macleodm3 Posted December 5, 2009 Share Posted December 5, 2009 I bought my featherlite main gear for my Cozy MKIV second hand around a year ago. I don't like the looks of the outer UNI layups which were installed by the previous owner. What do you all think is the mistake made to have so many dry looking areas in this layup.... the entire gear looks like this photo. Quote Andrew Anunson I work underground and I play in the sky... no problem Link to comment Share on other sites More sharing options...
Kent Ashton Posted December 5, 2009 Share Posted December 5, 2009 Looks pretty normal to me. Maybe a touch dry. Nothing to worry about though. Quote -KentCozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold Link to comment Share on other sites More sharing options...
rickh Posted December 5, 2009 Share Posted December 5, 2009 Cool/cold ambient. Plastic film 'lo vac' and excessive squeegeeing (any indication of glaze from the plastic or peel-ply?) 'Fast' hardener and/or working the epoxy during the gel stage. To the blotches disappear after an alcohol wipe? Rick Quote Rick Hall; MK-IV plans #1477; cozy.zggtr.org Build status: 1-7, bits of 8-9, 10, 14 done! Working on engine/prop/avionics. Link to comment Share on other sites More sharing options...
longezdave Posted December 5, 2009 Share Posted December 5, 2009 The photo makes it APPEAR that the layup done by the previous owner fails Rutan's dryness criteria (dryness evidence more than 10% of the area). I'm GUESSING that it won't be a problem in this part of the aircraft, since the layups are primarily to add torsional stiffness. I'm not aware of failures of the gear legs that could be attributable to such a dry layup and believe there is probably workmanship as bad in the field. Sure we have legs that fail by being over-heated or ripped off the attach points, but I'm not aware of the gear legs failing due to builder applied dry torsional layups. To answer your question, it would only be supposition, but my guess would be excessive squeegy action. Quote Dave Adams Long EZ N83DT Race 83 Link to comment Share on other sites More sharing options...
Edge 513 Posted December 5, 2009 Share Posted December 5, 2009 Looks kinda like micro slurry under the BID. Quote Self confessed Wingnut. Now think about it...wouldn't you rather LIVE your life, rather than watch someone else's, on Reality T.V.? Get up off that couch!!! =) Progress; Fuselage on all three, with outside and inside nearly complete. 8 inch extended nose. FHC done. Canard finished. ERacer wings done with blended winglets. IO540 starting rebuild. Mounting Spar. Starting strake ribs. Link to comment Share on other sites More sharing options...
TMann Posted December 5, 2009 Share Posted December 5, 2009 Hard to tell but if it bothers YOU, sand it down and do it over. You'll waste more time letting it eat at you than the time you'll spend getting it right. I reworked a couple of big parts for the same reason. Quote T Mann - Loooong-EZ/20B Infinity R/G Chpts 18 Velocity/RG N951TM Mann's Airplane Factory We add rocket's to everything! 4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done Link to comment Share on other sites More sharing options...
macleodm3 Posted December 5, 2009 Author Share Posted December 5, 2009 The white is approximately 30% of the gear. I'm sure its all dry areas, and I'm removing the outer bis layers with a hair drier. I got around 1/4 of all the glass off last night using the hair drier. I've attached another picture. Quote Andrew Anunson I work underground and I play in the sky... no problem Link to comment Share on other sites More sharing options...
TMann Posted December 5, 2009 Share Posted December 5, 2009 I got around 1/4 of all the glass off last night using the hair drier. Excellent choice! Quote T Mann - Loooong-EZ/20B Infinity R/G Chpts 18 Velocity/RG N951TM Mann's Airplane Factory We add rocket's to everything! 4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done Link to comment Share on other sites More sharing options...
Kent Ashton Posted December 5, 2009 Share Posted December 5, 2009 With a heat gun and a screwdriver, most any layup will come apart. The fact that you have to resort to that to peel it off sort if indicates it was attached OK. Personally, if it was well-attached, I would have left it alone. That little bit of air wouldn't hurt a thing. But make yourself happy. You're flyin' it. Do you know if the previous owner used Epolite 2427? About 10 or more years ago, this formulation came out as a replacement for Epolite 2426, the original recommended epoxy. 2427 had terrible peel strength and a lot of guys had problems with it. It was a light color epoxy similar to MGS. You could work a screwdriver under the edge of a 2427 layup and rip off a layer like pulling duct tape off a roll. Quote -KentCozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold Link to comment Share on other sites More sharing options...
macleodm3 Posted December 5, 2009 Author Share Posted December 5, 2009 Yeah, these layups MAY have been attached OK. But we must remember... the gear attach tabs attach to these UNI layups. They MUST be somewhat reasonable. Not perfect, but the amount of white that I see, even around the attach tabs, seems a little risky. I think they were built with MGS, but I'm not sure. The glass needs heat to separate, and the lower torsional layups are remaining intact. I'm trying not to mess them up with the screwdrivers. Thanks for the ideas. Quote Andrew Anunson I work underground and I play in the sky... no problem Link to comment Share on other sites More sharing options...
Kent Ashton Posted December 5, 2009 Share Posted December 5, 2009 To offer a little perspective, there is the story in CP 45-3 about Burt test loading a donated canard which had been rejected "due to an extremely dry layup". It still went to just short of 10Gs before the top skin failed in compression and 14G before it failed catastrophically. They loaded 69 25lb sandbags on it and the canard tips deflected 11". Burt also purposefully damaged the skin on a good canard with a test device that "would have punched deep dents in an aluminum wing" and it still went to 12Gs before the sandbags fell off and they couldn't load more. That's what leads me to say that a little air doesn't hurt. Quote -KentCozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold Link to comment Share on other sites More sharing options...
macleodm3 Posted December 6, 2009 Author Share Posted December 6, 2009 I have removed the outer plies of UNI from my gear, and found some more issues. BEWARE when buying parts built by others. This gear was not built with the correct torsional layups. There is only one ply of UNI which wraps all the way around the gear... not the two layers which are supposed to criss cross each other as shown in the plans. This bottom ply is now exposed along the leading edge of the gear, and there are several cuts in the glass. It looks like the builder was cutting with a Fein, and cut too deep. So, the lower layups are incomplete and sliced up for some reason. These cuts were not from removing the upper layers of glass... there are (were) layups over the cuts. I'm removing all the glass from my gear now with my belt sander. This gear might have landed just fine, but with lots of air in the glass and missing and sliced up plies, I'm glad I decided to check it out. Thanks for the ideas... and now I am on to rebuilding this old Feather Lite! Quote Andrew Anunson I work underground and I play in the sky... no problem Link to comment Share on other sites More sharing options...
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