I'm no YECer largely because of radiometric dating but answers like that don't really help your cause.
This is from the AIG link concerning the use of isotopes other than C-14:
The isotope concentrations can be measured very accurately, but isotope concentrations are not dates. To derive ages from such measurements, unprovable assumptions have to be made such as:
1. The starting conditions are known (for example, that there was no daughter isotope present at the start, or that we know how much was there).
2. Decay rates have always been constant.
3. Systems were closed or isolated so that no parent or daughter isotopes were lost or added.
Now, you appear to have some background in engineering. It should be snap for you -- in your own words -- to refute this.
Go for it.
Seeing as moon rocks, meteorites, martian rock, as well as various rocks from earth itself all show dates of well over 1 billion years old, I'd say that point 3:
"3. Systems were closed or isolated so that no parent or daughter isotopes were lost or added."
is actually more than an assumption in the absense of known mechanisms to take or remove daughter isotopes for each case. It's would just be too much of a coincidence for all those different sources from different locations to all be messed up the same amount by their different environments.
AIG throws in some science then throws some false science in the middle to conclude that their point is valid. They hope to impress the ignorant that don't know the difference.