Caswell has a very good reputation with people using their products, so it will not wear off the latch, just that there will be some noticeable slight wear where any of
the metal surfaces contact or rub on each other. The biggest deal is in making sure
you take the time to prep the part, by either
putting in evaporust, or bead blasting. If you
do evaporust it, make sure your last step is
using glass bead.... so the chemical your using has good/great adhesion! Also, if you
Get some bare metal on your latch, you can always put some WD-40 on it, to keep from rusting. Hope this helps your cause. Good luck.