The attached pdf covers Easton fab instructions for their 6061 and 7005 tube sets. Somewhere on the internet might be another one that covers scandium but that'll be more specific to their tubing (assuming scadium is even still available) than the 6061 or 7005 stuff. Several 5xxx series wires are mentioned with 5180 about as specific to 7005 (aka 7020) as it gets being an AlZnMg. It's probably near as damn it unobtanium though... http://www.brazing.com/Pdf/Aluminum Data Sheets/AL_5180.pdf Alcotec also list it but i don't think their parent company ESAB sell it or if they do it's not listed? VBC group was recently mentioned by Appyasme in a different thread and while they stock all sorts of hard to find filler alloys they don't list it either