Iron Palm Training

Basic Iron Palm training starts with sand filling your Iron Palm bag. Then you have two options: increase the striking power, or forgetting the bag and striking directly on wood. Remember that some fabric is always necessary regardless of the surface you choose to impact onto, until you skin becomes so hard and conditioned that you can forget that layer of fabric as well.
Since Iron Palm is not a workout for muscles, this exercise won’t make your hands bigger. Bone density, on the other hand, is heavily stimulated by performing this exercise. Please have a look at Dr. Wolff's in-depth studies which clarify and properly explain Bone density applied to Martial Arts.
To start with, you can hit your bag for a total of 100 incremental rounds (each round = four hits per single hand, as shown in the video)
You will get to break a brick, just keep in mind two things: first, there's no breaking without proper Hard Qigong training - second: when attempting to break your first brick, your mind must be set on giving power for two bricks - no hesitation - you have to focus just on that. Any intrusive thought like "am I going to break it..? Will I get hurt..?" will just sabotage your spirit, and your body as direct consequence. First win then fight, remember.
Just some canvas on bare steel will do. You can try with two or three layers of canvas at the beginning, then switch to two, then one, then strike directly on steel. As long as surface is perfectly smooth (you can sand it with P180/P240 grit sandpaper)
Everything that is gradual, carried on for years, and with proper breaks for the body to heal is never dangerous. Of course we are talking about advanced BMC training, that requires a proper preparation with softer tools.