[NSRCA-discussion] Wing tube phenolic repair "help"

[Rcmaster199 at aol.com]

Anthony, I'll throw my 2 cents in also, FWIW.

I would first try folding back the plastic covering to bare balsa, to about 2 
inches past the end of the phenolic. Then I'd find the center of the phenolic 
socket and scribe a line on the sheeting. Carefully, I would cut a slot just 
large enough to fit 1/8" balsa sub-spars, spanwise. 

The slot would go from the sheeting to the tube depthwise, and extend 2" 
beyond the end of the socket. Same process top and bottom of panel, to sandwich 
the phelolic socket.

Then a good spritzing of water in the slot, poly-u expanding glue in the slot 
touching the socket and foam, med-light glue application of the balsa spars 
and then insertion into slot. Let it cure for 24 hours, sand well and fill if 
needed and re-set the plastic film. 

You will pick up about 10-15 grams per panel, but beats building a new one. 
Unless of course, you want to or the old one was crap to begin with. 

BTW, when building new panels, this technique works exceptionally well except 
the work is done on the foam prior to sheeting. I set the phenolic socket and 
spars in the foam first, sand smooth and then sheet. 

MattK

In a message dated 8/11/2006 11:28:15 PM Eastern Standard Time, 
natpenton at centurytel.net writes:
Anthony
How far does the socket go into the wing ? I quit using a false rib years ago 
but my socket , 1", goes in 18 ins. The tube goes in about 16". The simpliest 
way to stabilize the socket is with spray insulation foam, one injection hole 
3/8 ?and one vent hole 1/8 ?. The kind I have used does not attack styrofoam. 
It is a fast repair and you have not lost anything if it fails for some 
reason.
----- Original Message ----- 
From: Anthony Abdullah 
To: NSRCA Mailing List 
Sent: Friday, August 11, 2006 3:36 PM
Subject: Re: [NSRCA-discussion] Wing tube phenolic repair "help"


Dean,
I hadn't thought of that, but wasn't that repair kind of heavy? I think it is 
hilarious that you covered them in yellow!

I am fairly certain that I will use the false rib from the bottom technique 
to fix it. I will take great care to cut a uniform slot where the rib fits in 
snug, particularly around the phenolic. That should provide lots of surface 
area to transfer the load to the entire foam core wing panel. 

Next question:
What should I make the rib out of? Would a balsa rib laminated in carbon 
fiber be strong enough or should I just go with light ply? Of course weight is an 
issue. 

Should I still use Poly glue or would foam safe CA or 30 Minute epoxy be 
better?

Thanks again for all of your great suggestions.
Anthony
Dean Pappas <d.pappas at kodeos.com> wrote:
Hi Verne, Hi Anthony,
I had to do such a fix maybe 14 years back on a Desire 120.
The foam started to tear away from the tube, just as you describe.
I poked a 3/4" diameter hole in both sides of the wing just inboard of the 
end of the tube.
Then I took a piece of broomstick, sanded a concave to mate to the tube, and 
carved and sanded the other end to be flush to the top of the sheeting.
They went in with epoxy.
Then a pair of 6" long, by 1-1/2" wide 1/32" plywood scabs were glued to the 
outside of the sheeting like ribs.
That way, the tube was supported by a 6" wide swath of sheeting, top and 
bottom, with the load transferred by the broomstick columns.
I covered the scabs before gluing, and because I wasn't bashful, I covered 
them bright yellow which was not present anywhere else on the plane.
I think it was '92.
Dean


Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com 
-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org 
[mailto:nsrca-discussion-bounces at lists.nsrca.org]On Behalf Of Verne Koester
Sent: Friday, August 11, 2006 10:33 AM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] Wing tube phenolic repair "help"


Anthony,
There should be a false rib near the end of the socket, usually made out of 
1/8 lite ply. If there's not one there, you need a new set of wings unless you 
can figure out a way to put one in there after the fact.

Verne
----- Original Message ----- 
From: Anthony Abdullah 
To: NSRCA Mailing List 
Sent: Thursday, August 10, 2006 10:42 PM
Subject: [NSRCA-discussion] Wing tube phenolic repair "help"


I was just about finished setting up my Odyssey when I noticed that the wing 
seemed a little loose. If I hold the fuselage the right wing panel can wiggle 
up and down a noticable amount. I thought that maybe the tube mount at the 
fuse was loose but that was not the case. As it turns out, the phenolic in my 
completed wing is loose about 3/4 of the way down and is wiggling around. It 
almost feels like the foam in the sheeted foam core wing has been somehow 
dislodged and the phenolic is in just a hollow cavern instead of solidly glued to the 
wing. It is still glued solid at the root so it won't slide out, but it 
obviously can not be flown in that condition.

Question:
How do I go about repairing the foam that the phenolic mounts to? The wing is 
sheeted, covered, and trimmed (complete) and I would like to keep from having 
to start all over again. Getting out the old one will also be an issue as it 
is still partially glued in. 

I am open to any and all suggestions.

Thanks in advance
Anthony   
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