I try to buy soldering supplies from a large electronics supply store. Look for Weller brand soldering irons and replacement tips. Simple 37-47 watt soldering irons with tips that are held into the barrel with a set screw are best, screw-in types tend to seize up and tips may become hard to remove. Use flat sided "chisel" type tips for soldering wires to connectors. Pointy tips are for circuit board work. Tin tips while heating up for the first time, keep wiping tips on a damp paper towel pad and applying fresh solder before, during and after soldering. Touch the iron to the wire or terninal and feed a little solder into the junction of iron tip and wire or terminal to conduct heat, then add more solder to fill the strands and tin the wire or tin the terminal. Hold tinned wire against terminal while reheating the two with
Other options = silicone tubing, nylon washer, using SF props, switching prop brands, not losing the precious adapters [not crashing], modding APC or Hyperion or the new GWS adapter rings or these?], sticking with 7035 props
These Park 250 rings?
Here's another source of almost-the-right-size adapter rings, the FalconInserts.
And here is another, the GWS 3-blade prop inserts.
Alternatively, glue the stock ring adapter to the motor? Then maybe bevel the prop hole a little with an 8mm ball head burr? so it slips off more easily on impact?