The "black gloop" I use is high temperature silicon but I also safety wire the springs, in the event that the spring brakes there is less chance of a part "flying" loose in my engine compartment.And there's some black gloop you squeeze onto the springs to stop them moving and eventually breaking. Nev
A lockwire has very limited ability to resist a nut turning, in my view. If you were in a hurry you'd snap them easily by just undoing the nut or bolt by driving a ring or socket over the wire and undoing the particular fitting. Yes they are supposed to be fitted in regard to the direction they unwind being immediately noticed as the wire would have to break, before the Bolt moved any real distance. It is NOT any guarantee the bolt has been torqued to the right setting. that's often done with a dob of (usually) yellow paint but that's not foolproof either. I think lockwiring provides a visual check nothing has moved since it was lockwired and not a lot else. Nev
This is to misunderstand how a bolt works. When a bolt comes undone during use, the force retaining it is not the torque applied when fitting it, it is zero. When you tighten a nut onto a bolt it stretches the shank of the bolt (it is elastic). This puts a constant force holding the items together. When there is vibration it causes an oscillating force on the bolt shank, the combined effect is that the net force in the bolt shank increases and decreases around the mean (torqued in force). If the vibration is strong enough the peaks and troughs of the oscillation are greater than the torqued in force, at which point there is no force on the face of the nut during each trough. Of course the vibration does not affect lock wire or loctite in the same way so they tend to keep the nut from turning (notwhithstanding any fatigue and shear effect).It's actually a force of a very small order compared with the torqueing force and any force required to undo most nuts that are not loose, already. You only have to break one of the two wires through the bolthead. On a filter it's got a much bigger radius, To be fair many locking devices don't have a lot of strength in their own right. A split pin and castellated nut often permit adjustment, and the nut is not tight at all. Some others have a preload and may be pinned or staked into a groove to lock them. Nev
The origin of safety wire was to prevent the loosening of turnbuckles on control cables in earlier aircraft.Can anybody provide an example where safety wiring has prevented an accident?
I am not really doubting that safety wiring is good etc. It is just that I don't know if it has ever worked as intended.