Think of math and fractions here.
5/5 = 1 right.
So 1/5th will only repair one fifth of any damage on an item.
This repair always starts from ZERO.
The reason why nothing is happening for you is because your shield is not damaged enough to be repaired by 1/5th repair skill.
Remember, repair starts at ZERO and you have 50% or 1/2 of your shield left that is not damaged so 1/5th being less than 1/2 will not do anything for you.
Does that make sense?
Tsel
