Check these out: http://www.brownells.com/.aspx/pid=4942/Product/SUPER_BLACK_INSTANT_TOUCH_UP_PENWith this kind of response the choice is easy... "Birchwood Casey Super Blue". Thanks to all for responding and thank you MemphisMachinists for the recommendation of "tool black", I will research that product before I order.
Best Wishes To All: Mike
I have not used this myself, anybody try one of these??