I made one of these for a homemade welder that had too little open circuit voltage for keeping an arc on a standard stick rod. It did not work well, and it sat unused for years.
Recently, I had to set a fairly large tenon for a blacksmith project that contained a melted in bronze bearing in the other end. A coal forge would have been fiddly, since the bearing would have been heated quite a bit while getting the tenon up to temperature. So, the assembly was clamped in a post vice, and the protruding tenon heated with this carbon arc torch. It did not work so well. The bearing did not get burned, but the arc "flame" was too localized, and ended up singing the tenon in unattractive ways. Eventually, this worked, but the job looked sloppy. Fortunately, the tenon joint was not the only source of strength, since there were scrolls and collars to keep things snug.
The loud bright "flame" tends to make you rush and do silly things, especially if there is a hammer in your right hand, since the carbons are always getting shorter, and you are adjusting them. It is not completely certain that they are cheaper than gas, especially if you use oxy-propane for heating.
Recently, I had to set a fairly large tenon for a blacksmith project that contained a melted in bronze bearing in the other end. A coal forge would have been fiddly, since the bearing would have been heated quite a bit while getting the tenon up to temperature. So, the assembly was clamped in a post vice, and the protruding tenon heated with this carbon arc torch. It did not work so well. The bearing did not get burned, but the arc "flame" was too localized, and ended up singing the tenon in unattractive ways. Eventually, this worked, but the job looked sloppy. Fortunately, the tenon joint was not the only source of strength, since there were scrolls and collars to keep things snug.
The loud bright "flame" tends to make you rush and do silly things, especially if there is a hammer in your right hand, since the carbons are always getting shorter, and you are adjusting them. It is not completely certain that they are cheaper than gas, especially if you use oxy-propane for heating.