Idea on how to fix a spinning Tee Nut

Epoxy the the tee nut in place?

Get a glue syringe and fill it with 30 minute epoxy - look for one that is fairly liquid. Shoot the area around the t-nut with the epoxy. Have a couple of Q-tips available to get the epoxy out of the t-nut when it runs into the center of the t-nut (murphy says it will). Once the epoxy is set, run a tap into the t-nut to make sure the threads are clean. If you want to make sure the bolt does not work free again - use some locktite (just remember that the t-nut will now give long before the bolt does, if you do this).

If it does not feel like the t-nut is solid after the first round of epoxy (it feels loose when you run the tap) put another shot of epoxy into it before you set the nut.

If you do not have a syringe, then you can use a gel epoxy, lots of time and a bamboo meat skewer instead of the liquid and syringe...make sure you have 30 minute or 1 hour gel if you do it this way and lots and lots of calm...

You can also put Vaselene or grease on the actual bolt and tee nut threads, running it in while the epoxy is wet. Epoxy won't stick to the greasy surface.

This problem was pretty common on r/c airplanes, where Tee nuts vibrated loose and there was no access to the other side.

Gap filling (medium or thick) CA (super glue) also works well, with the added bonus of being debondable if things go awry. Grease or vaseline also works as a CA resist.

Any chance you can drill a small hole from the metal bar side through the seat back into a t-nut petal (or between the petals of the t-nut) and insert a piece of drill stock, or even a cut off nail, to keep the t-nut from spinning? Leave the pin in place and trim flush on the metal bar side and insert the original bolt... Though epoxy would probably do the job the pin approach would seem to be cheaper, quicker and cleaner than trying to get epoxy in there...

John

Cut a shallow slot in the end of the bolt with a dremmel cutoff wheel to form what is essentially a screw head. Then use a screwdriver to keep the tee nut from spinning as you tighten.