<HTML><FONT FACE=arial,helvetica><FONT SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">In a message dated 10/14/2002 6:51:15 PM Eastern Daylight Time, DGundling@compuserve.com writes:<BR>
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<BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">Subj: <B>Structural Repair </B><BR>
Date: 10/14/2002 6:51:15 PM Eastern Daylight Time<BR>
From: <A HREF="mailto:DGundling@compuserve.com">DGundling@compuserve.com</A><BR>
Reply-to: <A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
To: <A HREF="mailto:discussion@nsrca.org">discussion@nsrca.org</A><BR>
<I>Sent from the Internet </I><BR>
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Had a wierd one while flying Saturday. The wing on my Legacy Lite went from<BR>
slight dihedral to noticeable anhedral in flight. Was able to land the<BR>
plane OK. On checking I found out the wing had failed right at the center<BR>
of the two wing halves in the middle of the fuselage. Would have expected a<BR>
wing failure to occur just outboard of the center section fiberglassing.<BR>
The failure was almost like a knife cut at the wing joint. The fiberglass<BR>
and wood on either side of the break were pretty much OK. The fiberglass<BR>
was stuck to the wood and the wood was stuck to the cores (wood put on with<BR>
epoxy). Question, what is the best way to repair the wing. Put new<BR>
fiberglass and epoxy over the old or take the old fiberglass off and stick<BR>
the new glass to the wood. I am leary of this as I am liable to tear the<BR>
balsa wood off while trying to get the old fiberglass off. Will brace the<BR>
joint with carbon fiber this time. How far out should I run the new center<BR>
joint?<BR>
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Any ideas on a better way of doing it appreciated.<BR>
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Dave</BLOCKQUOTE><BR>
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Dave,<BR>
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It sounds like too much sanding at the wing center joint. It also sounds like whatever glass you used, would have been plenty strong, since the wing did not really fold completely. Apparently there was enough strength left, perhaps from the bolts, since you landed the plane. <BR>
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To repair, roughen up the glass in the center section with 60 grit paper and lay another piece of 6 oz/yd minimum over that. You just have be certain that the glass is roughened very well so the fresh epoxy has bite. I would not try removing the old glass since too much of the wood may be removed.<BR>
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For one piece wings, my procedure is to first make sure the skins from the two panels mate properly with minimal gap, and then glue these together with Pro-Bond and water. I let this cook off overnight, and then come back, touch up the foamed Pro-Bond at the joint a little, and then lay a 1" piece of 4 oz cloth all around the center. Then I lay another piece of similar cloth, about 5" wide, over the first. The first piece is a little insurance in case I get a little heavy handed with the sandpaper on the second, wider piece. I have never had a wing center section fail (or stab, except, 2 oz is plenty on stabs)<BR>
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Matt K</FONT></HTML>