Holes in Fuselage for Windshield Trim

[Mushroom]

I know from being on this sight that there should be no holes in the tube fuselage so I was surprised to see these holes on the right side door post for the windshield trim. According to the piper drawings the screw should be offset in the door frame sheet metal from the post. The holes in the sheet metal though are lined up top dead center with the post. It almost looks original, could this be a boo boo from the factory? With that said I’m looking for a direction. The upper tube is still solid. Should I weld them shut?, plug them with a cherry rivet?, or just install the trim like it was and let the screws plug it? Piper drawing and a picture of the holes are attached. Any advice is appreciated.

Patrick Morell

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[Gilbert Pierce]

That is a main structural member. The factory isn’t going to put holes in that tube.

[Paul Watts]

Mine looked just like yours, the holes were drilled nearly 1/2" from the edge (as I recall), and the screws went straight into the tubing (zero space between the door frame and the tubing). The plane was 50+ yrs old, and had been recovered twice. Still, if they were not the factory holes, someone did a fantastic job of hiding the original holes. I guess someone might have replaced the door/windshield frame???

Anyway, I fretted over what to do for awhile, then welded up the tubing and frame and drilled new holes in the frame and trim 1/4" from the edge. It turned out OK, but (again, as I recall) 1/4" type "A" screws still hit the tube before pulling up tight; I ground the 'point' off the screws and called it good.

[Steve Pierce]

Weld the holes up and drill the sheet metal where it will not penetrate the tube. I have rebuild several late model (79-82) Super Cubs where Piper drilled into the tubing instead of the channel like the drawing shows and every other Piper I have ever worked on.

[Mushroom]

Thanks for the reply’s everyone. I’ll have them welded shut and redrill the holes carefully. I went back and looked at the “Andy’s Pacer Restoration” thread and saw the same holes in that aircraft also.

[Glen Geller]

Just curious for Steve's perspective and that of you others who have done these kind of tubing repairs.
Should the inside of the tubing have something like ACF50 or other corrosion inhibitor applied before welding shut the errant holes?
Would you drill (and later weld closed) the bottom end of that tube member to let water out, or punch the bottom to verify it's not dangerously thin/corroded?
Seems there could be some bad stuff in the tubing from years of exposure.
Or was that screw that penetrated the tubing wall a good enough seal?

GG

[Steve Pierce]

I remove those channels on a rebuild and then blast. If there are holes drilled in the tube I look even closer and use a punch at the bottom of the tube. That is where the water collects and corrosion starts. Replaced a few tubes over the years from internal corrosion, all of them had a hole drilled in them somewhere. Usually dealing with external corrosion.