Doug Fattic 

I’ve come to prefer oxypropane more than oxyacetylene for any framebuilding application including fillet brazing as long as I am using the best propane specific brazing equipment. This was reinforced recently when a student came to make a fillet brazed transportation style of frame in a one week class. He already has an oxyacetylene setup so we started out using mine. He wanted to try propane after learning of its cost savings and buying convenience. It wasn’t long before he preferred it for brazing too – especially fillet brazing. It had been awhile since I had used acetylene to fillet braze (which I started using in 1975) and realized I prefer a multi-port propane flame pattern as well. I started using propane as a fuel in 2004 when we began to build transportation style frames ourselves for a charity project in Ukraine after the XB3 factory in the city of Kharkov stopped making the kind of frames we needed.

However, it is necessary to use propane specific equipment (especially multi-port tips) to get the sharpest and most stable flame pattern. I'll post pictures and explanations in a new separate subject thread so it is easier to refer back to when researching information in the future.