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Fastening a panel to Alum. 3/4" square tubing.

Ron B.

Well Known Member
Having trouble coming up with a viable solution to screw an alum. panel to 3/4" X 1/6" thick alum tube. This is a removable panel and my plans call out for rivnuts. Every time I install these panels I need to drill out 3 or four of the screws and the rivnut. The rivnuts are the counter sunk type and the counter sunk thin tubing is just not enough to hold the rivnut from turning.
I might have to re-order the two tubing pieces and take the time to slide nutplates up to each hole and use pulled rivets to secure them.
I have not mastered installing rivnuts and I am ready to say they won and give up on them.
 
I hope you meant 3/4" x 3/4" x 1/16" tubing:)

There are rivnuts and there are rivnuts. Have a look at this site.
http://www.rivet-nut.com/about-rivnut.html

Aluminum rivnuts are common, but so are steel rivnuts. There are also Hexnuts and locking rivnuts that are keyed to the tube so they don't rotate.

The proper tooling is essential. I'm sure you can make them work in your application with the proper rivnut and tooling.
 
Nutplate

Just an idea I've used before. Drill the part for nutplates. Snake a piece of waxed lashing string through the screw hole. Slide the nutplate on the string. Tie a nail to the end of the string. Pull it back in and secure the nutplate with a cleko. Takes a little fidgeting with an awl to center the holes. Rivet with a pop rivet then do the other hole. Remove the string.
 
If you don't want to try to fish individual nut plates in there, then you could back drill a strip of something like .020, rivet nut plates to the backer strip, then slide it in place.
 
I hope you meant 3/4" x 3/4" x 1/16" tubing:)

There are rivnuts and there are rivnuts. Have a look at this site.
http://www.rivet-nut.com/about-rivnut.html

Aluminum rivnuts are common, but so are steel rivnuts. There are also Hexnuts and locking rivnuts that are keyed to the tube so they don't rotate.

The proper tooling is essential. I'm sure you can make them work in your application with the proper rivnut and tooling.

Yup, 3/4" X 3/4" is the material. I bought the squeeze tool and that hasn't worked well for me. Either pull out the thread in the nut plate (pull too hard) but if you stop before the thread fails the rivnut turns. Broke the shank on the # 8 (pull too hard) but again if you don't it rotates. The best tool I tried was the cheap slid type puller ACS sells.
Thanks for the tips , but I quite sure I'm done with rivnuts.
 
Just an idea I've used before. Drill the part for nutplates. Snake a piece of waxed lashing string through the screw hole. Slide the nutplate on the string. Tie a nail to the end of the string. Pull it back in and secure the nutplate with a cleko. Takes a little fidgeting with an awl to center the holes. Rivet with a pop rivet then do the other hole. Remove the string.
That will probably be my solution but will require new tubing as the counter sunk holes are too large now for nutplates.
 
If you don't want to try to fish individual nut plates in there, then you could back drill a strip of something like .020, rivet nut plates to the backer strip, then slide it in place.

The tubing is about three ft long and the strip you are talking about would push in , in the center and make starting each screw difficult, but thanks for the option.
 
I have had good luck with red Loctite to help prevent rivnuts from spinning. Recent Kitplanes article recommends epoxy. Also, when able it can help a lot to avoid countersinking the flush rivnut perfectly flush in thin tubing.
 
I tried epoxy on a few and it didn't seam to help. I think the tubing is just too thin. Too thick to dimple and not thick enough for the rivnuts to grab. I think I would have been better off to leave them proud like you mentioned. I see you are flying an AirCam, these tubes are for the enclosure in the baggage area.
 
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