece of 1" x 2" x 18" lumber covered with a fairly coarse grit sandpaper to straighten-up the edge. I then used a long file to smooth and straighten the cut further.
Use one of the pre-cut edges for the rear of the window - that edge is exposed and needs to be absolutely perfect! Don't obsess too much on your cuts for the lateral and front edges - they're covered-up by the top skin between the wing and the window! and by the windshield LOL!
Sorry to be late in responding, but I ended up with my yearly visit from my sister-in-law, mother-in-law, children, grandchildren, and assorted dogs! Not much time for e-mail or airplane. Did get it all moved to the hangar.
I used a very fine saw to do my lexan and it worked very well. I wasn't smart enough to use one of the factory edges for the back, but it came out well.
I left the side skins of the top window alone. Let them extend over (into & under the root skin) because I figured in a heavy rain parked out side it would keep the cockpit drier.
I did trim my top window sides flush with the sills, but I used butyl caulking tape (about 1/8" thick as I recall) as a sealant along the top of the cabin frame tube and some thinner tape (1/16 or 3/32?) over the gusset and rivets at the rear. It really works beautifully along the cabin frame tube - when you rivet down the window, it squeezes out just about right to fill the little voids running alongside the tube created by the inside and outside flanges of the door sill. The thicker tape on the cabin frame helps even-out the "step-down" of the window from the gusset to the tubing. I also ran it across the rear of the window where it is bolted-in. Gives a nice, water-proof and draft-proof seal!
By the way, the EAA Videos have a good demonstration of using butyl caulking tape.
I had foreseen that problem and ordered some of the same tape that I used when I rebuilt my Ercoupe project. It makes a very nice seal.
Thanks, Bob, I kind of figured that would work. And thanks again for the POH and checklist!
How dry is the cockpit on the 750? Never bothered to ask but is there any place it would/will likely leak?
John and Bob have given some great advice. I think leaving the edges a bit longer on the sides is a great idea. And the sealing tape is well worth the effort.
By the way, Ed, Spruce has some rubber edging/gap seal that looks just like the Zenith windshield seal, only half as wide. I found it perfect to seal the top skin against the Lexan window. I also used it as a gap seal on the underside of the wing between the wing and fuselage.
Thanks, John, will take a look!
I'm a little late to join the discussion, however, I'd like to pass along that after playing around with a couple of test pieces I cut mine out on a 12" throat craftsman bandsaw with about 6 teeth per inch (basically a woodcutting blade) This is nothing like the ACRYLIC windshield. You can't hurt this stuff. Furthermore, I cut two pieces to about 2" long by .5" wide. I then riveted them together near one end. I bent one piece back as far as I could with pliers and then switched to holding it in a bench vice. I couldn't tear them apart. I finally stopped trying after I had bent the piece back 180°. The bend radius was about1/4" so don't worry about cracking it. You can't.........Geoff
Thanks for the feedback. I haven't started on the windshield, but I've heard horror stories, any ideas?