Making a lexan windscreen and turtle deck
Has anyone made a windscreen and turtle deck out of lexan? What thickness did you use? Smoked? Did you bend the windscreen cold? Where did you find 5ft wide material for windscreen if you make the long version? I would like to order from kf, but the cost has went up and still I have to purchase my 912. / instruments. Trying to keep cost down and get my bird in the air.
Re: Making a lexan windscreen and turtle deck
I have done three windshields, but have always used the aluminum turtle deck with the lexan windows so no experience there. I have heat formed Lexan for various projects. Lexan can be brake bent in the thickness you will be considering to make a turtle deck.
Originally for the windshield, I think the Speedster used eighth inch, but it was unsuccessful because of the curvature around the wing root. It would craze and ultimately break. I just checked the minimum bend radius in a manufacturer's data page and it is 100 times the thickness. for eighth inch it would be 12 inches - much greater than the two or so inch radius at the wing root. Currently I have the .093" - 3/32" and it is crazing - minimum bend radius 9 inches. When this one needs replacement, I will go to the .060" - 1/16" it will craze as well, but minimally - minimum bend radius 6". which is what I had on my first Model IV.
The issue is, what speeds are you planning on getting out of your Series V. The word at the time was that the increased VNE on the Speedster was a function of the windshield thickness. With my thinner material - .063", I would get some air pressure deformation on occasion when diving near VNE to lose altitude. I never got any deformation when cruising at normal engine settings. I think the speedster went to the .093".
I have always installed it as a cold bend. Some have used a heat gun to release stress at the wing root, but I was always reluctant to do that because Lexan absorbs moisture and if taken to temps above 250° the moisture will form bubbles within the plastic, clouding the clarity. Recommended forming temps exceed 340°. I have no experience with the heat gun, but others claim it works fine. I have tried to vacuum form undried Lexan and it will not only cloud up, but it will result in visible bubbles and distortion on the surface if taken to recommended forming temps. The typical home builder won't have the equipment to bake a sheet of Lexan at 225° for several hours.
I have found no problem cutting a windshield from a 4 ft wide sheet. My current windshield is exactly 46 inches wide at the widest point. You might want to fit your cowl and measure the sweep distance between the door posts to see if a 48" wide sheet would work. I just measured the length of my windshield and it measures about 48" from the turtle deck to the forward edge. I have found that buying part of a sheet is nearly as expensive as a whole sheet. The online site I just checked won't ship a 48X48 inch sheet. It can usually be found locally, though. The local store I use carries Macrolon brand.
Re: Making a lexan windscreen and turtle deck
I would second the 16th inch from local glass shop 98 bucks for 4x8 sheet.more for smoked.bent easily
Re: Making a lexan windscreen and turtle deck
Or you can get the molded plexiglass part directly from Kitfox (manufactured by LP Aeroplastics) and be done with windshields for the lifetime of the plane.
I have one of these on my plane. No crazing, no distortions, no worries of stoving in, either.
Re: Making a lexan windscreen and turtle deck
I agree with Larry, bending lexan at the wing root caused crazing on mine. The extra money would be worth it in my view.
Dan G.
Re: Making a lexan windscreen and turtle deck
At three times the weight and ten times the $$$ for acrylic, it remains Lexan for me. I got 900 hours out of the original with one replacement on my first Model IV.
Re: Making a lexan windscreen and turtle deck
I made my windshield out of .120" lexan. It worked out great. Heated it with a heat gun. It can be done but you have to be careful and take your time. I practiced heating some lexan and bending it to get a feel for what it was going to take. I had cut it to shape using the old windshield as a pattern, leaving a little to trim around the edges for a fudge factor. I fastened it to the top of the plane and then started working the curvatures for the front of the windsheild.
Re: Making a lexan windscreen and turtle deck
Thanks guys! Off to buy lexan tomorrow. It is a shame is not .030, I have over 100 sheets 4x8 that I use to vacuum form r/c car's bodies from. Got my cabin vents in from kf today, got a little glass work to finish. Not that I have enough to do, I pulled my RV6A down today for its annual, not to fly, just work. I built a n11 last year but have not flown off its hours,so I can fly it out of Burbank airport.
Re: Making a lexan windscreen and turtle deck
P.s. did you use the same thickness for your door windows?
Re: Making a lexan windscreen and turtle deck
I damaged my Lexan windshield a couple of weeks ago and did my research to find a replacement. I went to a couple of websites and found some very good place with good prices that I could order from but the shipping was several times the price of the Lexan. Lowes could order it but only if I ordered a minimum of 3 48"x96" sheets. I talked to a nearby plastics company but they didn't seem interested in helping me. I called Home Depot just to check if they might have a sheet in stock. They didn't but a very helpful person suggested I call a local glass company which I did. Brad with Rice Glass in Carboro, NC said to give him a few minutes and let him check. He called back about 10 minutes with good news. He could get the standard Lexan (3/32") or an "aviation quality" Lexan with, supposedly better quality. I went with the aviation type even though the regular Lexan works just fine. The prices were good and no shipping charges. I bought a full sheet even though they would have sold me a half sheet. They even cut it in half for me to be easier for me to transport at no charge. I picked it up yesterday. I went with the LP acrylic the 1st time around. It was a horror story, too painful for me to go into again. I'd advise anyone to run from it. Lexan is light and super easy to work with and much more reasonably prices. Acrylic doors are great but the windshields problem area is around the front wing spar, ready to split at the slightest pressure. Some have done ok with the but I've heard other horror stories like mine. Sorta like working with nitro, one little slip, all gone. James Thomas