Would you be able to show a picture of what you want to do? I'm not going to judge motives and just treat it as a welding question. First DO NOT take it to a welding shop. It would be a extremely rare to find a welder in a job shop that has been trained to weld high carbon steel. I taught at a very good welding school and there is no way we could get a class in a two year program up to welding high carbon steel. In fact none of the instructors including myself were qualified to weld it even though we were all very experienced CWI's (certified welding inspectors) though we would have a idea were to start. Remember that a class can only move as fast as the slowest students. A GTAW/TIG welder is the most precise welder that is commonly available. You may be able to tig braze it. If you add any filler metal into the weld it will be visible over time. To properly weld it you would require a high preheat and postheat and you would have to re heat treat it. Brazing is by far the best option but its still likely to destroy the temper. Also if you weld it you would have to find the right filler metal or use something like INCO 625 for dissimilar metals. These filler have a super high nickel content and will not match at all. Over time the repair will become more visible. I don't know why a repair of something like a broken tang would be a big deal so long as it is disclosed. Any repairs in the blade are not going to fool anyone. If you don't do pre and post heat as well as a stress relief or it is very like to crack at some point if it doesn't do it immediately. If you have any questions about welding I can answer those but I would need to see what you are trying to do.
It probably wouldn't hurt to be clear about your plans for these knives.
It probably wouldn't hurt to be clear about your plans for these knives.
