what do I actually need if I want to braze with propane? - and without oxygene

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Hello dear experts, i am new to this forum - and i hope that i put this thread to the right forum and sub-forum. what do I actually need if I want to braze with propane?what is aimed: I want to build a racing bike frameFirst of all: I hope that this is not too much off topic here. No question here about welding in the narrow sense of the word, about TIG MIG and similar techniques, etc. - no, today it's about something else.The question is: what do I actually need if I want to braze with propane?What is aimed: i want to create a bikeframe.So the question is: Do you definitely need oxygen, or does it also work with a so-called "air-breathing" burner?In other words: without any special oxygene. Can we also process brass solder, or just silver solder?Note: air-breathing is the name given to all those burners which, in addition to the gas (let's say acetylene or propane), do not add pure oxygen, but only "utilize" air from the environment. The small disadvantages: If we re doing so: There is also nitrogen here. (see below)Fuel flame temperatureto the temperatures: Flame temperature - WikipediaThe literature usually states the highest temperature that can be measured in a flame under ideal conditions. Examples:with air with pure oxygenPropane / butane 1925 ° C 2850 ° CHydrogen 2130 ° C 3080 ° C [1]Methane (natural gas) 1970 ° C 2860 ° CEthyne (acetylene) 2250 ° C 3030 ° C
Reply:A propane/air torch may work but it has to be a hot enough flame. One of the torches for brazing large size copper tubing should work. I don't think you need silver solder but you need a properly soldered joint. I think it would be good to practice on some of the material you will be using. A torch like below may work. A torch that threads onto a disposable cylinder is not going to work. A racing bike frame is not considered a relatively easy project. With heat comes warpage and you will need some sort of precision jig to keep everything aligned. It's pretty much known that oxygen accelerates combustion which is why when mixed with a fuel gas gives a higher temperature.  https://www.airgas.com/product/Gas-E...p/VIC0386-0006
Reply:My Very first project was a track racing bike frame.  Raced it in US Olympic  trials and a World cup/pre-olympic race in Atlanta in 1996.  Had aspiration of being famous and branding a bike line.  I used oxy/mapp Benzomatic setup for brazing.  It was not an ideal setup. Used Columbus SL tubing.Good luck
Reply:I think you're gonna have a tough time brazing without oxygen. I have an air-acetylene torch like what plumbers use (and acetylene burns hotter than propane) and I tried brazing steel with it, and it was darn near impossible. Maybe if you sat there forever and a day, you could get it hot enough, but I ran out of patience.Good luck, and let us know what you come up with, and how it works out. Welcome to the forum.
Reply:A DIY forge burner would do it. So if you cannot find anything, then perhaps you could make something....relatively easy and cheaply.  The issue had with the small torch was too localized heat for the lug. And the fork crown will take a bunch of heat. Might need something smaller for bosses and braze-ons???
Reply:The guy that I watched building high end road racingbike frames had the whole joint almost up to brazingtemp and then went around heating/ adding filler to make it flow between lug and tubes. He used oxy-acetylene. With my experiences attempting to braze with air/acetylene,I’m thinking you’ll never be able to heat the entire joint enough to make the filler flowinto the joint dependably.Miller a/c-d/c Thunderbolt XLMillermatic 180 Purox O/ASmith Littletorch O/AHobart Champion Elite
Reply:What do you need? A lot more patience than I would ever have . If it's thin enough it might be doable. Why no oxygen? Tig brazing is another option
Reply:You need a TurboTorch with the correct size tip,,https://www.amazon.com/TurboTorch-03...s%2C174&sr=8-1I have no idea of the size you want to braze, but, I have a T-6 TurboTorch tip that will get a 1" round steel solid bar hot enough to braze,,with only using propane, no oxygen needed,,This pic looks like he is brazing copper tube, with the TurboTorch
Reply:forge burner or weed burner might do it with natural aspiration/propane.  Forge burners are pretty cheap on ebay, weed burners are available everywhere.I doubt the little bernzomatic units will have the output.
Reply:Originally Posted by SweetMKThis pic looks like he is brazing copper tube, with the TurboTorch
Reply:Hello dear Friends, many many thanks for the replies - more much much more than expected. Thanks for the ideas and for sharing your experience. I agree with you - and spend some more bucks for a nice system ;Acetylene/Omy friend has got Propane / Oso i can make some tests and get more insihghts on both systems.Again - many many thanks for all your great ideas. This forum is so awesome,. Keep it up - it is the best place for the topic Framebuilding.have a great day
Reply:This shouldn't be very hard for you to do, friend. Building your own propane forge burner (the burner is just the torch) is very cheap and easy (instructions are everywhere online, materials are WIDELY available).A purchased forge burner or weed burner should be around $30 USD (in the USA).  Comparable to a high end plumping torch.  They will certainly get you where you need to go for brazing nearly any thickness of tube.For brazing something with more bulk they can usually get you there too, IF the item is REALLY big you can preheat on a BBQ grill/gas cooking stove/bon fire and use the torch as a spot heater.
Reply:Getting the right size of tip for the torch regardless what fuel gas is used is the important part. The Turbo Torch line has some models and tips designed for soldering larger diameter copper pipe. A welding supply and/or calling Esab would help you get the biggest and hottest tip Turbo Torch set up. Ideally oxy/propane (or oxy/acetylene) would be the best option but air/propane may work OK. You could always use a hand held torch on a disposable propane cylinder to provide additional heat (2 torches).