lml@lancaironline.net Mailing List Archive

<x-flowed> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Personal replies to Sky2high@aol.com My LNC2 glass was triple primed with WLS and wet sanded (100, 220, 320). This was not hard because good results require work. It does take time if you are willing to use long boards and do it by hand (heavens!). Some of the parts were primed in 1992, some in 1995. The plane was flown in 1996 and 1997 in the primer with numbers painted on with Krylon. After cleaning with acetone, it was painted with PPG and BASF paints and clear coated. Remember that Saf-T-Poxy II was used to construct this airplane. Comments follow: 1. This airplane looks sharp in the sun and has won several awards at Oshkosh and Sun-n-fun. 2. Krylon can be cleaned off with acetone, but there was an apparent bulge under the final finish for one year where the Krylon was used for the N-number. It has all but disappeared. 3. In the hangar, under flourescent light, one can see the weave of the glass fabric. Perhaps I should have had the painter put a final coat of an appropriate primer on before the paint. 4. Certain structures, such as the foam blocks used for the rudder hinge, can be seen as bulges from an acute angle. 5. The 3-M structural adhesive has shrunk and is most noticable at the joint between the wing and wing tip. 6. Pre-preg does shrink and move over time. 7. Those areas where micro was used to fill low spots are as smooth as glass (no pun intended). 8. The prop hole area on the spinner and an area above a cylinder on the cowl have exhibited surface cracks which may be a result of flex and/or heat. The clear coat may have needed a little more flex agent. Note: the softness of the clear coat is perfect since it is shiny with no waxing required. If the surface starts to look dowdy, just re-buff it. 9. Where I have chipped the paint (around a few screw holes, at an edge, etc.) it just looks as though I didn't prep well enough. I.e. the paint chipped off of the primer -- see # 3 above. A strategy for the all carbon Legacy: The carbon fiber is different than pre-preg or glass in that the weave is a lot looser. I expect more pin holes. The moldings are beautiful and less shaping and filling will be required. The elevator and rudder are constructed in such a way as to make the surfaces concave. These will be filled with SuperFil, a two part micro-like very-light sandable filler. This stuff requires muscles to mix, goes on like frosting, is easily tooled and sandable the next day. Prior to priming, I will apply a slurry of very wet micro (Jeffco epoxy) and "final draft shape" the result. This should fill most every pinhole and I hope to see results as in #7 above. I have used this procedure on the Legacy horizontal stab and elevator. We shall see. This is not a unique idea -- A friend with a plans built Cozy applied 2 coats of epoxy (West Systems?) before priming and there is no weave apparent in his finish. While I have not seen any cracks in his finish, I believe that epoxy alone is too brittle for an under-surface. I will then use WLS primer, maybe only two coats, or whatever the final paint person suggests. I also expect that carbon will not shrink or move as time goes on. Any ideas from those all carbon IV's? Scott Krueger LNC2 - N92EX Legacy #2 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> </x-flowed>