lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> I have some suggestions for those of you who are well along on your door, and for those of you who think a $6800 retrofit is not to your liking. We saw cracks in the interior paint on each side of the window frame after the first few flights on our LIV. I removed the door, removed the door seal, sanded the paint down to bare glass, drilled many, many small holes in the inner frame, and injected an epoxy micro mix into the cavity a little at a time until the whole frame cavity was filled with epoxy foam. Warning--take care not to change the curvature of the frame, because the epoxy foam in the framework will really stiffen the curvature, and your door may not seat correctly afterwards. You must inject the epoxy micro foam into the cavity a little at a time, otherwise you will get an enormous heat kick that will boil the foam and deform the components. This is a tedious project, but is well worth the effort. Just keep thinking that you are being paid $6800 for your work.... Once you have the door frame ring cavity filled with foam, start laying up layers of Carbon Fiber on the entire inner surface of the door. Do not use Glass Fiber. I laid up 4-6 layers of Carbon Fiber on the stiffener ring, and 2 layers on the outer edge. I would have preferred to put more layers along the outer edge, but adding thickness here made the door stick out higher than the finished fuselage. Be sure to put lots of Carbon Fiber around the window frame, especially on the left and right sides. This is the weak point of the whole structure. I think this weakness in this area is one of the major reasons that windows have blown out--it is a major area of flexing because of its lack of stiffness and strength. Once you have laid up these added amounts of Carbon Fiber on your door, you will find that you may have to get a stronger gas strut to keep it open. Additionally, you may find that you may want to reinforce the outer door frame with Carbon Fiber as well to compensate for the added weight to the newly reinforced door. We did this, and I am happy that we did. Well, thats my story, and I am sticking to it. The CF reinforcement didn't solve the problem of the door seal pushing the door out into the slip stream, but it sure did solve the flexing problem that had caused cracks on each side of the window frame area. Happy building, David Jones, Pecatonica, Illinois LML website: http://www.olsusa.com/Users/Mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com.