in high school, i learned oxy/acetylene welding and brazing operations. when i went to community college in the late 80's, i spent 2 years and a semester learning welding processes. gtaw and smaw. i learned a ton of stuff from a master welder who ran the program. i would use a mig welder at work, get off work drive to school,show up early to class, and learned smaw on monday,wed learned gtaw tuesday,thursdays. i couldn't get enough :welding:. needless to say i got a lot of welding in and became addicted to joining metal together. i came across a process that's very old- carbon arc welding... i have been intimate with a gouging torch may times, but never even considered carbon arc as a welding process. come to find out that it was first discovered and used in 1800 and is effective on ferrous and non-ferrous metals. DCEN (straight polarity) is used. i then remember my welding teacher talking about brazing and welding with twin carbon arc on AC. there was 1 half page explanation of the process in our textbook and i had forgotten all about it entirely. i recently reread some of the textbooks and ran across some notes that i had taken on the subject. the first thing that jumped out at me was the process was extremely effective for repairing cast iron, both as a welding process and a brazing process.:thinking: i came to the sudden realization... i never had the pleasure to twin carbon arc braze or weld anything:angry: this was a hurdle i had to jump, here's why... i recently found a deal on a complete vintage 1972 wards(century) 230 ac welder w/ a twin carbon arc torch set up complete with some electrodes . i have an old school JET 370 power hacksaw that has some cast iron in need of repairing...:biggrin: the miter clamping bolt goes into a cast iron clamping plate with poor threading... i got lucky on one side i was able to put a stud into the clamp on one of the clamps, an easy fix. as for the other clamp, i wasn't so lucky. it was poorly drilled from the factory and not much of the thread profile remained. a stud was out of the question for now... i thought to myself, what an excellent opportunity.... to try a new old thing i fired up my recently acquired shop oven(on casters) and preheated my damaged clamp to 300*F i took out the Twin Carbon Arc Rig, slapped a couple 3/8" carbon rods cranked er' up to 90 amps and went to town on a brazing operation to fill up the hole in the cast iron. the process is slow , but, i was amazed that i didn't need flux on the brazing rod to get the puddle to stick. after a few minutes of brazing, BaddaBing ... i put the casting on firebricks inside the oven to cool overnight. i'll post more as i finish the repairs! stay tuned for part 2 thanks for reading!