Just a reminder from someone who mods.....while the above video is cool, it misses a few key points:
1. SAFETY....this is acid, use the appropriate gloves....this dude just dipped it in.
2. If on a folder, you will need to use nailpolish to cover up things like the pivot hole, detent ball, lockface (if a framelock) - I have seen guys ruin their blades because they didnt cover the pivot, remember the acid is eating away the metal, this will affect lockup, pivot, and more if not done properly.
3. the guy in the video used an agitator, thats great, You can also use a rock tumbler (avail at craft stores) or even a cement mixing drum....I dont reccomend the "shake it till you make it" method as the results are less effective.
4. SAFETY!!!!!!!!!!!! I have seen people burn their hands and inhale fumes....this is important enough to mention twice
5. use rounded or polished rocks, or ceramic media. rough rocks will chip your blade.
6. when stripping off coatings from blades, use Aircraft Stripper avail at most autoparts stores, and a wirte brush, and gloves as that too is nasty.
7. remember the acid dip will ruin your blade geometry, so if you are not proficient at creating/maintaining an edge, have someone do it for you.
8. learn how to properly dispose of yur used acid, you cant just flush it or dump it.