[header] How to make an arc carbon lamp [title] Open the 6 volt lantern battery with a screwdriver, hack-saw, etc. [step] , and remove the black carbon rods. There should be about 4 of them, and they should be about 3/8 " thick. 
Tutorials on exactly how to do this are available on youtube, though wear gloves in the procedure, as other chemicals inside the battery aren't healthy. [title] Put two holes opposite of each other in the tin can so the carbon rods have at least 1/8 " on all sides.