Woodwork

[Bill Poynter]

Here's a photo of a Langley twin from about the same time period as the Cadet.  Even the cowlings and wheel pants were made from wood.  Only two were built and one of those was based here in Louisville for a short time in about 1965.

[Bill Poynter]

I'm wondering if anyone has devised a solution for the problem of screw holes in wood becoming enlarged and no longer properly fitting the original size screw.  It occurs most often where the screw is only going into the thin plywood skin.  I really hate putting in larger screws and thought I would see if someone knows of a practical method of repairing these reamed-out holes. 

I've considered saturating the holes with thin C-A glue to strengthen the wood in the area of the hole, but that does nothing for a hole that's already oversize.  Perhaps one of the products made for wooden boats would work.

[Dan C]

All,
I have dealt with the same issues in the Bellancas that I own and operate. I can say that screwing into and through wood can cause problems for airplane owners. This is not a problem in the furniture and cabinet making industry because the fasteners stay put for the life of the product. With aircraft, you have panels and fairings that are not only removed periodically, but subjected to vibration and flight loads. After 60 years or so, and a few thousand hours, that hole which originally contained a #6 screw, now barely holds onto a #10.
There are various threaded inserts that can be buried in or attached to wood structure. I recommend these. You can find them at aviation supply houses or your nearest hardware store. The only difference will be that you will use machine screws instead of tapping screws. These screws are available in slot or Phillips head. I'm sure Culvers came with slot head truss screws.
Dan   

[Bill Poynter]

I've dealt with this issue on one of the Bellanca Vikings that I've owned.  On that Bellanca, the areas where screws were fastened to plywood were accessable from the back side.  Because of that, Bellanca used fasteners attached to the back side of the skin.  I've replaced a few of those.  On the Cadet, when a hole is enlarged, you're faced with trying so solve the problem from the outside.  The blind nuts that I'm aware of all rely on the mechanical friction resulting from being squeezed onto the skin.  I'm not sure that would work so well on plywood.  Is there another type that would work well on plywood?

[Dan C]

Bill,
How about a photo showing all the parts you are dealing with. Are you attaching something to plywood skin where you can't get to the backside? Thickness of the ply?  Bear in mind that I don't have access to a Cadet.
Dan

[Bill Poynter]

Some of the screws securing the fairing located on the horizontal stab, only go into the plywood skin.    It's that way on both of my Cadets, but I don't know if that holds true for all of Cadets.  There's no access to the back side of the stab skin.    We need to have recommended procedures for repairing reamed-out screw holes for both types of holes though.