Originally Posted by
robalong
After so many years of turning nuts, I have a good success rate. How so? I remember the early days, when a rusted nut would beat me, and bring the work to a halt.
I'll start with this:
I still don't understand how this works, I just know that it does. Sometimes, a nut can be removed with fingers once the torque is released. But it's commonplace to have to use a wrench all the way if rust and gunge need to be overcome.
So ... half a turn backwards (release), a full turn forwards (tightening). Half a turn back, a full turn forwards, until the nut is off. Instead of powering on in one direction (release).
Explanation of why/how this makes it much easier to remove a stubborn nut will be most welcome. It helps to attack the visible thread with a wire brush, and to dab a spot of oil on it before starting to wrench.
Corrosion is the process of making a metal into an oxide. The oxide has a different crystalline structure to the crystalline structure of the metal as well as an increased volume. Iron oxide has a lower density than iron but the process that forms it results in an open structure with pores and air pockets. Moving the bolt back and forth grinds that rust into finer particles by getting rid of the pores. Penetrating oil makes the grinding process a bit easier as well as allowing uncorroded material to slip easier against other metal that hasn’t been corroded.
Greasing bolts before installation provides a barrier against water infiltration which reduces the chance of oxidation.