oil black’n shit .

oil black is an old technique used w/ MAPP gas to heat treat metals and change the outer appearance to be a black , grey or blue color. This is not an easy or fun thing to do but once you've got it down, you can make some super strong, cool lookin' parts that a good file will have a tough time biting into .

MAPP gas heating of small parts

MAPP / oil dip cup

After dip and cooling