Andy Bailey gave a good comment on our post about using magnesium fire starters. It sounds like good advice, but like Andy I have moved on and use a fire steel striker and Vaseline cotton balls.
“I have a little experience using these magnesium fire starters: There is a bit of a trick to it.
#1. Bring along an old junky knife. The blade that you use to scrape the magnesium is going to dull very quickly, but in my experience, a dull knife works about as well as a sharp knife for this task.
#2. You need LOTS of shavings to start a fire.
THE BIGGER THE PILE OF SHAVINGS, THE MORE LIKELY YOU WILL BE SUCCESSFUL AT STARTING A FIRE!
The magnesium burns with a quick flash, and then it’s done. You might spend 15 minutes scraping enough magnesium to light 1 fire. Make a little pile about as big around as a quarter, or better yet, a half-dollar. This is harder than it sounds, because the slightest breeze will scatter the shavings all over the place! It works really well to scrape the magnesium into a container of some sort (like a bowl or pot) so that it doesn’t blow away and you can carefully pour it out into a neat little pile on the ground to light it.
Lighting Vaseline-coated cotton balls or char cloth with a fire steel is far easier and a lot less work than scraping magnesium. But the magnesium bar is more convenient to carry (1 piece, waterproof, small).
I personally find it far easier to carry a fire steel and cotton balls and char cloth.”