E6000 Glue Cap (that fits)
E6000 is amazing, there's no substitute for it, but it's super annoying when the caps split and your whole tube is wasted
I tried another design and it came out tiny, wasn't scaled right and the proportions were off, so i made my own
I didn't bother with the threads since flat cap threads on just fine, I printed with pla, 10 line adhesion brim, 60% infil, it would probably work even better in tpu, but my tube now has a cap on it and it's sealed, so good enough for me
I did thread it on while it was still hot to make it conform a little better and it's on there pretty tight now
Also attaching sketchup file in case anyone wants to mess with it
Enjoy!